+(4.2.7p344) 2013/01/03 Released by Harlan Stenn <stenn@ntp.org>
* Refactor and enhance mdoc2texi.
* Make sure agtexi-file.tpl defines label-str.
* Cleanup to ntp.conf.def.
#
# EDIT THIS FILE WITH CAUTION (invoke-ntp.conf.texi)
#
-# It has been AutoGen-ed January 1, 2013 at 11:33:54 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:09:25 PM by AutoGen 5.17.1pre11
# From the definitions ntp.conf.def
# and the template file agtexi-file.tpl
@end ignore
directory,
but could be installed elsewhere
(see the daemon's
-@code{-c} command line option).
+@code{-c}
+command line option).
The file format is similar to other
@sc{UNIX}
configuration files.
Comments begin with a
-@quoteleft{}@quoteright{}#
+@quoteleft{}#@quoteright{}
character and extend to the end of the line;
blank lines are ignored.
Configuration commands consist of an initial keyword
The rest of this page describes the configuration and control options.
The
-"Notes on Configuring NTP and Setting up a NTP Subnet"
+"Notes on Configuring NTP and Setting up an NTP Subnet"
page
(available as part of the HTML documentation
provided in
@file{/usr/share/doc/ntp})
contains an extended discussion of these options.
In addition to the discussion of general
-@ref{Configuration}Configuration
-Options
-,
+@ref{Configuration Options},
there are sections describing the following supported functionality
and the options used to control it:
@itemize @bullet
+
@item
-@ref{Authentication}Authentication
-Support
+@ref{Authentication Support}
@item
-@ref{Monitoring}Monitoring
-Support
+@ref{Monitoring Support}
@item
-@ref{Access}Access
-Control
-Support
+@ref{Access Control Support}
@item
-@ref{Automatic}Automatic
-NTP
-Configuration
-Options
+@ref{Automatic NTP Configuration Options}
@item
-@ref{Reference}Reference
-Clock
-Support
+@ref{Reference Clock Support}
@item
-@ref{Miscellaneous}Miscellaneous
-Options
+@ref{Miscellaneous Options}
@end itemize
Following these is a section describing
-@ref{Miscellaneous}Miscellaneous
-Options
-.
+@ref{Miscellaneous Options}.
While there is a rich set of options available,
the only required option is one or more
-@code{pool}, @code{server}, @code{peer}, @code{broadcast} or
-@code{manycastclient} commands.
-@node Configuration
-@section Configuration
+@code{pool},
+@code{server},
+@code{peer},
+@code{broadcast}
+or
+@code{manycastclient}
+commands.
+@node Configuration Support
+@section Configuration Support
+
-Configuration
-Support
Following is a description of the configuration commands in
NTPv4.
These commands have the same basic functions as in NTPv3 and
persistent association with a remote server or peer or reference
clock, and auxiliary commands that specify environmental variables
that control various related operations.
-@node Configuration
-@section Configuration
+@node Configuration Commands
+@section Configuration Commands
+
-Configuration
-Commands
The various modes are determined by the command keyword and the
type of the required IP address.
Addresses are classed by type as
In a few cases, including the reslist billboard generated
by ntpdc, IPv6 addresses are automatically generated.
IPv6 addresses can be identified by the presence of colons
-@quotedblleft{}\&:@quotedblright{}
+@quotedblleft{}:@quotedblright{}
in the address field.
IPv6 addresses can be used almost everywhere where
IPv4 addresses can be used,
which are always IPv4.
Note that in contexts where a host name is expected, a
-@code{-4} qualifier preceding
+@code{-4}
+qualifier preceding
the host name forces DNS resolution to the IPv4 namespace,
while a
-@code{-6} qualifier forces DNS resolution to the IPv6 namespace.
+@code{-6}
+qualifier forces DNS resolution to the IPv6 namespace.
See IPv6 references for the
equivalent classes for that address family.
-@table @samp
-@item Xo
-[@code{burst} ]
-[@code{iburst} ]
-[@code{version} @code{version} ]
-[@code{prefer} ]
-[@code{minpoll} @code{minpoll} ]
-[@code{maxpoll} @code{maxpoll} ]
-@item Xo
-[@code{key} @code{key} @code{\&|} @code{Cm} @code{autokey} ]
-[@code{burst} ]
-[@code{iburst} ]
-[@code{version} @code{version} ]
-[@code{prefer} ]
-[@code{minpoll} @code{minpoll} ]
-[@code{maxpoll} @code{maxpoll} ]
-@item Xo
-[@code{key} @code{key} @code{\&|} @code{Cm} @code{autokey} ]
-[@code{version} @code{version} ]
-[@code{prefer} ]
-[@code{minpoll} @code{minpoll} ]
-[@code{maxpoll} @code{maxpoll} ]
-@item Xo
-[@code{key} @code{key} @code{\&|} @code{Cm} @code{autokey} ]
-[@code{version} @code{version} ]
-[@code{prefer} ]
-[@code{minpoll} @code{minpoll} ]
-[@code{ttl} @code{ttl} ]
-@item Xo
-[@code{key} @code{key} @code{\&|} @code{Cm} @code{autokey} ]
-[@code{version} @code{version} ]
-[@code{prefer} ]
-[@code{minpoll} @code{minpoll} ]
-[@code{maxpoll} @code{maxpoll} ]
-[@code{ttl} @code{ttl} ]
+@table @asis
+
+@item @code{pool} @kbd{address}[@code{burst}][@code{iburst}][@code{version} @kbd{version}][@code{prefer}][@code{minpoll} @kbd{minpoll}][@code{maxpoll} @kbd{maxpoll}]
+@item @code{server} @kbd{address}[@code{key} @kbd{key} @kbd{|} @kbd{Cm} @kbd{autokey}][@code{burst}][@code{iburst}][@code{version} @kbd{version}][@code{prefer}][@code{minpoll} @kbd{minpoll}][@code{maxpoll} @kbd{maxpoll}]
+@item @code{peer} @kbd{address}[@code{key} @kbd{key} @kbd{|} @kbd{Cm} @kbd{autokey}][@code{version} @kbd{version}][@code{prefer}][@code{minpoll} @kbd{minpoll}][@code{maxpoll} @kbd{maxpoll}]
+@item @code{broadcast} @kbd{address}[@code{key} @kbd{key} @kbd{|} @kbd{Cm} @kbd{autokey}][@code{version} @kbd{version}][@code{prefer}][@code{minpoll} @kbd{minpoll}][@code{ttl} @kbd{ttl}]
+@item @code{manycastclient} @kbd{address}[@code{key} @kbd{key} @kbd{|} @kbd{Cm} @kbd{autokey}][@code{version} @kbd{version}][@code{prefer}][@code{minpoll} @kbd{minpoll}][@code{maxpoll} @kbd{maxpoll}][@code{ttl} @kbd{ttl}]
@end table
These five commands specify the time server name or address to
be used and the mode in which to operate.
The
-@code{address} can be
+@kbd{address}
+can be
either a DNS name or an IP address in dotted-quad notation.
Additional information on association behavior can be found in the
"Association Management"
(available as part of the HTML documentation
provided in
@file{/usr/share/doc/ntp}).
-@table @samp
-@item Ic
+@table @asis
+
+@item @code{pool}
For type s addresses, this command mobilizes a persistent
client mode association with a number of remote servers.
In this mode the local clock can synchronized to the
remote server, but the remote server can never be synchronized to
the local clock.
-@item Ic
+@item @code{server}
For type s and r addresses, this command mobilizes a persistent
client mode association with the specified remote server or local
radio clock.
remote server, but the remote server can never be synchronized to
the local clock.
This command should
-@emph{not}
+@emph{ not}
be used for type
b or m addresses.
-@item Ic
+@item @code{peer}
For type s addresses (only), this command mobilizes a
persistent symmetric-active mode association with the specified
remote peer.
the better source of time.
This command should NOT be used for type
b, m or r addresses.
-@item Ic
+@item @code{broadcast}
For type b and m addresses (only), this
command mobilizes a persistent broadcast mode association.
Multiple
subnet specified, but multicast messages go to all interfaces.
In broadcast mode the local server sends periodic broadcast
messages to a client population at the
-@code{address} specified, which is usually the broadcast address on (one of) the
+@kbd{address}
+specified, which is usually the broadcast address on (one of) the
local network(s) or a multicast address assigned to NTP.
The IANA
has assigned the multicast group address IPv4 224.0.1.1 and
Ordinarily, this
specification applies only to the local server operating as a
sender; for operation as a broadcast client, see the
-@code{broadcastclient} or
-@code{multicastclient} commands
+@code{broadcastclient}
+or
+@code{multicastclient}
+commands
below.
-@item Ic
+@item @code{manycastclient}
For type m addresses (only), this command mobilizes a
manycast client mode association for the multicast address
specified.
In this case a specific address must be supplied which
matches the address used on the
-@code{manycastserver} command for
+@code{manycastserver}
+command for
the designated manycast servers.
The NTP multicast address
224.0.1.1 assigned by the IANA should NOT be used, unless specific
these messages and causing a possibly massive implosion of replies
at the sender.
The
-@code{manycastserver} command specifies that the local server
+@code{manycastserver}
+command specifies that the local server
is to operate in client mode with the remote servers that are
discovered as the result of broadcast/multicast messages.
The
client broadcasts a request message to the group address associated
with the specified
-@code{address} and specifically enabled
+@kbd{address}
+and specifically enabled
servers respond to these messages.
The client selects the servers
providing the best time and continues as with the
-@code{server} command.
+@code{server}
+command.
The remaining servers are discarded as if never
heard.
@end table
Options:
-@table @samp
-@item Cm
+@table @asis
+
+@item @code{autokey}
All packets sent to and received from the server or peer are to
include authentication fields encrypted using the autokey scheme
described in
-@ref{Authentication}Authentication
-Options
-.
-@item Cm
+@ref{Authentication Options}.
+@item @code{burst}
when the server is reachable, send a burst of eight packets
instead of the usual one.
The packet spacing is normally 2 s;
additional time for a modem or ISDN call to complete.
This is designed to improve timekeeping quality
with the
-@code{server} command and s addresses.
-@item Cm
+@code{server}
+command and s addresses.
+@item @code{iburst}
When the server is unreachable, send a burst of eight packets
instead of the usual one.
The packet spacing is normally 2 s;
additional time for a modem or ISDN call to complete.
This is designed to speed the initial synchronization
acquisition with the
-@code{server} command and s addresses and when
+@code{server}
+command and s addresses and when
@code{ntpd(1ntpdmdoc)}
is started with the
-@code{-q} option.
-@item Cm
+@code{-q}
+option.
+@item @code{key} @kbd{key}
All packets sent to and received from the server or peer are to
include authentication fields encrypted using the specified
-@code{key} identifier with values from 1 to 65534, inclusive.
+@kbd{key}
+identifier with values from 1 to 65534, inclusive.
The
default is to include no encryption field.
-@item Cm
-@item Cm
+@item @code{minpoll} @kbd{minpoll}
+@item @code{maxpoll} @kbd{maxpoll}
These options specify the minimum and maximum poll intervals
for NTP messages, as a power of 2 in seconds
The maximum poll
interval defaults to 10 (1,024 s), but can be increased by the
-@code{maxpoll} option to an upper limit of 17 (36.4 h).
+@code{maxpoll}
+option to an upper limit of 17 (36.4 h).
The
minimum poll interval defaults to 6 (64 s), but can be decreased by
the
-@code{minpoll} option to a lower limit of 4 (16 s).
-@item Cm
+@code{minpoll}
+option to a lower limit of 4 (16 s).
+@item @code{noselect}
Marks the server as unused, except for display purposes.
The server is discarded by the selection algroithm.
-@item Cm
+@item @code{prefer}
Marks the server as preferred.
All other things being equal,
this host will be chosen for synchronization among a set of
provided in
@file{/usr/share/doc/ntp})
for further information.
-@item Cm
+@item @code{ttl} @kbd{ttl}
This option is used only with broadcast server and manycast
client modes.
It specifies the time-to-live
-@code{ttl} to
+@kbd{ttl}
+to
use on broadcast server and multicast server and the maximum
-@code{ttl} for the expanding ring search with manycast
+@kbd{ttl}
+for the expanding ring search with manycast
client packets.
Selection of the proper value, which defaults to
127, is something of a black art and should be coordinated with the
network administrator.
-@item Cm
+@item @code{version} @kbd{version}
Specifies the version number to be used for outgoing NTP
packets.
Versions 1-4 are the choices, with version 4 the
default.
@end table
-@node Auxiliary
-@section Auxiliary
+@node Auxiliary Commands
+@section Auxiliary Commands
+
+
+@table @asis
-Auxiliary
-Commands
-@table @samp
-@item Ic
+@item @code{broadcastclient}
This command enables reception of broadcast server messages to
any local interface (type b) address.
Upon receiving a message for
to avoid accidental or malicious disruption in this mode, both the
server and client should operate using symmetric-key or public-key
authentication as described in
-@ref{Authentication}Authentication
-Options
-.
-@item Ic
+@ref{Authentication Options}.
+@item @code{manycastserver} @kbd{address} @kbd{...}
This command enables reception of manycast client messages to
the multicast group address(es) (type m) specified.
At least one
accidental or malicious disruption in this mode, both the server
and client should operate using symmetric-key or public-key
authentication as described in
-@ref{Authentication}Authentication
-Options
-.
-@item Ic
+@ref{Authentication Options}.
+@item @code{multicastclient} @kbd{address} @kbd{...}
This command enables reception of multicast server messages to
the multicast group address(es) (type m) specified.
Upon receiving
in order to avoid accidental or malicious disruption in this mode,
both the server and client should operate using symmetric-key or
public-key authentication as described in
-@ref{Authentication}Authentication
-Options
-.
+@ref{Authentication Options}.
@end table
-@node Authentication
-@section Authentication
+@node Authentication Support
+@section Authentication Support
+
-Authentication
-Support
Authentication support allows the NTP client to verify that the
server is in fact known and trusted and not an intruder intending
accidentally or on purpose to masquerade as that server.
Authentication is configured separately for each association
using the
-@code{key} or
-@code{autokey} subcommand on the
-@code{peer}, @code{server}, @code{broadcast} and
-@code{manycastclient} configuration commands as described in
-@ref{Configuration}Configuration
-Options
+@code{key}
+or
+@code{autokey}
+subcommand on the
+@code{peer},
+@code{server},
+@code{broadcast}
+and
+@code{manycastclient}
+configuration commands as described in
+@ref{Configuration Options}
page.
The authentication
options described below specify the locations of the key files,
credentials and initialize the protocol
The
-@code{auth} flag controls whether new associations or
+@code{auth}
+flag controls whether new associations or
remote configuration commands require cryptographic authentication.
This flag can be set or reset by the
-@code{enable} and
-@code{disable} commands and also by remote
+@code{enable}
+and
+@code{disable}
+commands and also by remote
configuration commands sent by a
@code{ntpdc(1ntpdcmdoc)}
program running in
authenticated.
It should be understood
that operating with the
-@code{auth} flag disabled invites a significant vulnerability
+@code{auth}
+flag disabled invites a significant vulnerability
where a rogue hacker can
masquerade as a falseticker and seriously
disrupt system timekeeping.
An attractive alternative where multicast support is available
is manycast mode, in which clients periodically troll
for servers as described in the
-@ref{Automatic}Automatic
-NTP
-Configuration
-Options
+@ref{Automatic NTP Configuration Options}
page.
Either symmetric key or public key
cryptographic authentication can be used in this mode.
cryptography are summarized below;
further details are in the briefings, papers
and reports at the NTP project page linked from
-.Li
-http://www.ntp.org/
-.
-@node Symmetric-Key
-@section Symmetric-Key
-
-Symmetric-Key
-Cryptography
+@code{http://www.ntp.org/}.
+@node Symmetric-Key Cryptography
+@section Symmetric-Key Cryptography
+
+
The original RFC-1305 specification allows any one of possibly
65,534 keys, each distinguished by a 32-bit key identifier, to
authenticate an association.
When
@code{ntpd(1ntpdmdoc)}
is first started, it reads the key file specified in the
-@code{keys} configuration command and installs the keys
+@code{keys}
+configuration command and installs the keys
in the key cache.
However,
individual keys must be activated with the
-@code{trusted} command before use.
+@code{trusted}
+command before use.
This
allows, for instance, the installation of possibly
several batches of keys and
This also provides a revocation capability that can be used
if a key becomes compromised.
The
-@code{requestkey} command selects the key used as the password for the
+@code{requestkey}
+command selects the key used as the password for the
@code{ntpdc(1ntpdcmdoc)}
utility, while the
-@code{controlkey} command selects the key used as the password for the
+@code{controlkey}
+command selects the key used as the password for the
@code{ntpq(1ntpqmdoc)}
utility.
-@node Public
-@section Public
+@node Public Key Cryptography
+@section Public Key Cryptography
+
-Public
-Key
-Cryptography
NTPv4 supports the original NTPv3 symmetric key scheme
described in RFC-1305 and in addition the Autokey protocol,
which is based on public key cryptography.
in reverse order.
These schemes are described along with an executive summary,
current status, briefing slides and reading list on the
-@ref{Autonomous}Autonomous
-Authentication
+@ref{Autonomous Authentication}
page.
The specific cryptographic environment used by Autokey servers
There are several schemes
available in the OpenSSL software library, each identified
by a specific string such as
-@code{md5WithRSAEncryption}, which stands for the MD5 message digest with RSA
+@code{md5WithRSAEncryption},
+which stands for the MD5 message digest with RSA
encryption scheme.
The current NTP distribution supports
all the schemes in the OpenSSL library, including
engineered so that, even under anticipated failure conditions,
the NTP subnet will form such that every group host can find
a trail to at least one trusted host.
-@node Naming
-@section Naming
+@node Naming and Addressing
+@section Naming and Addressing
+
-Naming
-and
-Addressing
It is important to note that Autokey does not use DNS to
resolve addresses, since DNS can't be completely trusted
until the name servers have synchronized clocks.
@node Operation
@section Operation
-Operation
+
A specific combination of authentication scheme (none,
symmetric key, public key) and identity scheme is called
a cryptotype, although not all combinations are compatible.
of mobilization, either at configuration time or some time
later when a message of appropriate cryptotype arrives.
When mobilized by a
-@code{server} or
-@code{peer} configuration command and no
-@code{key} or
-@code{autokey} subcommands are present, the association is not
+@code{server}
+or
+@code{peer}
+configuration command and no
+@code{key}
+or
+@code{autokey}
+subcommands are present, the association is not
authenticated; if the
-@code{key} subcommand is present, the association is authenticated
+@code{key}
+subcommand is present, the association is authenticated
using the symmetric key ID specified; if the
-@code{autokey} subcommand is present, the association is authenticated
+@code{autokey}
+subcommand is present, the association is authenticated
using Autokey.
When multiple identity schemes are supported in the Autokey
If verification fails,
Bob sends Cathy a thing called a crypto-NAK, which tells her
something broke.
-She can see the evidence using the ntpq program.
+She can see the evidence using the
+@code{ntpq(1ntpqmdoc)}
+program.
Denise has rolled her own host key and certificate.
She also uses one of the identity schemes as Bob.
But, wise security policy might preclude some cryptotype
combinations; for instance, running an identity scheme
with one server and no authentication with another might not be wise.
-@node Key
-@section Key
+@node Key Management
+@section Key Management
+
-Key
-Management
The cryptographic values used by the Autokey protocol are
incorporated as a set of files generated by the
@code{ntp-keygen(1ntpkeygenmdoc)}
a subject key identifier or a issuer key identifier field;
however, an extended key usage field for a trusted host must
contain the value
-@code{trustRoot};. Other extension fields are ignored.
-@node Authentication
-@section Authentication
-
-Authentication
-Commands
-@table @samp
-@item Ic
+@code{trustRoot};.
+Other extension fields are ignored.
+@node Authentication Commands
+@section Authentication Commands
+
+
+@table @asis
+
+@item @code{autokey} [@kbd{logsec}]
Specifies the interval between regenerations of the session key
list used with the Autokey protocol.
Note that the size of the key
For poll intervals above the specified interval, a session key list
with a single entry will be regenerated for every message
sent.
-@item Ic
+@item @code{controlkey} @kbd{key}
Specifies the key identifier to use with the
@code{ntpq(1ntpqmdoc)}
utility, which uses the standard
protocol defined in RFC-1305.
The
-@code{key} argument is
+@kbd{key}
+argument is
the key identifier for a trusted key, where the value can be in the
range 1 to 65,534, inclusive.
-@item Xo
-[@code{cert} @code{file} ]
-[@code{leap} @code{file} ]
-[@code{randfile} @code{file} ]
-[@code{host} @code{file} ]
-[@code{sign} @code{file} ]
-[@code{gq} @code{file} ]
-[@code{gqpar} @code{file} ]
-[@code{iffpar} @code{file} ]
-[@code{mvpar} @code{file} ]
-[@code{pw} @code{password} ]
+@item @code{crypto}[@code{cert} @kbd{file}][@code{leap} @kbd{file}][@code{randfile} @kbd{file}][@code{host} @kbd{file}][@code{sign} @kbd{file}][@code{gq} @kbd{file}][@code{gqpar} @kbd{file}][@code{iffpar} @kbd{file}][@code{mvpar} @kbd{file}][@code{pw} @kbd{password}]
This command requires the OpenSSL library.
It activates public key
cryptography, selects the message digest and signature
Unless the complete path and name of the file are specified, the
location of a file is relative to the keys directory specified
in the
-@code{keysdir} command or default
+@code{keysdir}
+command or default
@file{/usr/local/etc}.
Following are the subcommands:
-@table @samp
-@item Cm
+@table @asis
+
+@item @code{cert} @kbd{file}
Specifies the location of the required host public certificate file.
This overrides the link
-@file{ntpkey_cert_}NsArhostname
+@file{ntpkey_cert_}@kbd{hostname}
in the keys directory.
-@item Cm
+@item @code{gqpar} @kbd{file}
Specifies the location of the optional GQ parameters file.
This
overrides the link
-@file{ntpkey_gq_}NsArhostname
+@file{ntpkey_gq_}@kbd{hostname}
in the keys directory.
-@item Cm
+@item @code{host} @kbd{file}
Specifies the location of the required host key file.
This overrides
the link
-@file{ntpkey_key_}NsArhostname
+@file{ntpkey_key_}@kbd{hostname}
in the keys directory.
-@item Cm
+@item @code{iffpar} @kbd{file}
Specifies the location of the optional IFF parameters file.This
overrides the link
-@file{ntpkey_iff_}NsArhostname
+@file{ntpkey_iff_}@kbd{hostname}
in the keys directory.
-@item Cm
+@item @code{leap} @kbd{file}
Specifies the location of the optional leapsecond file.
This overrides the link
@file{ntpkey_leap}
in the keys directory.
-@item Cm
+@item @code{mvpar} @kbd{file}
Specifies the location of the optional MV parameters file.
This
overrides the link
-@file{ntpkey_mv_}NsArhostname
+@file{ntpkey_mv_}@kbd{hostname}
in the keys directory.
-@item Cm
+@item @code{pw} @kbd{password}
Specifies the password to decrypt files containing private keys and
identity parameters.
This is required only if these files have been
encrypted.
-@item Cm
+@item @code{randfile} @kbd{file}
Specifies the location of the random seed file used by the OpenSSL
library.
The defaults are described in the main text above.
-@item Cm
+@item @code{sign} @kbd{file}
Specifies the location of the optional sign key file.
This overrides
the link
-@file{ntpkey_sign_}NsArhostname
+@file{ntpkey_sign_}@kbd{hostname}
in the keys directory.
If this file is
not found, the host key is also the sign key.
@end table
-.It
-Ic
-keys
-Ar
-keyfile
+@item @code{keys} @kbd{keyfile}
Specifies the complete path and location of the MD5 key file
containing the keys and key identifiers used by
@code{ntpd(1ntpdmdoc)},
@code{ntpdc(1ntpdcmdoc)}
when operating with symmetric key cryptography.
This is the same operation as the
-@code{-k} command line option.
-.It
-Ic
-keysdir
-Ar
-path
+@code{-k}
+command line option.
+@item @code{keysdir} @kbd{path}
This command specifies the default directory path for
cryptographic keys, parameters and certificates.
The default is
@file{/usr/local/etc/}.
-.It
-Ic
-requestkey
-Ar
-key
+@item @code{requestkey} @kbd{key}
Specifies the key identifier to use with the
@code{ntpdc(1ntpdcmdoc)}
utility program, which uses a
proprietary protocol specific to this implementation of
@code{ntpd(1ntpdmdoc)}.
The
-@code{key} argument is a key identifier
+@kbd{key}
+argument is a key identifier
for the trusted key, where the value can be in the range 1 to
65,534, inclusive.
-.It
-Ic
-revoke
-Ar
-logsec
+@item @code{revoke} @kbd{logsec}
Specifies the interval between re-randomization of certain
cryptographic values used by the Autokey scheme, as a power of 2 in
seconds.
For poll
intervals above the specified interval, the values will be updated
for every message sent.
-.It
-Ic
-trustedkey
-Ar
-key
-...
+@item @code{trustedkey} @kbd{key} @kbd{...}
Specifies the key identifiers which are trusted for the
purposes of authenticating peers with symmetric key cryptography,
as well as keys used by the
purpose, although different keys can be used with different
servers.
The
-@code{key} arguments are 32-bit unsigned
+@kbd{key}
+arguments are 32-bit unsigned
integers with values from 1 to 65,534.
+@end table
+@node Error Codes
+@section Error Codes
-@end multitable
-@node Error
-@section Error
-Error
-Codes
The following error codes are reported via the NTP control
and monitoring protocol trap mechanism.
-@table @samp
+@table @asis
+
@item 101
(bad field format or length)
The packet has invalid version, length or format.
(bad or missing identity)
The identity key is missing, corrupt or bogus.
@end table
-@node Monitoring
-@section Monitoring
+@node Monitoring Support
+@section Monitoring Support
+
-Monitoring
-Support
@code{ntpd(1ntpdmdoc)}
includes a comprehensive monitoring facility suitable
for continuous, long term recording of server and client
timekeeping performance.
See the
-@code{statistics} command below
+@code{statistics}
+command below
for a listing and example of each type of statistics currently
supported.
Statistic files are managed using file generation sets
@code{cron(8)}
jobs, the data can be
automatically summarized and archived for retrospective analysis.
-@node Monitoring
-@section Monitoring
+@node Monitoring Commands
+@section Monitoring Commands
-Monitoring
-Commands
-@table @samp
-@item Ic
+
+@table @asis
+
+@item @code{statistics} @kbd{name} @kbd{...}
Enables writing of statistics records.
Currently, four kinds of
-@code{name} statistics are supported.
-@table @samp
-@item Cm
+@kbd{name}
+statistics are supported.
+@table @asis
+
+@item @code{clockstats}
Enables recording of clock driver statistics information.
Each update
received from a clock driver appends a line of the following form to
the file generation set named
-@code{clockstats}: .Bd
--literal
+@code{clockstats}:
+@verbatim
49213 525.624 127.127.4.1 93 226 00:08:29.606 D
-.Ed
+@end verbatim
The first two fields show the date (Modified Julian Day) and time
(seconds and fraction past UTC midnight).
can be gathered and displayed as well.
See information specific to each
clock for further details.
-@item Cm
+@item @code{cryptostats}
This option requires the OpenSSL cryptographic software library.
It
enables recording of cryptographic public key protocol information.
Each message received by the protocol module appends a line of the
following form to the file generation set named
-@code{cryptostats}: .Bd
--literal
+@code{cryptostats}:
+@verbatim
49213 525.624 127.127.4.1 message
-.Ed
+@end verbatim
The first two fields show the date (Modified Julian Day) and time
(seconds and fraction past UTC midnight).
address in dotted-quad notation, The final message field includes the
message type and certain ancillary information.
See the
-@ref{Authentication}Authentication
-Options
+@ref{Authentication Options}
section for further information.
-@item Cm
+@item @code{loopstats}
Enables recording of loop filter statistics information.
Each
update of the local clock outputs a line of the following form to
the file generation set named
-@code{loopstats}: .Bd
--literal
+@code{loopstats}:
+@verbatim
50935 75440.031 0.000006019 13.778190 0.000351733 0.0133806
-.Ed
+@end verbatim
The first two fields show the date (Modified Julian Day) and
time (seconds and fraction past UTC midnight).
show time offset (seconds), frequency offset (parts per million -
PPM), RMS jitter (seconds), Allan deviation (PPM) and clock
discipline time constant.
-@item Cm
+@item @code{peerstats}
Enables recording of peer statistics information.
This includes
statistics records of all peers of a NTP server and of special
Each valid update appends a
line of the following form to the current element of a file
generation set named
-@code{peerstats}: .Bd
--literal
+@code{peerstats}:
+@verbatim
48773 10847.650 127.127.4.1 9714 -0.001605376 0.000000000 0.001424877 0.000958674
-.Ed
+@end verbatim
The first two fields show the date (Modified Julian Day) and
time (seconds and fraction past UTC midnight).
described in Appendix A of the NTP specification RFC 1305.
The final four fields show the offset,
delay, dispersion and RMS jitter, all in seconds.
-@item Cm
+@item @code{rawstats}
Enables recording of raw-timestamp statistics information.
This
includes statistics records of all peers of a NTP server and of
Each NTP message
received from a peer or clock driver appends a line of the
following form to the file generation set named
-@code{rawstats}: .Bd
--literal
+@code{rawstats}:
+@verbatim
50928 2132.543 128.4.1.1 128.4.1.20 3102453281.584327000 3102453281.58622800031 02453332.540806000 3102453332.541458000
-.Ed
+@end verbatim
The first two fields show the date (Modified Julian Day) and
time (seconds and fraction past UTC midnight).
The timestamp
values are as received and before processing by the various data
smoothing and mitigation algorithms.
-@item Cm
+@item @code{sysstats}
Enables recording of ntpd statistics counters on a periodic basis.
Each
hour a line of the following form is appended to the file generation
set named
-@code{sysstats}: .Bd
--literal
+@code{sysstats}:
+@verbatim
50928 2132.543 36000 81965 0 9546 56 71793 512 540 10 147
-.Ed
+@end verbatim
The first two fields show the date (Modified Julian Day) and time
(seconds and fraction past UTC midnight).
The remaining ten fields show
the statistics counter values accumulated since the last generated
line.
-@table @samp
-@item Time
+@table @asis
+
+@item Time since restart @code{36000}
Time in hours since the system was last rebooted.
-@item Packets
+@item Packets received @code{81965}
Total number of packets received.
-@item Packets
+@item Packets processed @code{0}
Number of packets received in response to previous packets sent
-@item Current
+@item Current version @code{9546}
Number of packets matching the current NTP version.
-@item Previous
+@item Previous version @code{56}
Number of packets matching the previous NTP version.
-@item Bad
+@item Bad version @code{71793}
Number of packets matching neither NTP version.
-@item Access
+@item Access denied @code{512}
Number of packets denied access for any reason.
-@item Bad
+@item Bad length or format @code{540}
Number of packets with invalid length, format or port number.
-@item Bad
+@item Bad authentication @code{10}
Number of packets not verified as authentic.
-@item Rate
+@item Rate exceeded @code{147}
Number of packets discarded due to rate limitation.
@end table
-.It
-Cm
-statsdir
-Ar
-directory_path
+@item @code{statsdir} @kbd{directory_path}
Indicates the full path of a directory where statistics files
should be created (see below).
This keyword allows
the (otherwise constant)
-@code{filegen} filename prefix to be modified for file generation sets, which
+@code{filegen}
+filename prefix to be modified for file generation sets, which
is useful for handling statistics logs.
-.It
-Cm
-filegen
-Ar
-name
-Xo
-[@code{file} @code{filename} ]
-[@code{type} @code{typename} ]
-[@code{link} | @code{nolink} ]
-[@code{enable} | @code{disable} ]
+@item @code{filegen} @kbd{name}
+[@code{file}@kbd{filename}]
+[@code{type}@kbd{typename}]
+[@code{link}|@code{nolink}]
+[@code{enable}|@code{disable}]
+
Configures setting of generation file set name.
Generation
file sets provide a means for handling files that are
Note that this command can be sent from the
@code{ntpdc(1ntpdcmdoc)}
program running at a remote location.
-@table @samp
-@item Cm
+@table @asis
+
+@item@code{name}
This is the type of the statistics records, as shown in the
-@code{statistics} command.
-@item Cm
+@code{statistics}
+command.
+@item@code{file}@kbd{filename}
This is the file name for the statistics records.
Filenames of set
members are built from three concatenated elements
-@code{Cm} @code{prefix}, @code{Cm} @code{filename} and
-@code{Cm} @code{suffix}: @table @samp
-@item Cm
+@kbd{Cm}@kbd{prefix},
+@kbd{Cm}@kbd{filename}
+and
+@kbd{Cm}@kbd{suffix}:
+@table @asis
+
+@item@code{prefix}
This is a constant filename path.
It is not subject to
modifications via the
-@code{filegen} option.
+@kbd{filegen}
+option.
It is defined by the
server, usually specified as a compile-time constant.
It may,
however, be configurable for individual file generation sets
via other commands.
For example, the prefix used with
-@code{loopstats} and
-@code{peerstats} generation can be configured using the
-@code{statsdir} option explained above.
-@item Cm
+@kbd{loopstats}
+and
+@kbd{peerstats}
+generation can be configured using the
+@kbd{statsdir}
+option explained above.
+@item@code{filename}
This string is directly concatenated to the prefix mentioned
above (no intervening
-@quoteleft{}@quoteright{}/).
+@quoteleft{}/).@quoteright{}
This can be modified using
the file argument to the
-@code{filegen} statement.
+@kbd{filegen}
+statement.
No
@file{..}
elements are
allowed in this component to prevent filenames referring to
parts outside the filesystem hierarchy denoted by
-@code{prefix}. @item Cm
+@kbd{prefix}.
+@item@code{suffix}
This part is reflects individual elements of a file set.
It is
generated according to the type of a file set.
@end table
-.It
-Cm
-type
-Ar
-typename
+@item@code{type}@kbd{typename}
A file generation set is characterized by its type.
The following
types are supported:
-@table @samp
-@item Cm
+@table @asis
+
+@item@code{none}
The file set is actually a single plain file.
-@item Cm
+@item@code{pid}
One element of file set is used per incarnation of a ntpd
server.
This type does not perform any changes to file set
@code{ntpd(1ntpdmdoc)}
server incarnations.
The set member filename is built by appending a
-@quoteleft{}\&.@quoteright{}
+@quoteleft{}.@quoteright{}
to concatenated
-@code{prefix} and
-@code{filename} strings, and
+@kbd{prefix}
+and
+@kbd{filename}
+strings, and
appending the decimal representation of the process ID of the
@code{ntpd(1ntpdmdoc)}
server process.
-@item Cm
+@item@code{day}
One file generation set element is created per day.
A day is
defined as the period between 00:00 and 24:00 UTC.
The file set
member suffix consists of a
-@quoteleft{}\&.@quoteright{}
+@quoteleft{}.@quoteright{}
and a day specification in
the form
-@code{YYYYMMdd}. @code{YYYY} is a 4-digit year number (e.g., 1992).
-@code{MM} is a two digit month number.
-@code{dd} is a two digit day number.
+@code{YYYYMMdd}.
+@code{YYYY}
+is a 4-digit year number (e.g., 1992).
+@code{MM}
+is a two digit month number.
+@code{dd}
+is a two digit day number.
Thus, all information written at 10 December 1992 would end up
in a file named
-@code{prefix} @code{filename} @code{Ns} @code{.19921210}. @item Cm
+@kbd{prefix}
+@kbd{filename}@kbd{Ns}@kbd{.19921210}.
+@item@code{week}
Any file set member contains data related to a certain week of
a year.
The term week is defined by computing day-of-year
Elements of such a file generation set are
distinguished by appending the following suffix to the file set
filename base: A dot, a 4-digit year number, the letter
-@code{W}, and a 2-digit week number.
+@code{W},
+and a 2-digit week number.
For example, information from January,
10th 1992 would end up in a file with suffix
-.No
-.
-Ns
-Ar
-1992W1
-.
-@item Cm
+No.@kbd{1992W1}.
+@item@code{month}
One generation file set element is generated per month.
The
file name suffix consists of a dot, a 4-digit year number, and
a 2-digit month.
-@item Cm
+@item@code{year}
One generation file element is generated per year.
The filename
suffix consists of a dot and a 4 digit year number.
-@item Cm
+@item@code{age}
This type of file generation sets changes to a new element of
the file set every 24 hours of server operation.
The filename
suffix consists of a dot, the letter
-@code{a}, and an 8-digit number.
+@code{a},
+and an 8-digit number.
This number is taken to be the number of seconds the server is
running at the start of the corresponding 24-hour period.
Information is only written to a file generation by specifying
-@code{enable}; output is prevented by specifying
-@code{disable}. @end table
-.It
-Cm
-link
-|
-nolink
+@code{enable};
+output is prevented by specifying
+@code{disable}.
+@end table
+@item@code{link}|@code{nolink}
It is convenient to be able to access the current element of a file
generation set by a fixed name.
This feature is enabled by
specifying
-@code{link} and disabled using
-@code{nolink}. If link is specified, a
+@code{link}
+and disabled using
+@code{nolink}.
+If link is specified, a
hard link from the current file set element to a file without
suffix is created.
When there is already a file with this name and
the number of links of this file is one, it is renamed appending a
dot, the letter
-@code{C}, and the pid of the ntpd server process.
+@code{C},
+and the pid of the ntpd server process.
When the
number of links is greater than one, the file is unlinked.
This
allows the current file to be accessed by a constant name.
-.It
-Cm
-enable
-\&|
-Cm
-disable
+@item@code{enable}@code{|}@code{Cm}@code{disable}
Enables or disables the recording function.
+@end table
+@end table
+@end table
+@node Access Control Support
+@section Access Control Support
-@end multitable
-
-@end multitable
-
-@end multitable
-@node Access
-@section Access
-Access
-Control
-Support
The
@code{ntpd(1ntpdmdoc)}
daemon implements a general purpose address/mask based restriction
last match found defining the restriction flags associated
with the entry.
Additional information and examples can be found in the
-"Notes on Configuring NTP and Setting up a NTP Subnet"
+"NotesonConfiguringNTPandSettingupaNTPSubnet"
page
(available as part of the HTML documentation
provided in
When a client or network is denied access
for an indefinate period, the only way at present to remove
the restrictions is by restarting the server.
-@node The
-@section The
+@node The Kiss-of-Death Packet
+@section The Kiss-of-Death Packet
+
-The
-Kiss-of-Death
-Packet
Ordinarily, packets denied service are simply dropped with no
further action except incrementing statistics counters.
Sometimes a
to zero and the reference identifier field set to a four-byte
ASCII code.
If the
-@code{noserve} or
-@code{notrust} flag of the matching restrict list entry is set,
+@code{noserve}
+or
+@code{notrust}
+flag of the matching restrict list entry is set,
the code is "DENY"; if the
-@code{limited} flag is set and the rate limit
+@code{limited}
+flag is set and the rate limit
is exceeded, the code is "RATE".
Finally, if a cryptographic violation occurs, the code is "CRYP".
This
happens automatically at the client when the association times out.
It will happen at the server only if the server operator cooperates.
-@node Access
-@section Access
-
-Access
-Control
-Commands
-@table @samp
-@item Xo
-[@code{average} @code{avg} ]
-[@code{minimum} @code{min} ]
-[@code{monitor} @code{prob} ]
+@node Access Control Commands
+@section Access Control Commands
+
+
+@table @asis
+
+@item@code{discard}[@code{average}@kbd{avg}][@code{minimum}@kbd{min}][@code{monitor}@kbd{prob}]
Set the parameters of the
-@code{limited} facility which protects the server from
+@code{limited}
+facility which protects the server from
client abuse.
The
-@code{average} subcommand specifies the minimum average packet
+@code{average}
+subcommand specifies the minimum average packet
spacing, while the
-@code{minimum} subcommand specifies the minimum packet spacing.
+@code{minimum}
+subcommand specifies the minimum packet spacing.
Packets that violate these minima are discarded
and a kiss-o'-death packet returned if enabled.
The default
minimum average and minimum are 5 and 2, respectively.
The monitor subcommand specifies the probability of discard
for packets that overflow the rate-control window.
-@item Xo
-[@code{mask} @code{mask} ]
-[@code{flag} @code{...} ]
+@item@code{restrict}@code{address}[@code{mask}@kbd{mask}][@kbd{flag}@kbd{...}]
The
-@code{address} argument expressed in
+@kbd{address}
+argument expressed in
dotted-quad form is the address of a host or network.
Alternatively, the
-@code{address} argument can be a valid host DNS name.
+@kbd{address}
+argument can be a valid host DNS name.
The
-@code{mask} argument expressed in dotted-quad form defaults to
-@code{255.255.255.255}, meaning that the
-@code{address} is treated as the address of an individual host.
+@kbd{mask}
+argument expressed in dotted-quad form defaults to
+@code{255.255.255.255},
+meaning that the
+@kbd{address}
+is treated as the address of an individual host.
A default entry (address
-@code{0.0.0.0}, mask
-@code{0.0.0.0}) is always included and is always the first entry in the list.
+@code{0.0.0.0},
+mask
+@code{0.0.0.0})
+is always included and is always the first entry in the list.
Note that text string
-@code{default}, with no mask option, may
+@code{default},
+with no mask option, may
be used to indicate the default entry.
In the current implementation,
-@code{flag} always
+@code{flag}
+always
restricts access, i.e., an entry with no flags indicates that free
access to the server is to be given.
The flags are not orthogonal,
reconfiguration of the server.
One or more of the following flags
may be specified:
-@table @samp
-@item Cm
+@table @asis
+
+@item@code{ignore}
Deny packets of all kinds, including
@code{ntpq(1ntpqmdoc)}
and
@code{ntpdc(1ntpdcmdoc)}
queries.
-@item Cm
+@item@code{kod}
If this flag is set when an access violation occurs, a kiss-o'-death
(KoD) packet is sent.
KoD packets are rate limited to no more than one
per second.
If another KoD packet occurs within one second after the
last one, the packet is dropped.
-@item Cm
+@item@code{limited}
Deny service if the packet spacing violates the lower limits specified
in the discard command.
A history of clients is kept using the
@code{ntpd(1ntpdmdoc)}.
Thus, monitoring is always active as
long as there is a restriction entry with the
-@code{limited} flag.
-@item Cm
+@code{limited}
+flag.
+@item@code{lowpriotrap}
Declare traps set by matching hosts to be low priority.
The
number of traps a server can maintain is limited (the current limit
This flag
modifies the assignment algorithm by allowing low priority traps to
be overridden by later requests for normal priority traps.
-@item Cm
+@item@code{nomodify}
Deny
@code{ntpq(1ntpqmdoc)}
and
server (i.e., run time reconfiguration).
Queries which return
information are permitted.
-@item Cm
+@item@code{noquery}
Deny
@code{ntpq(1ntpqmdoc)}
and
@code{ntpdc(1ntpdcmdoc)}
queries.
Time service is not affected.
-@item Cm
+@item@code{nopeer}
Deny packets which would result in mobilizing a new association.
This
includes broadcast and symmetric active packets when a configured
association does not exist.
-@item Cm
+@item@code{noserve}
Deny all packets except
@code{ntpq(1ntpqmdoc)}
and
@code{ntpdc(1ntpdcmdoc)}
queries.
-@item Cm
+@item@code{notrap}
Decline to provide mode 6 control message trap service to matching
hosts.
The trap service is a subsystem of the ntpdq control message
protocol which is intended for use by remote event logging programs.
-@item Cm
+@item@code{notrust}
Deny service unless the packet is cryptographically authenticated.
-@item Cm
+@item@code{ntpport}
This is actually a match algorithm modifier, rather than a
restriction flag.
Its presence causes the restriction entry to be
matched only if the source port in the packet is the standard NTP
UDP port (123).
Both
-@code{ntpport} and
-@code{non-ntpport} may
+@code{ntpport}
+and
+@code{non-ntpport}
+may
be specified.
The
-@code{ntpport} is considered more specific and
+@code{ntpport}
+is considered more specific and
is sorted later in the list.
-@item Cm
+@item@code{version}
Deny packets that do not match the current NTP version.
@end table
otherwise unconfigured; no flags are associated
with the default entry (i.e., everything besides your own
NTP server is unrestricted).
+@end table
+@node Automatic NTP Configuration Options
+@section Automatic NTP Configuration Options
-@end multitable
-@node Automatic
-@section Automatic
-Automatic
-NTP
-Configuration
-Options
@node Manycasting
@section Manycasting
-Manycasting
+
Manycasting is a automatic discovery and configuration paradigm
new to NTPv4.
It is intended as a means for a multicast client
large key sizes.
It is implemented using the Autokey protocol and
the OpenSSL cryptographic library available from
-.Li
-http://www.openssl.org/
-.
+@code{http://www.openssl.org/}.
The library can also be used with other NTPv4 modes
as well and is highly recommended, especially for broadcast modes.
A persistent manycast client association is configured
using the manycastclient command, which is similar to the
server command but with a multicast (IPv4 class
-@code{D} or IPv6 prefix
-@code{FF}) group address.
+@code{D}
+or IPv6 prefix
+@code{FF})
+group address.
The IANA has designated IPv4 address 224.1.1.1
and IPv6 address FF05::101 (site local) for NTP.
When more servers are needed, it broadcasts manycast
for a future ephemeral unicast client/server association.
Manycast servers configured with the
-@code{manycastserver} command listen on the specified group address for manycast
+@code{manycastserver}
+command listen on the specified group address for manycast
client messages.
Note the distinction between manycast client,
which actively broadcasts messages, and manycast server,
and the effects of implosion due to near-simultaneous
arrival of manycast server messages.
The strategy is determined by the
-@code{manycastclient}, @code{tos} and
-@code{ttl} configuration commands.
+@code{manycastclient},
+@code{tos}
+and
+@code{ttl}
+configuration commands.
The manycast poll interval is
normally eight times the system poll interval,
which starts out at the
-@code{minpoll} value specified in the
-@code{manycastclient}, command and, under normal circumstances, increments to the
-@code{maxpolll} value specified in this command.
+@code{minpoll}
+value specified in the
+@code{manycastclient},
+command and, under normal circumstances, increments to the
+@code{maxpolll}
+value specified in this command.
Initially, the TTL is
set at the minimum hops specified by the ttl command.
At each retransmission the TTL is increased until reaching
The quality and reliability of the suite of associations
discovered by the manycast client is determined by the NTP
mitigation algorithms and the
-@code{minclock} and
-@code{minsane} values specified in the
-@code{tos} configuration command.
+@code{minclock}
+and
+@code{minsane}
+values specified in the
+@code{tos}
+configuration command.
At least
-@code{minsane} candidate servers must be available and the mitigation
+@code{minsane}
+candidate servers must be available and the mitigation
algorithms produce at least
-@code{minclock} survivors in order to synchronize the clock.
+@code{minclock}
+survivors in order to synchronize the clock.
Byzantine agreement principles require at least four
candidates in order to correctly discard a single falseticker.
For legacy purposes,
-@code{minsane} defaults to 1 and
-@code{minclock} defaults to 3.
+@code{minsane}
+defaults to 1 and
+@code{minclock}
+defaults to 3.
For manycast service
-@code{minsane} should be explicitly set to 4, assuming at least that
+@code{minsane}
+should be explicitly set to 4, assuming at least that
number of servers are available.
If at least
-@code{minclock} servers are found, the manycast poll interval is immediately
+@code{minclock}
+servers are found, the manycast poll interval is immediately
set to eight times
-@code{maxpoll}. If less than
-@code{minclock} servers are found when the TTL has reached the maximum hops,
+@code{maxpoll}.
+If less than
+@code{minclock}
+servers are found when the TTL has reached the maximum hops,
the manycast poll interval is doubled.
For each transmission
after that, the poll interval is doubled again until
reaching the maximum of eight times
-@code{maxpoll}. Further transmissions use the same poll interval and
+@code{maxpoll}.
+Further transmissions use the same poll interval and
TTL values.
Note that while all this is going on,
each client/server association found is operating normally
in the case of IPv6, the link/site scope prefix.
By default, the increment for TTL hops is 32 starting
from 31; however, the
-@code{ttl} configuration command can be
+@code{ttl}
+configuration command can be
used to modify the values to match the scope rules.
It is often useful to narrow the range of acceptable
in TTL range, which is probably not the most common
objective in large networks.
The
-@code{tos} command can be used to modify this behavior.
+@code{tos}
+command can be used to modify this behavior.
Servers with stratum below
-@code{floor} or above
-@code{ceiling} specified in the
-@code{tos} command are strongly discouraged during the selection
+@code{floor}
+or above
+@code{ceiling}
+specified in the
+@code{tos}
+command are strongly discouraged during the selection
process; however, these servers may be temporally
accepted if the number of servers within TTL range is
less than
-@code{minclock}.
+@code{minclock}.
+
The above actions occur for each manycast client message,
which repeats at the designated poll interval.
However, once the ephemeral client association is mobilized,
since that would result in a duplicate association.
If during a poll interval the number of client associations
falls below
-@code{minclock}, all manycast client prototype associations are reset
+@code{minclock},
+all manycast client prototype associations are reset
to the initial poll interval and TTL hops and operation
resumes from the beginning.
It is important to avoid
The result could well be an implosion, either minor or major,
depending on the number of servers in range.
The recommended value for
-@code{maxpoll} is 12 (4,096 s).
+@code{maxpoll}
+is 12 (4,096 s).
It is possible and frequently useful to configure a host
as both manycast client and manycast server.
dependent clients.
With two exceptions, all servers
and clients have identical configuration files including both
-@code{multicastclient} and
-@code{multicastserver} commands using, for instance, multicast group address
+@code{multicastclient}
+and
+@code{multicastserver}
+commands using, for instance, multicast group address
239.1.1.1.
The only exception is that each primary server
configuration file must include commands for the primary
The remaining configuration files for all secondary
servers and clients have the same contents, except for the
-@code{tos} command, which is specific for each stratum level.
+@code{tos}
+command, which is specific for each stratum level.
For stratum 1 and stratum 2 servers, that command is
not necessary.
For stratum 3 and above servers the
-@code{floor} value is set to the intended stratum number.
+@code{floor}
+value is set to the intended stratum number.
Thus, all stratum 3 configuration files are identical,
all stratum 4 files are identical and so forth.
@code{ntpdate(8)}
or
@code{ntpd(1ntpdmdoc)}
-@code{-q} as a cron job.
+@code{-q}
+as a cron job.
In either case the servers must be
configured in advance and the program fails if none are
available when the cron job runs.
A really slick
application of manycast is with
@code{ntpd(1ntpdmdoc)}
-@code{-q}. The program wakes up, scans the local landscape looking
+@code{-q}.
+The program wakes up, scans the local landscape looking
for the usual suspects, selects the best from among
the rascals, sets the clock and then departs.
Servers do not have to be configured in advance and
all clients throughout the network can have the same
configuration file.
-@node Manycast
-@section Manycast
+@node Manycast Interactions with Autokey
+@section Manycast Interactions with Autokey
+
-Manycast
-Interactions
-with
-Autokey
Each time a manycast client sends a client mode packet
to a multicast group address, all manycast servers
in scope generate a reply including the host name
scheme starts all over from the beginning and
the expanding ring shrinks to the minimum and increments
from there while collecting all servers in scope.
-@node Manycast
-@section Manycast
-
-Manycast
-Options
-@table @samp
-@item Xo
-.Oo
-@code{ceiling} @code{ceiling} | @code{cohort}{ @code{0} | @code{1}} | @code{floor} @code{floor} | @code{minclock} @code{minclock} | @code{minsane} @code{minsane} .Oc
+@node Manycast Options
+@section Manycast Options
+
+
+@table @asis
+
+@item@code{tos}Oo@code{ceiling}@kbd{ceiling}|@code{cohort}{@code{0}|@code{1}}|@code{floor}@kbd{floor}|@code{minclock}@kbd{minclock}|@code{minsane}@kbd{minsane}Oc
This command affects the clock selection and clustering
algorithms.
It can be used to select the quality and
and is most useful in manycast mode.
The variables operate
as follows:
-@table @samp
-@item Cm
+@table @asis
+
+@item@code{ceiling}@kbd{ceiling}
Peers with strata above
-@code{ceiling} will be discarded if there are at least
-@code{minclock} peers remaining.
+@code{ceiling}
+will be discarded if there are at least
+@code{minclock}
+peers remaining.
This value defaults to 15, but can be changed
to any number from 1 to 15.
-@item Cm
+@item@code{cohort}@code{Bro}@code{0}|@code{1}@code{Brc}
This is a binary flag which enables (0) or disables (1)
manycast server replies to manycast clients with the same
stratum level.
large numbers of clients with the same stratum level
are present.
The default is to enable these replies.
-@item Cm
+@item@code{floor}@kbd{floor}
Peers with strata below
-@code{floor} will be discarded if there are at least
-@code{minclock} peers remaining.
+@code{floor}
+will be discarded if there are at least
+@code{minclock}
+peers remaining.
This value defaults to 1, but can be changed
to any number from 1 to 15.
-@item Cm
+@item@code{minclock}@kbd{minclock}
The clustering algorithm repeatedly casts out outlyer
associations until no more than
-@code{minclock} associations remain.
+@code{minclock}
+associations remain.
This value defaults to 3,
but can be changed to any number from 1 to the number of
configured sources.
-@item Cm
+@item@code{minsane}@kbd{minsane}
This is the minimum number of candidates available
to the clock selection algorithm in order to produce
one or more truechimers for the clustering algorithm.
for legacy purposes.
However, according to principles of
Byzantine agreement,
-@code{minsane} should be at least 4 in order to detect and discard
+@code{minsane}
+should be at least 4 in order to detect and discard
a single falseticker.
@end table
-.It
-Cm
-ttl
-Ar
-hop
-...
+@item@code{ttl}@kbd{hop}@kbd{...}
This command specifies a list of TTL values in increasing
order, up to 8 values can be specified.
In manycast mode these values are used in turn
in an expanding-ring search.
The default is eight
multiples of 32 starting at 31.
+@end table
+@node Reference Clock Support
+@section Reference Clock Support
-@end multitable
-@node Reference
-@section Reference
-Reference
-Clock
-Support
The NTP Version 4 daemon supports some three dozen different radio,
satellite and modem reference clocks plus a special pseudo-clock
used for backup or when no other clock source is available.
Detailed descriptions of individual device drivers and options can
be found in the
-"Reference Clock Drivers"
+"ReferenceClockDrivers"
page
(available as part of the HTML documentation
provided in
@file{/usr/share/doc/ntp}).
Additional information can be found in the pages linked
there, including the
-"Debugging Hints for Reference Clock Drivers"
+"DebuggingHintsforReferenceClockDrivers"
and
-"How To Write a Reference Clock Driver"
+"HowToWriteaReferenceClockDriver"
pages
(available as part of the HTML documentation
provided in
@file{/usr/share/doc/ntp}).
In addition, support for a PPS
signal is available as described in the
-"Pulse-per-second (PPS) Signal Interfacing"
+"Pulse-per-second(PPS)SignalInterfacing"
page
(available as part of the HTML documentation
provided in
significantly improve the accuracy using the driver.
These are
described in the
-"Line Disciplines and Streams Drivers"
+"LineDisciplinesandStreamsDrivers"
page
(available as part of the HTML documentation
provided in
correct but invalid IP address, in order to distinguish them from
normal NTP peers.
Reference clock addresses are of the form
-.Sm
-off
-.Li
-127.127.
-Ar
-t
-.
-Ar
-u
-,
-.Sm
-on
+
+@code{127.127.}@kbd{t}.@kbd{u},
+
where
-@code{t} is an integer
+@kbd{t}
+is an integer
denoting the clock type and
-@code{u} indicates the unit
+@kbd{u}
+indicates the unit
number in the range 0-3.
While it may seem overkill, it is in fact
sometimes useful to configure multiple reference clocks of the same
type, in which case the unit numbers must be unique.
The
-@code{server} command is used to configure a reference
+@code{server}
+command is used to configure a reference
clock, where the
-@code{address} argument in that command
+@kbd{address}
+argument in that command
is the clock address.
The
-@code{key}, @code{version} and
-@code{ttl} options are not used for reference clock support.
+@code{key},
+@code{version}
+and
+@code{ttl}
+options are not used for reference clock support.
The
-@code{mode} option is added for reference clock support, as
+@code{mode}
+option is added for reference clock support, as
described below.
The
-@code{prefer} option can be useful to
+@code{prefer}
+option can be useful to
persuade the server to cherish a reference clock with somewhat more
enthusiasm than other reference clocks or peers.
Further
@file{/usr/share/doc/ntp})
page.
The
-@code{minpoll} and
-@code{maxpoll} options have
+@code{minpoll}
+and
+@code{maxpoll}
+options have
meaning only for selected clock drivers.
See the individual clock
driver document pages for additional information.
The
-@code{fudge} command is used to provide additional
+@code{fudge}
+command is used to provide additional
information for individual clock drivers and normally follows
immediately after the
-@code{server} command.
+@code{server}
+command.
The
-@code{address} argument specifies the clock address.
+@kbd{address}
+argument specifies the clock address.
The
-@code{refid} and
-@code{stratum} options can be used to
+@code{refid}
+and
+@code{stratum}
+options can be used to
override the defaults for the device.
There are two optional
device-dependent time offsets and four flags that can be included
in the
-@code{fudge} command as well.
+@code{fudge}
+command as well.
The stratum number of a reference clock is by default zero.
Since the
In order to provide engineered backups, it is often useful to
specify the reference clock stratum as greater than zero.
The
-@code{stratum} option is used for this purpose.
+@code{stratum}
+option is used for this purpose.
Also, in cases
involving both a reference clock and a pulse-per-second (PPS)
discipline signal, it is useful to specify the reference clock
identifier as other than the default, depending on the driver.
The
-@code{refid} option is used for this purpose.
+@code{refid}
+option is used for this purpose.
Except where noted,
these options apply to all clock drivers.
-@node Reference
-@section Reference
-
-Reference
-Clock
-Commands
-@table @samp
-@item Xo
-.Sm
-off
-.Li
-127.127.
-Ar
-t
-.
-Ar
-u
-.Sm
-on
-[@code{prefer} ]
-[@code{mode} @code{int} ]
-[@code{minpoll} @code{int} ]
-[@code{maxpoll} @code{int} ]
+@node Reference Clock Commands
+@section Reference Clock Commands
+
+
+@table @asis
+
+@item @code{server}@code{127.127.}@kbd{t}.@kbd{u}[@code{prefer}][@code{mode} @kbd{int}][@code{minpoll} @kbd{int}][@code{maxpoll} @kbd{int}]
This command can be used to configure reference clocks in
special ways.
The options are interpreted as follows:
-@table @samp
-@item Cm
+@table @asis
+
+@item @code{prefer}
Marks the reference clock as preferred.
All other things being
equal, this host will be chosen for synchronization among a set of
provided in
@file{/usr/share/doc/ntp})
for further information.
-@item Cm
+@item @code{mode} @kbd{int}
Specifies a mode number which is interpreted in a
device-specific fashion.
For instance, it selects a dialing
protocol in the ACTS driver and a device subtype in the
parse
drivers.
-@item Cm
-@item Cm
+@item @code{minpoll} @kbd{int}
+@item @code{maxpoll} @kbd{int}
These options specify the minimum and maximum polling interval
for reference clock messages, as a power of 2 in seconds
For
most directly connected reference clocks, both
-@code{minpoll} and
-@code{maxpoll} default to 6 (64 s).
+@code{minpoll}
+and
+@code{maxpoll}
+default to 6 (64 s).
For modem reference clocks,
-@code{minpoll} defaults to 10 (17.1 m) and
-@code{maxpoll} defaults to 14 (4.5 h).
+@code{minpoll}
+defaults to 10 (17.1 m) and
+@code{maxpoll}
+defaults to 14 (4.5 h).
The allowable range is 4 (16 s) to 17 (36.4 h) inclusive.
@end table
-.It
-Xo
-Ic
-fudge
-.Sm
-off
-.Li
-127.127.
-Ar
-t
-.
-Ar
-u
-.Sm
-on
-[@code{time1} @code{sec} ]
-[@code{time2} @code{sec} ]
-[@code{stratum} @code{int} ]
-[@code{refid} @code{string} ]
-[@code{mode} @code{int} ]
-[@code{flag1} @code{Cm} @code{0} @code{\&|} @code{Cm} @code{1} ]
-[@code{flag2} @code{Cm} @code{0} @code{\&|} @code{Cm} @code{1} ]
-[@code{flag3} @code{Cm} @code{0} @code{\&|} @code{Cm} @code{1} ]
-[@code{flag4} @code{Cm} @code{0} @code{\&|} @code{Cm} @code{1} ]
+@item @code{fudge}@code{127.127.}@kbd{t}.@kbd{u}[@code{time1} @kbd{sec}][@code{time2} @kbd{sec}][@code{stratum} @kbd{int}][@code{refid} @kbd{string}][@code{mode} @kbd{int}][@code{flag1} @code{Cm} @code{0} @code{|} @code{Cm} @code{1}][@code{flag2} @code{Cm} @code{0} @code{|} @code{Cm} @code{1}][@code{flag3} @code{Cm} @code{0} @code{|} @code{Cm} @code{1}][@code{flag4} @code{Cm} @code{0} @code{|} @code{Cm} @code{1}]
This command can be used to configure reference clocks in
special ways.
It must immediately follow the
-@code{server} command which configures the driver.
+@code{server}
+command which configures the driver.
Note that the same capability
is possible at run time using the
@code{ntpdc(1ntpdcmdoc)}
program.
The options are interpreted as
follows:
-@table @samp
-@item Cm
+@table @asis
+
+@item @code{time1} @kbd{sec}
Specifies a constant to be added to the time offset produced by
the driver, a fixed-point decimal number in seconds.
This is used
radio clock or PPS signal is supported, a special calibration
feature is available.
It takes the form of an argument to the
-@code{enable} command described in
-@ref{Miscellaneous}Miscellaneous
-Options
+@code{enable}
+command described in
+@ref{Miscellaneous Options}
page and operates as described in the
"Reference Clock Drivers"
page
(available as part of the HTML documentation
provided in
@file{/usr/share/doc/ntp}).
-@item Cm
+@item @code{time2} @kbd{secs}
Specifies a fixed-point decimal number in seconds, which is
interpreted in a driver-dependent way.
See the descriptions of
(available as part of the HTML documentation
provided in
@file{/usr/share/doc/ntp}).
-@item Cm
+@item @code{stratum} @kbd{int}
Specifies the stratum number assigned to the driver, an integer
between 0 and 15.
This number overrides the default stratum number
ordinarily assigned by the driver itself, usually zero.
-@item Cm
+@item @code{refid} @kbd{string}
Specifies an ASCII string of from one to four characters which
defines the reference identifier used by the driver.
This string
overrides the default identifier ordinarily assigned by the driver
itself.
-@item Cm
+@item @code{mode} @kbd{int}
Specifies a mode number which is interpreted in a
device-specific fashion.
For instance, it selects a dialing
protocol in the ACTS driver and a device subtype in the
parse
drivers.
-@item Cm
-@item Cm
-@item Cm
-@item Cm
+@item @code{flag1} @code{Cm} @code{0} @code{|} @code{Cm} @code{1}
+@item @code{flag2} @code{Cm} @code{0} @code{|} @code{Cm} @code{1}
+@item @code{flag3} @code{Cm} @code{0} @code{|} @code{Cm} @code{1}
+@item @code{flag4} @code{Cm} @code{0} @code{|} @code{Cm} @code{1}
These four flags are used for customizing the clock driver.
The
interpretation of these values, and whether they are used at all,
is a function of the particular clock driver.
However, by
convention
-@code{flag4} is used to enable recording monitoring
+@code{flag4}
+is used to enable recording monitoring
data to the
-@code{clockstats} file configured with the
-@code{filegen} command.
+@code{clockstats}
+file configured with the
+@code{filegen}
+command.
Further information on the
-@code{filegen} command can be found in
-@ref{Monitoring}Monitoring
-Options
-.
+@code{filegen}
+command can be found in
+@ref{Monitoring Options}.
+@end table
@end table
+@node Miscellaneous Options
+@section Miscellaneous Options
-@end multitable
-@node Miscellaneous
-@section Miscellaneous
-Miscellaneous
-Options
-@table @samp
-@item Ic
+@table @asis
+
+@item @code{broadcastdelay} @kbd{seconds}
The broadcast and multicast modes require a special calibration
to determine the network delay between the local and remote
servers.
number between 0.003 and 0.007 seconds is appropriate.
The default
when this command is not used is 0.004 seconds.
-@item Ic
+@item @code{calldelay} @kbd{delay}
This option controls the delay in seconds between the first and second
packets sent in burst or iburst mode to allow additional time for a modem
or ISDN call to complete.
-@item Ic
+@item @code{driftfile} @kbd{driftfile}
This command specifies the complete path and name of the file used to
record the frequency of the local clock oscillator.
This is the same
operation as the
-@code{-f} command line option.
+@code{-f}
+command line option.
If the file exists, it is read at
startup in order to set the initial frequency and then updated once per
hour with the current frequency computed by the daemon.
must have write permission for the directory the
drift file is located in, and that file system links, symbolic or
otherwise, should be avoided.
-@item Xo
-.Oo
-@code{auth} | @code{Cm} @code{bclient} | @code{calibrate} | @code{Cm} @code{kernel} | @code{monitor} | @code{Cm} @code{ntp} | @code{pps} | @code{Cm} @code{stats} .Oc
-@item Xo
-.Oo
-@code{auth} | @code{Cm} @code{bclient} | @code{calibrate} | @code{Cm} @code{kernel} | @code{monitor} | @code{Cm} @code{ntp} | @code{pps} | @code{Cm} @code{stats} .Oc
+@item @code{enable}Oo@code{auth} | @code{Cm} @code{bclient} |@code{calibrate} | @code{Cm} @code{kernel} |@code{monitor} | @code{Cm} @code{ntp} |@code{pps} | @code{Cm} @code{stats}Oc
+@item @code{disable}Oo@code{auth} | @code{Cm} @code{bclient} |@code{calibrate} | @code{Cm} @code{kernel} |@code{monitor} | @code{Cm} @code{ntp} |@code{pps} | @code{Cm} @code{stats}Oc
Provides a way to enable or disable various server options.
Flags not mentioned are unaffected.
Note that all of these flags
can be controlled remotely using the
@code{ntpdc(1ntpdcmdoc)}
utility program.
-@table @samp
-@item Cm
+@table @asis
+
+@item @code{auth}
Enables the server to synchronize with unconfigured peers only if the
peer has been correctly authenticated using either public key or
private key cryptography.
The default for this flag is
-@code{enable}. @item Cm
+@code{enable}.
+@item @code{bclient}
Enables the server to listen for a message from a broadcast or
multicast server, as in the
-@code{multicastclient} command with default
+@code{multicastclient}
+command with default
address.
The default for this flag is
-@code{disable}. @item Cm
+@code{disable}.
+@item @code{calibrate}
Enables the calibrate feature for reference clocks.
The default for
this flag is
-@code{disable}. @item Cm
+@code{disable}.
+@item @code{kernel}
Enables the kernel time discipline, if available.
The default for this
flag is
-@code{enable} if support is available, otherwise
-@code{disable}. @item Cm
+@code{enable}
+if support is available, otherwise
+@code{disable}.
+@item @code{monitor}
Enables the monitoring facility.
See the
@code{ntpdc(1ntpdcmdoc)}
program
and the
-@code{monlist} command or further information.
+@code{monlist}
+command or further information.
The
default for this flag is
-@code{enable}. @item Cm
+@code{enable}.
+@item @code{ntp}
Enables time and frequency discipline.
In effect, this switch opens and
closes the feedback loop, which is useful for testing.
The default for
this flag is
-@code{enable}. @item Cm
+@code{enable}.
+@item @code{pps}
Enables the pulse-per-second (PPS) signal when frequency and time is
disciplined by the precision time kernel modifications.
See the
@file{/usr/share/doc/ntp})
page for further information.
The default for this flag is
-@code{disable}. @item Cm
+@code{disable}.
+@item @code{stats}
Enables the statistics facility.
See the
-@ref{Monitoring}Monitoring
-Options
+@ref{Monitoring Options}
section for further information.
The default for this flag is
-@code{disable}. @end table
-.It
-Ic
-includefile
-Ar
-includefile
+@code{disable}.
+@end table
+@item @code{includefile} @kbd{includefile}
This command allows additional configuration commands
to be included from a separate file.
Include files may
@code{ntpd(1ntpdmdoc)}
on multiple hosts, with (mostly) common options (e.g., a
restriction list).
-.It
-Ic
-logconfig
-Ar
-configkeyword
+@item @code{logconfig} @kbd{configkeyword}
This command controls the amount and type of output written to
the system
@code{syslog(3)}
facility or the alternate
-@code{logfile} log file.
+@code{logfile}
+log file.
By default, all output is turned on.
All
-@code{configkeyword} keywords can be prefixed with
-@quoteleft{}@quoteright{}=,
-@quoteleft{}@quoteright{}+
+@kbd{configkeyword}
+keywords can be prefixed with
+@quoteleft{}=,@quoteright{}
+@quoteleft{}+@quoteright{}
and
-@quoteleft{}@quoteright{}-,
+@quoteleft{}-,@quoteright{}
where
-@quoteleft{}@quoteright{}=
+@quoteleft{}=@quoteright{}
sets the
@code{syslog(3)}
priority mask,
-@quoteleft{}@quoteright{}+
+@quoteleft{}+@quoteright{}
adds and
-@quoteleft{}@quoteright{}-
+@quoteleft{}-@quoteright{}
removes
messages.
@code{syslog(3)}
messages can be controlled in four
classes
-.Po
-@code{clock}, @code{peer}, @code{sys} and
-@code{sync} .Pc
-.
+Po
+@code{clock},
+@code{peer},
+@code{sys}
+and
+@code{sync}
+Pc.
Within these classes four types of messages can be
controlled: informational messages
-.Po
-@code{info} .Pc
-,
+Po
+@code{info}
+Pc,
event messages
-.Po
-@code{events} .Pc
-,
+Po
+@code{events}
+Pc,
statistics messages
-.Po
-@code{statistics} .Pc
+Po
+@code{statistics}
+Pc
and
status messages
-.Po
-@code{status} .Pc
-.
+Po
+@code{status}
+Pc.
Configuration keywords are formed by concatenating the message class with
the event class.
The
-@code{all} prefix can be used instead of a message class.
+@code{all}
+prefix can be used instead of a message class.
A
message class may also be followed by the
-@code{all} keyword to enable/disable all
+@code{all}
+keyword to enable/disable all
messages of the respective message class.Thus, a minimal log configuration
could look like this:
-.Bd
--literal
+@verbatim
logconfig =syncstatus +sysevents
-.Ed
+@end verbatim
This would just list the synchronizations state of
@code{ntpd(1ntpdmdoc)}
and the major system events.
For a simple reference server, the
following minimum message configuration could be useful:
-.Bd
--literal
+@verbatim
logconfig =syncall +clockall
-.Ed
+@end verbatim
This configuration will list all clock information and
synchronization information.
All other events and messages about
peers, system events and so on is suppressed.
-.It
-Ic
-logfile
-Ar
-logfile
+@item @code{logfile} @kbd{logfile}
This command specifies the location of an alternate log file to
be used instead of the default system
@code{syslog(3)}
facility.
This is the same operation as the -l command line option.
-.It
-Ic
-setvar
-Ar
-variable
-Op
-Cm
-default
+@item @code{setvar} @kbd{variable} [@code{default}]
This command adds an additional system variable.
These
variables can be used to distribute additional information such as
the access policy.
If the variable of the form
-.Sm
-off
-.Va
-name
-=
-Ar
-value
-.Sm
-on
+
+Vaname=@kbd{value}
+
is followed by the
-@code{default} keyword, the
+@code{default}
+keyword, the
variable will be listed as part of the default system variables
-.Po
+Po
@code{ntpq(1ntpqmdoc)}
-@code{rv} command
-.Pc
-)
-.
+@code{rv}
+command
+Pc).
These additional variables serve
informational purposes only.
They are not related to the protocol
other that they can be listed.
The known protocol variables will
always override any variables defined via the
-@code{setvar} mechanism.
+@code{setvar}
+mechanism.
There are three special variables that contain the names
of all variable of the same group.
The
-.Va
-sys_var_list
+Va sys_var_list
holds
the names of all system variables.
The
-.Va
-peer_var_list
+Va peer_var_list
holds
the names of all peer variables and the
-.Va
-clock_var_list
+Va clock_var_list
holds the names of the reference clock variables.
-.It
-Xo
-Ic
-tinker
-.Oo
-@code{allan} @code{allan} | @code{dispersion} @code{dispersion} | @code{freq} @code{freq} | @code{huffpuff} @code{huffpuff} | @code{panic} @code{panic} | @code{step} @code{srep} | @code{stepout} @code{stepout} .Oc
+@item @code{tinker}Oo@code{allan} @kbd{allan} |@code{dispersion} @kbd{dispersion} |@code{freq} @kbd{freq} |@code{huffpuff} @kbd{huffpuff} |@code{panic} @kbd{panic} |@code{step} @kbd{srep} |@code{stepout} @kbd{stepout}Oc
This command can be used to alter several system variables in
very exceptional circumstances.
It should occur in the
no help from the support group.
The variables operate as follows:
-@table @samp
-@item Cm
+@table @asis
+
+@item @code{allan} @kbd{allan}
The argument becomes the new value for the minimum Allan
intercept, which is a parameter of the PLL/FLL clock discipline
algorithm.
The value in log2 seconds defaults to 7 (1024 s), which is also the lower
limit.
-@item Cm
+@item @code{dispersion} @kbd{dispersion}
The argument becomes the new value for the dispersion increase rate,
normally .000015 s/s.
-@item Cm
+@item @code{freq} @kbd{freq}
The argument becomes the initial value of the frequency offset in
parts-per-million.
This overrides the value in the frequency file, if
present, and avoids the initial training state if it is not.
-@item Cm
+@item @code{huffpuff} @kbd{huffpuff}
The argument becomes the new value for the experimental
huff-n'-puff filter span, which determines the most recent interval
the algorithm will search for a minimum delay.
There
is no default, since the filter is not enabled unless this command
is given.
-@item Cm
+@item @code{panic} @kbd{panic}
The argument is the panic threshold, normally 1000 s.
If set to zero,
the panic sanity check is disabled and a clock offset of any value will
be accepted.
-@item Cm
+@item @code{step} @kbd{step}
The argument is the step threshold, which by default is 0.128 s.
It can
be set to any positive number in seconds.
Note: The kernel time discipline is
disabled if the step threshold is set to zero or greater than the
default.
-@item Cm
+@item @code{stepout} @kbd{stepout}
The argument is the stepout timeout, which by default is 900 s.
It can
be set to any positive number in seconds.
If set to zero, the stepout
pulses will not be suppressed.
@end table
-.It
-Xo
-Ic
-trap
-Ar
-host_address
-[@code{port} @code{port_number} ]
-[@code{interface} @code{interface_address} ]
+@item @code{trap} @kbd{host_address}[@code{port} @kbd{port_number}][@code{interface} @kbd{interface_address}]
This command configures a trap receiver at the given host
address and port number for sending messages with the specified
local interface address.
programs may also request their own trap dynamically, configuring a
trap receiver will ensure that no messages are lost when the server
is started.
-.It
-Cm
-hop
-Ar
-...
+@item @code{hop} @kbd{...}
This command specifies a list of TTL values in increasing order, up to 8
values can be specified.
In manycast mode these values are used in turn in
an expanding-ring search.
The default is eight multiples of 32 starting at
31.
-
-@end multitable
+@end table
This section was generated by @strong{AutoGen},
using the @code{agtexi-cmd} template and the option descriptions for the @code{ntp.conf} program.
This software is released under the NTP license, <http://ntp.org/license>.
@menu
+* ntp.conf Files:: Files
+* ntp.conf See Also:: See Also
+* ntp.conf Bugs:: Bugs
+* ntp.conf Notes:: Notes
+@end menu
+
+@node ntp.conf Files
+@subsection ntp.conf Files
+@table @asis
+
+@item @file{/etc/ntp.conf}
+the default name of the configuration file
+@item @file{ntp.keys}
+private MD5 keys
+@item @file{ntpkey}
+RSA private key
+@item @file{ntpkey_}@kbd{host}
+RSA public key
+@item @file{ntp_dh}
+Diffie-Hellman agreement parameters
+@end table
+@node ntp.conf See Also
+@subsection ntp.conf See Also
+@node SEE ALSO
+@section SEE ALSO
+
+
+@code{ntpd(1ntpdmdoc)},
+@code{ntpdc(1ntpdcmdoc)},
+@code{ntpq(1ntpqmdoc)}
+
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+@code{http://www.ntp.org/}.
+A snapshot of this documentation is available in HTML format in
+@file{/usr/share/doc/ntp}.
+@*
+ David L. Mills, @emph{Network Time Protocol (Version 4)}, RFC5905.
+@node ntp.conf Bugs
+@subsection ntp.conf Bugs
+The syntax checking is not picky; some combinations of
+ridiculous and even hilarious options and modes may not be
+detected.
+
+The
+@file{ntpkey_}@kbd{host}
+files are really digital
+certificates.
+These should be obtained via secure directory
+services when they become universally available.
+@node ntp.conf Notes
+@subsection ntp.conf Notes
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
#
# EDIT THIS FILE WITH CAUTION (invoke-ntp.keys.texi)
#
-# It has been AutoGen-ed January 2, 2013 at 02:19:22 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:09:27 PM by AutoGen 5.17.1pre11
# From the definitions ntp.keys.def
# and the template file agtexi-file.tpl
@end ignore
@code{ntpd(8)}
reads its keys from a file specified using the
-@code{-k} command line option or the
-@code{keys} statement in the configuration file.
+@code{-k}
+command line option or the
+@code{keys}
+statement in the configuration file.
While key number 0 is fixed by the NTP standard
(as 56 zero bits)
and may not be changed,
as the configuration file.
Key entries use a fixed format of the form
-.D1
-Ar
-keyno
-type
-key
+@example
+@kbd{keyno} @kbd{type} @kbd{key}
+@end example
where
-@code{keyno} is a positive integer (between 1 and 65534),
-@code{type} is the message digest algorithm,
+@kbd{keyno}
+is a positive integer (between 1 and 65534),
+@kbd{type}
+is the message digest algorithm,
and
-@code{key} is the key itself.
+@kbd{key}
+is the key itself.
The
-@code{key} may be given in a format
+@kbd{key}
+may be given in a format
controlled by the
-@code{type} field.
+@kbd{type}
+field.
The
-@code{type} .Li
-MD5
+@kbd{type}
+@code{MD5}
is always supported.
If
-.Li
-ntpd
+@code{ntpd}
was built with the OpenSSL library
then any digest library supported by that library may be specified.
However, if compliance with FIPS 140-2 is required the
-@code{type} must be either
-.Li
-SHA
+@kbd{type}
+must be either
+@code{SHA}
or
-.Li
-SHA1
-.
+@code{SHA1}.
What follows are some key types, and corresponding formats:
-@table @samp
-@item Li
+@table @asis
+
+@item @code{MD5}
The key is 1 to 16 printable characters terminated by
an EOL,
whitespace,
or
a
-.Li
#
(which is the "start of comment" character).
-@item Li
-@item Li
-@item Li
+@item @code{SHA}
+@item @code{SHA1}
+@item @code{RMD160}
The key is a hex-encoded ASCII string of 40 characters,
which is truncated as necessary.
@end table
This software is released under the NTP license, <http://ntp.org/license>.
@menu
+* ntp.keys Files:: Files
+* ntp.keys See Also:: See Also
+* ntp.keys Notes:: Notes
+@end menu
+
+@node ntp.keys Files
+@subsection ntp.keys Files
+@table @asis
+
+@item @file{/etc/ntp.keys}
+the default name of the configuration file
+@end table
+@node ntp.keys See Also
+@subsection ntp.keys See Also
+@code{ntp.conf(5)},
+@code{ntpd(1ntpdmdoc)},
+@code{ntpdate(1ntpdatemdoc)},
+@code{ntpdc(1ntpdcmdoc)},
+@code{sntp(1sntpmdoc)}
+@node ntp.keys Notes
+@subsection ntp.keys Notes
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
#
# EDIT THIS FILE WITH CAUTION (invoke-ntpd.texi)
#
-# It has been AutoGen-ed January 2, 2013 at 02:19:42 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:09:28 PM by AutoGen 5.17.1pre11
# From the definitions ntpd-opts.def
# and the template file agtexi-cmd.tpl
@end ignore
@code{ntp.conf(5)}
file cannot be read and no file is
specified by the
-@code{-c} option.
+@code{-c}
+option.
Various internal
@code{ntpd}
@exampleindent 0
@example
-ntpd - NTP daemon program - Ver. 4.2.7p343
+ntpd - NTP daemon program - Ver. 4.2.7p344
USAGE: ntpd [ -<flag> [<val>] | --<name>[@{=| @}<val>] ]... \
[ <server1> ... <serverN> ]
Flg Arg Option-Name Description
@node How NTP Operates
@section How NTP Operates
-How NTP Operates
+
The
@code{ntpd}
utility operates by exchanging messages with
set.
This initial delay to set the clock
can be safely and dramatically reduced using the
-@code{iburst} keyword with the
-@code{server} configuration
+@code{iburst}
+keyword with the
+@code{server}
+configuration
command, as described in
@code{ntp.conf(5)}.
to exit with a panic message to
the system log.
The
-@code{-g} option overrides this check and the
+@code{-g}
+option overrides this check and the
clock will be set to the server time regardless of the chip time
(up to 68 years in the past or future \(em
this is a limitation of the NTPv4 protocol).
In some applications, this behavior may be unacceptable.
There are several solutions, however.
If the
-@code{-x} option is included on the command line, the clock will
+@code{-x}
+option is included on the command line, the clock will
never be stepped and only slew corrections will be used.
But this choice comes with a cost that
should be carefully explored before deciding to use
the
-@code{-x} option.
+@code{-x}
+option.
The maximum slew rate possible is limited
to 500 parts-per-million (PPM) as a consequence of the correctness
principles on which the NTP protocol and algorithm design are
normal tracking mode.
In the most extreme cases
(the host
-@code{time.ien.it} comes to mind), there may be occasional
+@code{time.ien.it}
+comes to mind), there may be occasional
step/slew corrections and subsequent frequency corrections.
It
helps in these cases to use the
-@code{burst} keyword when
+@code{burst}
+keyword when
configuring the server, but
ONLY
when you have permission to do so from the owner of the target host.
@node Starting NTP (Best Current Practice)
@section Starting NTP (Best Current Practice)
-Starting NTP (Best Current Practice)
+
First, use the
-@code{iburst} option on your
-@code{server} entries.
+@code{iburst}
+option on your
+@code{server}
+entries.
If you can also keep a good
@file{ntp.drift}
As soon as possible in the startup sequence, start
@code{ntpd(8)}
with at least the
-@code{-g} and perhaps the
-@code{-N} options.
+@code{-g}
+and perhaps the
+@code{-N}
+options.
Then,
start the rest of your "normal" processes.
This will give
Finally,
if you have processes like
-@code{dovecot} or database servers
+@code{dovecot}
+or database servers
that require
monotonically-increasing time,
run
@code{ntp-wait(8)}
as late as possible in the boot sequence
(perhaps with the
-@code{-v} flag)
+@code{-v}
+flag)
and after
@code{ntp-wait(8)}
exits successfully
@node Frequency Discipline
@section Frequency Discipline
-Frequency Discipline
+
The
@code{ntpd}
behavior at startup depends on whether the
@node Operating Modes
@section Operating Modes
-Operating Modes
+
The
@code{ntpd}
utility can operate in any of several modes, including
processing, error checking and mitigation algorithms of
@code{ntpd}.
The
-@code{-q} option is intended for this purpose.
+@code{-q}
+option is intended for this purpose.
Setting this option will cause
@code{ntpd}
to exit just after
The procedure for initially
setting the clock is the same as in continuous mode; most
applications will probably want to specify the
-@code{iburst} keyword with the
-@code{server} configuration command.
+@code{iburst}
+keyword with the
+@code{server}
+configuration command.
With this
keyword a volley of messages are exchanged to groom the data and
the clock is set in about 10 s.
When kernel support is available to discipline the clock
frequency, which is the case for stock Solaris, Tru64, Linux and
-.Fx
-,
+Fx,
a useful feature is available to discipline the clock
frequency.
First,
@node Poll Interval Control
@section Poll Interval Control
-Poll Interval Control
+
This version of NTP includes an intricate state machine to
reduce the network load while maintaining a quality of
synchronization consistent with the observed jitter and wander.
default minimum of 64 s to the default maximum of 1,024 s.
The
default minimum can be changed with the
-@code{tinker} @code{minpoll} command to a value not less than 16 s.
+@code{tinker}
+@code{minpoll}
+command to a value not less than 16 s.
This value is used for all
configured associations, unless overridden by the
-@code{minpoll} option on the configuration command.
+@code{minpoll}
+option on the configuration command.
Note that most device drivers
will not operate properly if the poll interval is less than 64 s
and that the broadcast server and manycast client associations will
@node The huff-n'-puff Filter
@section The huff-n'-puff Filter
-The huff-n'-puff Filter
+
In scenarios where a considerable amount of data are to be
downloaded or uploaded over telephone modems, timekeeping quality
can be seriously degraded.
offset.
The filter is activated by the
-@code{tinker} command and
-@code{huffpuff} keyword, as described in
+@code{tinker}
+command and
+@code{huffpuff}
+keyword, as described in
@code{ntp.conf(5)}.
@node ntpd Files
@subsection ntpd Files
-@table @samp
-@item Pa
+@table @asis
+
+@item @file{/etc/ntp.conf}
the default name of the configuration file
-@item Pa
+@item @file{/etc/ntp.drift}
the default name of the drift file
-@item Pa
+@item @file{/etc/ntp.keys}
the default name of the key file
@end table
@node ntpd See Also
In addition to the manual pages provided,
comprehensive documentation is available on the world wide web
at
-.Li
-http://www.ntp.org/
-.
+@code{http://www.ntp.org/}.
A snapshot of this documentation is available in HTML format in
@file{/usr/share/doc/ntp}.
-.Rs
-.%A
-David
-L.
-Mills
-.%T
-Network
-Time
-Protocol
-(Version
-1)
-.%O
-RFC1059
-.Re
-.Rs
-.%A
-David
-L.
-Mills
-.%T
-Network
-Time
-Protocol
-(Version
-2)
-.%O
-RFC1119
-.Re
-.Rs
-.%A
-David
-L.
-Mills
-.%T
-Network
-Time
-Protocol
-(Version
-3)
-.%O
-RFC1305
-.Re
-.Rs
-.%A
-David
-L.
-Mills
-.%A
-J.
-Martin,
-Ed.
-.%A
-J.
-Burbank
-.%A
-W.
-Kasch
-.%T
-Network
-Time
-Protocol
-Version
-4:
-Protocol
-and
-Algorithms
-Specification
-.%O
-RFC5905
-.Re
-.Rs
-.%A
-David
-L.
-Mills
-.%A
-B.
-Haberman,
-Ed.
-.%T
-Network
-Time
-Protocol
-Version
-4:
-Autokey
-Specification
-.%O
-RFC5906
-.Re
-.Rs
-.%A
-H.
-Gerstung
-.%A
-C.
-Elliott
-.%A
-B.
-Haberman,
-Ed.
-.%T
-Definitions
-of
-Managed
-Objects
-for
-Network
-Time
-Protocol
-Version
-4:
-(NTPv4)
-.%O
-RFC5907
-.Re
-.Rs
-.%A
-R.
-Gayraud
-.%A
-B.
-Lourdelet
-.%T
-Network
-Time
-Protocol
-(NTP)
-Server
-Option
-for
-DHCPv6
-.%O
-RFC5908
-.Re
+@*
+ David L. Mills, @emph{Network Time Protocol (Version 1)}, RFC1059.
+@*
+ David L. Mills, @emph{Network Time Protocol (Version 2)}, RFC1119.
+@*
+ David L. Mills, @emph{Network Time Protocol (Version 3)}, RFC1305.
+@*
+ David L. Mills, J. Martin, Ed., J. Burbank, W. Kasch, @emph{Network Time Protocol Version 4: Protocol and Algorithms Specification}, RFC5905.
+@*
+ David L. Mills, B. Haberman, Ed., @emph{Network Time Protocol Version 4: Autokey Specification}, RFC5906.
+@*
+ H. Gerstung, C. Elliott, B. Haberman, Ed., @emph{Definitions of Managed Objects for Network Time Protocol Version 4: (NTPv4)}, RFC5907.
+@*
+ R. Gayraud, B. Lourdelet, @emph{Network Time Protocol (NTP) Server Option for DHCPv6}, RFC5908.
@node ntpd Bugs
@subsection ntpd Bugs
The
-.TH ntp.conf 5man "01 Jan 2013" "4.2.7p343" "File Formats"
+.TH ntp.conf 5man "03 Jan 2013" "4.2.7p344" "File Formats"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntp.man)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:33:41 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:10 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp.conf.def
.\" and the template file agman-cmd.tpl
.\"
All arguments must be options.
.PP
.SH DESCRIPTION
+The
+.B
+configuration file is read at initial startup by the
+.Xr ntpd 1ntpdmdoc
+daemon in order to specify the synchronization sources,
+modes and other related information.
+Usually, it is installed in the
+.Pa /etc
+directory,
+but could be installed elsewhere
+(see the daemon's
+c
+command line option).
+.PP
+The file format is similar to other
+.Ux
+configuration files.
+Comments begin with a
+.Ql #
+character and extend to the end of the line;
+blank lines are ignored.
+Configuration commands consist of an initial keyword
+followed by a list of arguments,
+some of which may be optional, separated by whitespace.
+Commands may not be continued over multiple lines.
+Arguments may be host names,
+host addresses written in numeric, dotted-quad form,
+integers, floating point numbers (when specifying times in seconds)
+and text strings.
+.PP
+The rest of this page describes the configuration and control options.
+The
+.Qq Notes on Configuring NTP and Setting up an NTP Subnet
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+contains an extended discussion of these options.
+In addition to the discussion of general
+.Sx Configuration Options ,
+there are sections describing the following supported functionality
+and the options used to control it:
+.in +4
+.ti -4
+\fB*\fP
+
+.Sx Authentication Support
+.ti -4
+\fB*\fP
+
+.Sx Monitoring Support
+.ti -4
+\fB*\fP
+
+.Sx Access Control Support
+.ti -4
+\fB*\fP
+
+.Sx Automatic NTP Configuration Options
+.ti -4
+\fB*\fP
+
+.Sx Reference Clock Support
+.ti -4
+\fB*\fP
+
+.Sx Miscellaneous Options
+.in -4
+.PP
+Following these is a section describing
+.Sx Miscellaneous Options .
+While there is a rich set of options available,
+the only required option is one or more
+.Ic pool ,
+.Ic server ,
+.Ic peer ,
+.Ic broadcast
+or
+.Ic manycastclient
+commands.
+.SH Configuration Support
+Following is a description of the configuration commands in
+NTPv4.
+These commands have the same basic functions as in NTPv3 and
+in some cases new functions and new arguments.
+There are two
+classes of commands, configuration commands that configure a
+persistent association with a remote server or peer or reference
+clock, and auxiliary commands that specify environmental variables
+that control various related operations.
+.SS Configuration Commands
+The various modes are determined by the command keyword and the
+type of the required IP address.
+Addresses are classed by type as
+(s) a remote server or peer (IPv4 class A, B and C), (b) the
+broadcast address of a local interface, (m) a multicast address (IPv4
+class D), or (r) a reference clock address (127.127.x.x).
+Note that
+only those options applicable to each command are listed below.
+Use
+of options not listed may not be caught as an error, but may result
+in some weird and even destructive behavior.
+.PP
+If the Basic Socket Interface Extensions for IPv6 (RFC-2553)
+is detected, support for the IPv6 address family is generated
+in addition to the default support of the IPv4 address family.
+In a few cases, including the reslist billboard generated
+by ntpdc, IPv6 addresses are automatically generated.
+IPv6 addresses can be identified by the presence of colons
+.Dq \&:
+in the address field.
+IPv6 addresses can be used almost everywhere where
+IPv4 addresses can be used,
+with the exception of reference clock addresses,
+which are always IPv4.
+.PP
+Note that in contexts where a host name is expected, a
+4
+qualifier preceding
+the host name forces DNS resolution to the IPv4 namespace,
+while a
+6
+qualifier forces DNS resolution to the IPv6 namespace.
+See IPv6 references for the
+equivalent classes for that address family.
+.TP
+.BR Xo Ic pool Ar address
+[ "\fIburst\fR" ]
+[ "\fIiburst\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fImaxpoll\fR" "\fImaxpoll\fR" ]
+.Xc
+.TP
+.BR Xo Ic server Ar address
+[ "\fIkey\fR" "\fIkey\fR" \&| "\fIautokey\fR" ]
+[ "\fIburst\fR" ]
+[ "\fIiburst\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fImaxpoll\fR" "\fImaxpoll\fR" ]
+.Xc
+.TP
+.BR Xo Ic peer Ar address
+[ "\fIkey\fR" "\fIkey\fR" \&| "\fIautokey\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fImaxpoll\fR" "\fImaxpoll\fR" ]
+.Xc
+.TP
+.BR Xo Ic broadcast Ar address
+[ "\fIkey\fR" "\fIkey\fR" \&| "\fIautokey\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fIttl\fR" "\fIttl\fR" ]
+.Xc
+.TP
+.BR Xo Ic manycastclient Ar address
+[ "\fIkey\fR" "\fIkey\fR" \&| "\fIautokey\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fImaxpoll\fR" "\fImaxpoll\fR" ]
+[ "\fIttl\fR" "\fIttl\fR" ]
+.Xc
+.PP
+These five commands specify the time server name or address to
+be used and the mode in which to operate.
+The
+\fIaddress\fR
+can be
+either a DNS name or an IP address in dotted-quad notation.
+Additional information on association behavior can be found in the
+.Qq Association Management
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.TP
+.BR Ic pool
+For type s addresses, this command mobilizes a persistent
+client mode association with a number of remote servers.
+In this mode the local clock can synchronized to the
+remote server, but the remote server can never be synchronized to
+the local clock.
+.TP
+.BR Ic server
+For type s and r addresses, this command mobilizes a persistent
+client mode association with the specified remote server or local
+radio clock.
+In this mode the local clock can synchronized to the
+remote server, but the remote server can never be synchronized to
+the local clock.
+This command should
+.I not
+be used for type
+b or m addresses.
+.TP
+.BR Ic peer
+For type s addresses (only), this command mobilizes a
+persistent symmetric-active mode association with the specified
+remote peer.
+In this mode the local clock can be synchronized to
+the remote peer or the remote peer can be synchronized to the local
+clock.
+This is useful in a network of servers where, depending on
+various failure scenarios, either the local or remote peer may be
+the better source of time.
+This command should NOT be used for type
+b, m or r addresses.
+.TP
+.BR Ic broadcast
+For type b and m addresses (only), this
+command mobilizes a persistent broadcast mode association.
+Multiple
+commands can be used to specify multiple local broadcast interfaces
+(subnets) and/or multiple multicast groups.
+Note that local
+broadcast messages go only to the interface associated with the
+subnet specified, but multicast messages go to all interfaces.
+In broadcast mode the local server sends periodic broadcast
+messages to a client population at the
+\fIaddress\fR
+specified, which is usually the broadcast address on (one of) the
+local network(s) or a multicast address assigned to NTP.
+The IANA
+has assigned the multicast group address IPv4 224.0.1.1 and
+IPv6 ff05::101 (site local) exclusively to
+NTP, but other nonconflicting addresses can be used to contain the
+messages within administrative boundaries.
+Ordinarily, this
+specification applies only to the local server operating as a
+sender; for operation as a broadcast client, see the
+.Ic broadcastclient
+or
+.Ic multicastclient
+commands
+below.
+.TP
+.BR Ic manycastclient
+For type m addresses (only), this command mobilizes a
+manycast client mode association for the multicast address
+specified.
+In this case a specific address must be supplied which
+matches the address used on the
+.Ic manycastserver
+command for
+the designated manycast servers.
+The NTP multicast address
+224.0.1.1 assigned by the IANA should NOT be used, unless specific
+means are taken to avoid spraying large areas of the Internet with
+these messages and causing a possibly massive implosion of replies
+at the sender.
+The
+.Ic manycastserver
+command specifies that the local server
+is to operate in client mode with the remote servers that are
+discovered as the result of broadcast/multicast messages.
+The
+client broadcasts a request message to the group address associated
+with the specified
+\fIaddress\fR
+and specifically enabled
+servers respond to these messages.
+The client selects the servers
+providing the best time and continues as with the
+.Ic server
+command.
+The remaining servers are discarded as if never
+heard.
+.PP
+Options:
+.TP
+.BR Cm autokey
+All packets sent to and received from the server or peer are to
+include authentication fields encrypted using the autokey scheme
+described in
+.Sx Authentication Options .
+.TP
+.BR Cm burst
+when the server is reachable, send a burst of eight packets
+instead of the usual one.
+The packet spacing is normally 2 s;
+however, the spacing between the first and second packets
+can be changed with the calldelay command to allow
+additional time for a modem or ISDN call to complete.
+This is designed to improve timekeeping quality
+with the
+.Ic server
+command and s addresses.
+.TP
+.BR Cm iburst
+When the server is unreachable, send a burst of eight packets
+instead of the usual one.
+The packet spacing is normally 2 s;
+however, the spacing between the first two packets can be
+changed with the calldelay command to allow
+additional time for a modem or ISDN call to complete.
+This is designed to speed the initial synchronization
+acquisition with the
+.Ic server
+command and s addresses and when
+.Xr ntpd 1ntpdmdoc
+is started with the
+q
+option.
+.TP
+.BR Cm key Ar key
+All packets sent to and received from the server or peer are to
+include authentication fields encrypted using the specified
+\fIkey\fR
+identifier with values from 1 to 65534, inclusive.
+The
+default is to include no encryption field.
+.TP
+.BR Cm minpoll Ar minpoll
+.TP
+.BR Cm maxpoll Ar maxpoll
+These options specify the minimum and maximum poll intervals
+for NTP messages, as a power of 2 in seconds
+The maximum poll
+interval defaults to 10 (1,024 s), but can be increased by the
+.Cm maxpoll
+option to an upper limit of 17 (36.4 h).
+The
+minimum poll interval defaults to 6 (64 s), but can be decreased by
+the
+.Cm minpoll
+option to a lower limit of 4 (16 s).
+.TP
+.BR Cm noselect
+Marks the server as unused, except for display purposes.
+The server is discarded by the selection algroithm.
+.TP
+.BR Cm prefer
+Marks the server as preferred.
+All other things being equal,
+this host will be chosen for synchronization among a set of
+correctly operating hosts.
+See the
+.Qq Mitigation Rules and the prefer Keyword
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+for further information.
+.TP
+.BR Cm ttl Ar ttl
+This option is used only with broadcast server and manycast
+client modes.
+It specifies the time-to-live
+\fIttl\fR
+to
+use on broadcast server and multicast server and the maximum
+\fIttl\fR
+for the expanding ring search with manycast
+client packets.
+Selection of the proper value, which defaults to
+127, is something of a black art and should be coordinated with the
+network administrator.
+.TP
+.BR Cm version Ar version
+Specifies the version number to be used for outgoing NTP
+packets.
+Versions 1-4 are the choices, with version 4 the
+default.
+.SS Auxiliary Commands
+.TP
+.BR Ic broadcastclient
+This command enables reception of broadcast server messages to
+any local interface (type b) address.
+Upon receiving a message for
+the first time, the broadcast client measures the nominal server
+propagation delay using a brief client/server exchange with the
+server, then enters the broadcast client mode, in which it
+synchronizes to succeeding broadcast messages.
+Note that, in order
+to avoid accidental or malicious disruption in this mode, both the
+server and client should operate using symmetric-key or public-key
+authentication as described in
+.Sx Authentication Options .
+.TP
+.BR Ic manycastserver Ar address ...
+This command enables reception of manycast client messages to
+the multicast group address(es) (type m) specified.
+At least one
+address is required, but the NTP multicast address 224.0.1.1
+assigned by the IANA should NOT be used, unless specific means are
+taken to limit the span of the reply and avoid a possibly massive
+implosion at the original sender.
+Note that, in order to avoid
+accidental or malicious disruption in this mode, both the server
+and client should operate using symmetric-key or public-key
+authentication as described in
+.Sx Authentication Options .
+.TP
+.BR Ic multicastclient Ar address ...
+This command enables reception of multicast server messages to
+the multicast group address(es) (type m) specified.
+Upon receiving
+a message for the first time, the multicast client measures the
+nominal server propagation delay using a brief client/server
+exchange with the server, then enters the broadcast client mode, in
+which it synchronizes to succeeding multicast messages.
+Note that,
+in order to avoid accidental or malicious disruption in this mode,
+both the server and client should operate using symmetric-key or
+public-key authentication as described in
+.Sx Authentication Options .
+.SH Authentication Support
+Authentication support allows the NTP client to verify that the
+server is in fact known and trusted and not an intruder intending
+accidentally or on purpose to masquerade as that server.
+The NTPv3
+specification RFC-1305 defines a scheme which provides
+cryptographic authentication of received NTP packets.
+Originally,
+this was done using the Data Encryption Standard (DES) algorithm
+operating in Cipher Block Chaining (CBC) mode, commonly called
+DES-CBC.
+Subsequently, this was replaced by the RSA Message Digest
+5 (MD5) algorithm using a private key, commonly called keyed-MD5.
+Either algorithm computes a message digest, or one-way hash, which
+can be used to verify the server has the correct private key and
+key identifier.
+.PP
+NTPv4 retains the NTPv3 scheme, properly described as symmetric key
+cryptography and, in addition, provides a new Autokey scheme
+based on public key cryptography.
+Public key cryptography is generally considered more secure
+than symmetric key cryptography, since the security is based
+on a private value which is generated by each server and
+never revealed.
+With Autokey all key distribution and
+management functions involve only public values, which
+considerably simplifies key distribution and storage.
+Public key management is based on X.509 certificates,
+which can be provided by commercial services or
+produced by utility programs in the OpenSSL software library
+or the NTPv4 distribution.
+.PP
+While the algorithms for symmetric key cryptography are
+included in the NTPv4 distribution, public key cryptography
+requires the OpenSSL software library to be installed
+before building the NTP distribution.
+Directions for doing that
+are on the Building and Installing the Distribution page.
+.PP
+Authentication is configured separately for each association
+using the
+.Cm key
+or
+.Cm autokey
+subcommand on the
+.Ic peer ,
+.Ic server ,
+.Ic broadcast
+and
+.Ic manycastclient
+configuration commands as described in
+.Sx Configuration Options
+page.
+The authentication
+options described below specify the locations of the key files,
+if other than default, which symmetric keys are trusted
+and the interval between various operations, if other than default.
+.PP
+Authentication is always enabled,
+although ineffective if not configured as
+described below.
+If a NTP packet arrives
+including a message authentication
+code (MAC), it is accepted only if it
+passes all cryptographic checks.
+The
+checks require correct key ID, key value
+and message digest.
+If the packet has
+been modified in any way or replayed
+by an intruder, it will fail one or more
+of these checks and be discarded.
+Furthermore, the Autokey scheme requires a
+preliminary protocol exchange to obtain
+the server certificate, verify its
+credentials and initialize the protocol
+.PP
+The
+.Cm auth
+flag controls whether new associations or
+remote configuration commands require cryptographic authentication.
+This flag can be set or reset by the
+.Ic enable
+and
+.Ic disable
+commands and also by remote
+configuration commands sent by a
+.Xr ntpdc 1ntpdcmdoc
+program running in
+another machine.
+If this flag is enabled, which is the default
+case, new broadcast client and symmetric passive associations and
+remote configuration commands must be cryptographically
+authenticated using either symmetric key or public key cryptography.
+If this
+flag is disabled, these operations are effective
+even if not cryptographic
+authenticated.
+It should be understood
+that operating with the
+.Ic auth
+flag disabled invites a significant vulnerability
+where a rogue hacker can
+masquerade as a falseticker and seriously
+disrupt system timekeeping.
+It is
+important to note that this flag has no purpose
+other than to allow or disallow
+a new association in response to new broadcast
+and symmetric active messages
+and remote configuration commands and, in particular,
+the flag has no effect on
+the authentication process itself.
+.PP
+An attractive alternative where multicast support is available
+is manycast mode, in which clients periodically troll
+for servers as described in the
+.Sx Automatic NTP Configuration Options
+page.
+Either symmetric key or public key
+cryptographic authentication can be used in this mode.
+The principle advantage
+of manycast mode is that potential servers need not be
+configured in advance,
+since the client finds them during regular operation,
+and the configuration
+files for all clients can be identical.
+.PP
+The security model and protocol schemes for
+both symmetric key and public key
+cryptography are summarized below;
+further details are in the briefings, papers
+and reports at the NTP project page linked from
+.Li http://www.ntp.org/ .
+.SS Symmetric-Key Cryptography
+The original RFC-1305 specification allows any one of possibly
+65,534 keys, each distinguished by a 32-bit key identifier, to
+authenticate an association.
+The servers and clients involved must
+agree on the key and key identifier to
+authenticate NTP packets.
+Keys and
+related information are specified in a key
+file, usually called
+.Pa ntp.keys ,
+which must be distributed and stored using
+secure means beyond the scope of the NTP protocol itself.
+Besides the keys used
+for ordinary NTP associations,
+additional keys can be used as passwords for the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+utility programs.
+.PP
+When
+.Xr ntpd 1ntpdmdoc
+is first started, it reads the key file specified in the
+.Ic keys
+configuration command and installs the keys
+in the key cache.
+However,
+individual keys must be activated with the
+.Ic trusted
+command before use.
+This
+allows, for instance, the installation of possibly
+several batches of keys and
+then activating or deactivating each batch
+remotely using
+.Xr ntpdc 1ntpdcmdoc .
+This also provides a revocation capability that can be used
+if a key becomes compromised.
+The
+.Ic requestkey
+command selects the key used as the password for the
+.Xr ntpdc 1ntpdcmdoc
+utility, while the
+.Ic controlkey
+command selects the key used as the password for the
+.Xr ntpq 1ntpqmdoc
+utility.
+.SS Public Key Cryptography
+NTPv4 supports the original NTPv3 symmetric key scheme
+described in RFC-1305 and in addition the Autokey protocol,
+which is based on public key cryptography.
+The Autokey Version 2 protocol described on the Autokey Protocol
+page verifies packet integrity using MD5 message digests
+and verifies the source with digital signatures and any of several
+digest/signature schemes.
+Optional identity schemes described on the Identity Schemes
+page and based on cryptographic challenge/response algorithms
+are also available.
+Using all of these schemes provides strong security against
+replay with or without modification, spoofing, masquerade
+and most forms of clogging attacks.
+.\" .Pp
+.\" The cryptographic means necessary for all Autokey operations
+.\" is provided by the OpenSSL software library.
+.\" This library is available from http://www.openssl.org/
+.\" and can be installed using the procedures outlined
+.\" in the Building and Installing the Distribution page.
+.\" Once installed,
+.\" the configure and build
+.\" process automatically detects the library and links
+.\" the library routines required.
+.PP
+The Autokey protocol has several modes of operation
+corresponding to the various NTP modes supported.
+Most modes use a special cookie which can be
+computed independently by the client and server,
+but encrypted in transmission.
+All modes use in addition a variant of the S-KEY scheme,
+in which a pseudo-random key list is generated and used
+in reverse order.
+These schemes are described along with an executive summary,
+current status, briefing slides and reading list on the
+.Sx Autonomous Authentication
+page.
+.PP
+The specific cryptographic environment used by Autokey servers
+and clients is determined by a set of files
+and soft links generated by the
+.Xr ntp-keygen 1ntpkeygenmdoc
+program.
+This includes a required host key file,
+required certificate file and optional sign key file,
+leapsecond file and identity scheme files.
+The
+digest/signature scheme is specified in the X.509 certificate
+along with the matching sign key.
+There are several schemes
+available in the OpenSSL software library, each identified
+by a specific string such as
+.Cm md5WithRSAEncryption ,
+which stands for the MD5 message digest with RSA
+encryption scheme.
+The current NTP distribution supports
+all the schemes in the OpenSSL library, including
+those based on RSA and DSA digital signatures.
+.PP
+NTP secure groups can be used to define cryptographic compartments
+and security hierarchies.
+It is important that every host
+in the group be able to construct a certificate trail to one
+or more trusted hosts in the same group.
+Each group
+host runs the Autokey protocol to obtain the certificates
+for all hosts along the trail to one or more trusted hosts.
+This requires the configuration file in all hosts to be
+engineered so that, even under anticipated failure conditions,
+the NTP subnet will form such that every group host can find
+a trail to at least one trusted host.
+.SS Naming and Addressing
+It is important to note that Autokey does not use DNS to
+resolve addresses, since DNS can't be completely trusted
+until the name servers have synchronized clocks.
+The cryptographic name used by Autokey to bind the host identity
+credentials and cryptographic values must be independent
+of interface, network and any other naming convention.
+The name appears in the host certificate in either or both
+the subject and issuer fields, so protection against
+DNS compromise is essential.
+.PP
+By convention, the name of an Autokey host is the name returned
+by the Unix
+.Xr gethostname 2
+system call or equivalent in other systems.
+By the system design
+model, there are no provisions to allow alternate names or aliases.
+However, this is not to say that DNS aliases, different names
+for each interface, etc., are constrained in any way.
+.PP
+It is also important to note that Autokey verifies authenticity
+using the host name, network address and public keys,
+all of which are bound together by the protocol specifically
+to deflect masquerade attacks.
+For this reason Autokey
+includes the source and destinatino IP addresses in message digest
+computations and so the same addresses must be available
+at both the server and client.
+For this reason operation
+with network address translation schemes is not possible.
+This reflects the intended robust security model where government
+and corporate NTP servers are operated outside firewall perimeters.
+.SS Operation
+A specific combination of authentication scheme (none,
+symmetric key, public key) and identity scheme is called
+a cryptotype, although not all combinations are compatible.
+There may be management configurations where the clients,
+servers and peers may not all support the same cryptotypes.
+A secure NTPv4 subnet can be configured in many ways while
+keeping in mind the principles explained above and
+in this section.
+Note however that some cryptotype
+combinations may successfully interoperate with each other,
+but may not represent good security practice.
+.PP
+The cryptotype of an association is determined at the time
+of mobilization, either at configuration time or some time
+later when a message of appropriate cryptotype arrives.
+When mobilized by a
+.Ic server
+or
+.Ic peer
+configuration command and no
+.Ic key
+or
+.Ic autokey
+subcommands are present, the association is not
+authenticated; if the
+.Ic key
+subcommand is present, the association is authenticated
+using the symmetric key ID specified; if the
+.Ic autokey
+subcommand is present, the association is authenticated
+using Autokey.
+.PP
+When multiple identity schemes are supported in the Autokey
+protocol, the first message exchange determines which one is used.
+The client request message contains bits corresponding
+to which schemes it has available.
+The server response message
+contains bits corresponding to which schemes it has available.
+Both server and client match the received bits with their own
+and select a common scheme.
+.PP
+Following the principle that time is a public value,
+a server responds to any client packet that matches
+its cryptotype capabilities.
+Thus, a server receiving
+an unauthenticated packet will respond with an unauthenticated
+packet, while the same server receiving a packet of a cryptotype
+it supports will respond with packets of that cryptotype.
+However, unconfigured broadcast or manycast client
+associations or symmetric passive associations will not be
+mobilized unless the server supports a cryptotype compatible
+with the first packet received.
+By default, unauthenticated associations will not be mobilized
+unless overridden in a decidedly dangerous way.
+.PP
+Some examples may help to reduce confusion.
+Client Alice has no specific cryptotype selected.
+Server Bob has both a symmetric key file and minimal Autokey files.
+Alice's unauthenticated messages arrive at Bob, who replies with
+unauthenticated messages.
+Cathy has a copy of Bob's symmetric
+key file and has selected key ID 4 in messages to Bob.
+Bob verifies the message with his key ID 4.
+If it's the
+same key and the message is verified, Bob sends Cathy a reply
+authenticated with that key.
+If verification fails,
+Bob sends Cathy a thing called a crypto-NAK, which tells her
+something broke.
+She can see the evidence using the
+.Xr ntpq 1ntpqmdoc
+program.
+.PP
+Denise has rolled her own host key and certificate.
+She also uses one of the identity schemes as Bob.
+She sends the first Autokey message to Bob and they
+both dance the protocol authentication and identity steps.
+If all comes out okay, Denise and Bob continue as described above.
+.PP
+It should be clear from the above that Bob can support
+all the girls at the same time, as long as he has compatible
+authentication and identity credentials.
+Now, Bob can act just like the girls in his own choice of servers;
+he can run multiple configured associations with multiple different
+servers (or the same server, although that might not be useful).
+But, wise security policy might preclude some cryptotype
+combinations; for instance, running an identity scheme
+with one server and no authentication with another might not be wise.
+.SS Key Management
+The cryptographic values used by the Autokey protocol are
+incorporated as a set of files generated by the
+.Xr ntp-keygen 1ntpkeygenmdoc
+utility program, including symmetric key, host key and
+public certificate files, as well as sign key, identity parameters
+and leapseconds files.
+Alternatively, host and sign keys and
+certificate files can be generated by the OpenSSL utilities
+and certificates can be imported from public certificate
+authorities.
+Note that symmetric keys are necessary for the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+utility programs.
+The remaining files are necessary only for the
+Autokey protocol.
+.PP
+Certificates imported from OpenSSL or public certificate
+authorities have certian limitations.
+The certificate should be in ASN.1 syntax, X.509 Version 3
+format and encoded in PEM, which is the same format
+used by OpenSSL.
+The overall length of the certificate encoded
+in ASN.1 must not exceed 1024 bytes.
+The subject distinguished
+name field (CN) is the fully qualified name of the host
+on which it is used; the remaining subject fields are ignored.
+The certificate extension fields must not contain either
+a subject key identifier or a issuer key identifier field;
+however, an extended key usage field for a trusted host must
+contain the value
+.Cm trustRoot ; .
+Other extension fields are ignored.
+.SS Authentication Commands
+.TP
+.BR Ic autokey Op Ar logsec
+Specifies the interval between regenerations of the session key
+list used with the Autokey protocol.
+Note that the size of the key
+list for each association depends on this interval and the current
+poll interval.
+The default value is 12 (4096 s or about 1.1 hours).
+For poll intervals above the specified interval, a session key list
+with a single entry will be regenerated for every message
+sent.
+.TP
+.BR Ic controlkey Ar key
+Specifies the key identifier to use with the
+.Xr ntpq 1ntpqmdoc
+utility, which uses the standard
+protocol defined in RFC-1305.
+The
+\fIkey\fR
+argument is
+the key identifier for a trusted key, where the value can be in the
+range 1 to 65,534, inclusive.
+.TP
+.BR Xo Ic crypto
+[ "\fIcert\fR" "\fIfile\fR" ]
+[ "\fIleap\fR" "\fIfile\fR" ]
+[ "\fIrandfile\fR" "\fIfile\fR" ]
+[ "\fIhost\fR" "\fIfile\fR" ]
+[ "\fIsign\fR" "\fIfile\fR" ]
+[ "\fIgq\fR" "\fIfile\fR" ]
+[ "\fIgqpar\fR" "\fIfile\fR" ]
+[ "\fIiffpar\fR" "\fIfile\fR" ]
+[ "\fImvpar\fR" "\fIfile\fR" ]
+[ "\fIpw\fR" "\fIpassword\fR" ]
+.Xc
+This command requires the OpenSSL library.
+It activates public key
+cryptography, selects the message digest and signature
+encryption scheme and loads the required private and public
+values described above.
+If one or more files are left unspecified,
+the default names are used as described above.
+Unless the complete path and name of the file are specified, the
+location of a file is relative to the keys directory specified
+in the
+.Ic keysdir
+command or default
+.Pa /usr/local/etc .
+Following are the subcommands:
+.in +4
+.ti -4
+.IR Cm cert Ar file
+Specifies the location of the required host public certificate file.
+This overrides the link
+.Pa ntpkey_cert_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm gqpar Ar file
+Specifies the location of the optional GQ parameters file.
+This
+overrides the link
+.Pa ntpkey_gq_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm host Ar file
+Specifies the location of the required host key file.
+This overrides
+the link
+.Pa ntpkey_key_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm iffpar Ar file
+Specifies the location of the optional IFF parameters file.This
+overrides the link
+.Pa ntpkey_iff_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm leap Ar file
+Specifies the location of the optional leapsecond file.
+This overrides the link
+.Pa ntpkey_leap
+in the keys directory.
+.ti -4
+.IR Cm mvpar Ar file
+Specifies the location of the optional MV parameters file.
+This
+overrides the link
+.Pa ntpkey_mv_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm pw Ar password
+Specifies the password to decrypt files containing private keys and
+identity parameters.
+This is required only if these files have been
+encrypted.
+.ti -4
+.IR Cm randfile Ar file
+Specifies the location of the random seed file used by the OpenSSL
+library.
+The defaults are described in the main text above.
+.ti -4
+.IR Cm sign Ar file
+Specifies the location of the optional sign key file.
+This overrides
+the link
+.Pa ntpkey_sign_ Ns Ar hostname
+in the keys directory.
+If this file is
+not found, the host key is also the sign key.
+.in -4
+.TP
+.BR Ic keys Ar keyfile
+Specifies the complete path and location of the MD5 key file
+containing the keys and key identifiers used by
+.Xr ntpd 1ntpdmdoc ,
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+when operating with symmetric key cryptography.
+This is the same operation as the
+k
+command line option.
+.TP
+.BR Ic keysdir Ar path
+This command specifies the default directory path for
+cryptographic keys, parameters and certificates.
+The default is
+.Pa /usr/local/etc/ .
+.TP
+.BR Ic requestkey Ar key
+Specifies the key identifier to use with the
+.Xr ntpdc 1ntpdcmdoc
+utility program, which uses a
+proprietary protocol specific to this implementation of
+.Xr ntpd 1ntpdmdoc .
+The
+\fIkey\fR
+argument is a key identifier
+for the trusted key, where the value can be in the range 1 to
+65,534, inclusive.
+.TP
+.BR Ic revoke Ar logsec
+Specifies the interval between re-randomization of certain
+cryptographic values used by the Autokey scheme, as a power of 2 in
+seconds.
+These values need to be updated frequently in order to
+deflect brute-force attacks on the algorithms of the scheme;
+however, updating some values is a relatively expensive operation.
+The default interval is 16 (65,536 s or about 18 hours).
+For poll
+intervals above the specified interval, the values will be updated
+for every message sent.
+.TP
+.BR Ic trustedkey Ar key ...
+Specifies the key identifiers which are trusted for the
+purposes of authenticating peers with symmetric key cryptography,
+as well as keys used by the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+programs.
+The authentication procedures require that both the local
+and remote servers share the same key and key identifier for this
+purpose, although different keys can be used with different
+servers.
+The
+\fIkey\fR
+arguments are 32-bit unsigned
+integers with values from 1 to 65,534.
+.SS Error Codes
+The following error codes are reported via the NTP control
+and monitoring protocol trap mechanism.
+.TP
+.BR 101
+.Pq bad field format or length
+The packet has invalid version, length or format.
+.TP
+.BR 102
+.Pq bad timestamp
+The packet timestamp is the same or older than the most recent received.
+This could be due to a replay or a server clock time step.
+.TP
+.BR 103
+.Pq bad filestamp
+The packet filestamp is the same or older than the most recent received.
+This could be due to a replay or a key file generation error.
+.TP
+.BR 104
+.Pq bad or missing public key
+The public key is missing, has incorrect format or is an unsupported type.
+.TP
+.BR 105
+.Pq unsupported digest type
+The server requires an unsupported digest/signature scheme.
+.TP
+.BR 106
+.Pq mismatched digest types
+Not used.
+.TP
+.BR 107
+.Pq bad signature length
+The signature length does not match the current public key.
+.TP
+.BR 108
+.Pq signature not verified
+The message fails the signature check.
+It could be bogus or signed by a
+different private key.
+.TP
+.BR 109
+.Pq certificate not verified
+The certificate is invalid or signed with the wrong key.
+.TP
+.BR 110
+.Pq certificate not verified
+The certificate is not yet valid or has expired or the signature could not
+be verified.
+.TP
+.BR 111
+.Pq bad or missing cookie
+The cookie is missing, corrupted or bogus.
+.TP
+.BR 112
+.Pq bad or missing leapseconds table
+The leapseconds table is missing, corrupted or bogus.
+.TP
+.BR 113
+.Pq bad or missing certificate
+The certificate is missing, corrupted or bogus.
+.TP
+.BR 114
+.Pq bad or missing identity
+The identity key is missing, corrupt or bogus.
+.SH Monitoring Support
+.Xr ntpd 1ntpdmdoc
+includes a comprehensive monitoring facility suitable
+for continuous, long term recording of server and client
+timekeeping performance.
+See the
+.Ic statistics
+command below
+for a listing and example of each type of statistics currently
+supported.
+Statistic files are managed using file generation sets
+and scripts in the
+.Pa ./scripts
+directory of this distribution.
+Using
+these facilities and
+.Ux
+.Xr cron 8
+jobs, the data can be
+automatically summarized and archived for retrospective analysis.
+.SS Monitoring Commands
+.TP
+.BR Ic statistics Ar name ...
+Enables writing of statistics records.
+Currently, four kinds of
+\fIname\fR
+statistics are supported.
+.in +4
+.ti -4
+.IR Cm clockstats
+Enables recording of clock driver statistics information.
+Each update
+received from a clock driver appends a line of the following form to
+the file generation set named
+.Cm clockstats :
+.br
+.in +4
+.nf
+49213 525.624 127.127.4.1 93 226 00:08:29.606 D
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The next field shows the
+clock address in dotted-quad notation.
+The final field shows the last
+timecode received from the clock in decoded ASCII format, where
+meaningful.
+In some clock drivers a good deal of additional information
+can be gathered and displayed as well.
+See information specific to each
+clock for further details.
+.ti -4
+.IR Cm cryptostats
+This option requires the OpenSSL cryptographic software library.
+It
+enables recording of cryptographic public key protocol information.
+Each message received by the protocol module appends a line of the
+following form to the file generation set named
+.Cm cryptostats :
+.br
+.in +4
+.nf
+49213 525.624 127.127.4.1 message
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The next field shows the peer
+address in dotted-quad notation, The final message field includes the
+message type and certain ancillary information.
+See the
+.Sx Authentication Options
+section for further information.
+.ti -4
+.IR Cm loopstats
+Enables recording of loop filter statistics information.
+Each
+update of the local clock outputs a line of the following form to
+the file generation set named
+.Cm loopstats :
+.br
+.in +4
+.nf
+50935 75440.031 0.000006019 13.778190 0.000351733 0.0133806
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next five fields
+show time offset (seconds), frequency offset (parts per million -
+PPM), RMS jitter (seconds), Allan deviation (PPM) and clock
+discipline time constant.
+.ti -4
+.IR Cm peerstats
+Enables recording of peer statistics information.
+This includes
+statistics records of all peers of a NTP server and of special
+signals, where present and configured.
+Each valid update appends a
+line of the following form to the current element of a file
+generation set named
+.Cm peerstats :
+.br
+.in +4
+.nf
+48773 10847.650 127.127.4.1 9714 -0.001605376 0.000000000 0.001424877 0.000958674
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next two fields
+show the peer address in dotted-quad notation and status,
+respectively.
+The status field is encoded in hex in the format
+described in Appendix A of the NTP specification RFC 1305.
+The final four fields show the offset,
+delay, dispersion and RMS jitter, all in seconds.
+.ti -4
+.IR Cm rawstats
+Enables recording of raw-timestamp statistics information.
+This
+includes statistics records of all peers of a NTP server and of
+special signals, where present and configured.
+Each NTP message
+received from a peer or clock driver appends a line of the
+following form to the file generation set named
+.Cm rawstats :
+.br
+.in +4
+.nf
+50928 2132.543 128.4.1.1 128.4.1.20 3102453281.584327000 3102453281.58622800031 02453332.540806000 3102453332.541458000
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next two fields
+show the remote peer or clock address followed by the local address
+in dotted-quad notation.
+The final four fields show the originate,
+receive, transmit and final NTP timestamps in order.
+The timestamp
+values are as received and before processing by the various data
+smoothing and mitigation algorithms.
+.ti -4
+.IR Cm sysstats
+Enables recording of ntpd statistics counters on a periodic basis.
+Each
+hour a line of the following form is appended to the file generation
+set named
+.Cm sysstats :
+.br
+.in +4
+.nf
+50928 2132.543 36000 81965 0 9546 56 71793 512 540 10 147
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The remaining ten fields show
+the statistics counter values accumulated since the last generated
+line.
+.in +4
+.ti -4
+.IR Time since restart Cm 36000
+Time in hours since the system was last rebooted.
+.ti -4
+.IR Packets received Cm 81965
+Total number of packets received.
+.ti -4
+.IR Packets processed Cm 0
+Number of packets received in response to previous packets sent
+.ti -4
+.IR Current version Cm 9546
+Number of packets matching the current NTP version.
+.ti -4
+.IR Previous version Cm 56
+Number of packets matching the previous NTP version.
+.ti -4
+.IR Bad version Cm 71793
+Number of packets matching neither NTP version.
+.ti -4
+.IR Access denied Cm 512
+Number of packets denied access for any reason.
+.ti -4
+.IR Bad length or format Cm 540
+Number of packets with invalid length, format or port number.
+.ti -4
+.IR Bad authentication Cm 10
+Number of packets not verified as authentic.
+.ti -4
+.IR Rate exceeded Cm 147
+Number of packets discarded due to rate limitation.
+.in -4
+.ti -4
+.IR Cm statsdir Ar directory_path
+Indicates the full path of a directory where statistics files
+should be created (see below).
+This keyword allows
+the (otherwise constant)
+.Cm filegen
+filename prefix to be modified for file generation sets, which
+is useful for handling statistics logs.
+.ti -4
+.IR Cm filegen Ar name Xo
+[ "\fIfile\fR" "\fIfilename\fR" ]
+[ "\fItype\fR" "\fItypename\fR" ]
+[ "\fIlink\fR" | nolink ]
+[ "\fIenable\fR" | disable ]
+.Xc
+Configures setting of generation file set name.
+Generation
+file sets provide a means for handling files that are
+continuously growing during the lifetime of a server.
+Server statistics are a typical example for such files.
+Generation file sets provide access to a set of files used
+to store the actual data.
+At any time at most one element
+of the set is being written to.
+The type given specifies
+when and how data will be directed to a new element of the set.
+This way, information stored in elements of a file set
+that are currently unused are available for administrational
+operations without the risk of disturbing the operation of ntpd.
+(Most important: they can be removed to free space for new data
+produced.)
+.PP
+Note that this command can be sent from the
+.Xr ntpdc 1ntpdcmdoc
+program running at a remote location.
+.in +4
+.ti -4
+.IR Cm name
+This is the type of the statistics records, as shown in the
+.Cm statistics
+command.
+.ti -4
+.IR Cm file Ar filename
+This is the file name for the statistics records.
+Filenames of set
+members are built from three concatenated elements
+\fICm prefix ,\fR
+\fICm filename\fR
+and
+\fICm suffix :\fR
+.in +4
+.ti -4
+.IR Cm prefix
+This is a constant filename path.
+It is not subject to
+modifications via the
+\fIfilegen\fR
+option.
+It is defined by the
+server, usually specified as a compile-time constant.
+It may,
+however, be configurable for individual file generation sets
+via other commands.
+For example, the prefix used with
+\fIloopstats\fR
+and
+\fIpeerstats\fR
+generation can be configured using the
+\fIstatsdir\fR
+option explained above.
+.ti -4
+.IR Cm filename
+This string is directly concatenated to the prefix mentioned
+above (no intervening
+.Ql / ) .
+This can be modified using
+the file argument to the
+\fIfilegen\fR
+statement.
+No
+.Pa ..
+elements are
+allowed in this component to prevent filenames referring to
+parts outside the filesystem hierarchy denoted by
+\fIprefix .\fR
+.ti -4
+.IR Cm suffix
+This part is reflects individual elements of a file set.
+It is
+generated according to the type of a file set.
+.in -4
+.ti -4
+.IR Cm type Ar typename
+A file generation set is characterized by its type.
+The following
+types are supported:
+.in +4
+.ti -4
+.IR Cm none
+The file set is actually a single plain file.
+.ti -4
+.IR Cm pid
+One element of file set is used per incarnation of a ntpd
+server.
+This type does not perform any changes to file set
+members during runtime, however it provides an easy way of
+separating files belonging to different
+.Xr ntpd 1ntpdmdoc
+server incarnations.
+The set member filename is built by appending a
+.Ql \&.
+to concatenated
+\fIprefix\fR
+and
+\fIfilename\fR
+strings, and
+appending the decimal representation of the process ID of the
+.Xr ntpd 1ntpdmdoc
+server process.
+.ti -4
+.IR Cm day
+One file generation set element is created per day.
+A day is
+defined as the period between 00:00 and 24:00 UTC.
+The file set
+member suffix consists of a
+.Ql \&.
+and a day specification in
+the form
+.Cm YYYYMMdd .
+.Cm YYYY
+is a 4-digit year number (e.g., 1992).
+.Cm MM
+is a two digit month number.
+.Cm dd
+is a two digit day number.
+Thus, all information written at 10 December 1992 would end up
+in a file named
+\fIprefix\fR
+\fIfilename Ns .19921210 .\fR
+.ti -4
+.IR Cm week
+Any file set member contains data related to a certain week of
+a year.
+The term week is defined by computing day-of-year
+modulo 7.
+Elements of such a file generation set are
+distinguished by appending the following suffix to the file set
+filename base: A dot, a 4-digit year number, the letter
+.Cm W ,
+and a 2-digit week number.
+For example, information from January,
+10th 1992 would end up in a file with suffix
+.No . Ns Ar 1992W1 .
+.ti -4
+.IR Cm month
+One generation file set element is generated per month.
+The
+file name suffix consists of a dot, a 4-digit year number, and
+a 2-digit month.
+.ti -4
+.IR Cm year
+One generation file element is generated per year.
+The filename
+suffix consists of a dot and a 4 digit year number.
+.ti -4
+.IR Cm age
+This type of file generation sets changes to a new element of
+the file set every 24 hours of server operation.
+The filename
+suffix consists of a dot, the letter
+.Cm a ,
+and an 8-digit number.
+This number is taken to be the number of seconds the server is
+running at the start of the corresponding 24-hour period.
+Information is only written to a file generation by specifying
+.Cm enable ;
+output is prevented by specifying
+.Cm disable .
+.in -4
+.ti -4
+.IR Cm link | nolink
+It is convenient to be able to access the current element of a file
+generation set by a fixed name.
+This feature is enabled by
+specifying
+.Cm link
+and disabled using
+.Cm nolink .
+If link is specified, a
+hard link from the current file set element to a file without
+suffix is created.
+When there is already a file with this name and
+the number of links of this file is one, it is renamed appending a
+dot, the letter
+.Cm C ,
+and the pid of the ntpd server process.
+When the
+number of links is greater than one, the file is unlinked.
+This
+allows the current file to be accessed by a constant name.
+.ti -4
+.IR Cm enable \&| Cm disable
+Enables or disables the recording function.
+.in -4
+.in -4
+.SH Access Control Support
+The
+.Xr ntpd 1ntpdmdoc
+daemon implements a general purpose address/mask based restriction
+list.
+The list contains address/match entries sorted first
+by increasing address values and and then by increasing mask values.
+A match occurs when the bitwise AND of the mask and the packet
+source address is equal to the bitwise AND of the mask and
+address in the list.
+The list is searched in order with the
+last match found defining the restriction flags associated
+with the entry.
+Additional information and examples can be found in the
+.Qq Notes on Configuring NTP and Setting up a NTP Subnet
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.PP
+The restriction facility was implemented in conformance
+with the access policies for the original NSFnet backbone
+time servers.
+Later the facility was expanded to deflect
+cryptographic and clogging attacks.
+While this facility may
+be useful for keeping unwanted or broken or malicious clients
+from congesting innocent servers, it should not be considered
+an alternative to the NTP authentication facilities.
+Source address based restrictions are easily circumvented
+by a determined cracker.
+.PP
+Clients can be denied service because they are explicitly
+included in the restrict list created by the restrict command
+or implicitly as the result of cryptographic or rate limit
+violations.
+Cryptographic violations include certificate
+or identity verification failure; rate limit violations generally
+result from defective NTP implementations that send packets
+at abusive rates.
+Some violations cause denied service
+only for the offending packet, others cause denied service
+for a timed period and others cause the denied service for
+an indefinate period.
+When a client or network is denied access
+for an indefinate period, the only way at present to remove
+the restrictions is by restarting the server.
+.SS The Kiss-of-Death Packet
+Ordinarily, packets denied service are simply dropped with no
+further action except incrementing statistics counters.
+Sometimes a
+more proactive response is needed, such as a server message that
+explicitly requests the client to stop sending and leave a message
+for the system operator.
+A special packet format has been created
+for this purpose called the "kiss-of-death" (KoD) packet.
+KoD packets have the leap bits set unsynchronized and stratum set
+to zero and the reference identifier field set to a four-byte
+ASCII code.
+If the
+.Cm noserve
+or
+.Cm notrust
+flag of the matching restrict list entry is set,
+the code is "DENY"; if the
+.Cm limited
+flag is set and the rate limit
+is exceeded, the code is "RATE".
+Finally, if a cryptographic violation occurs, the code is "CRYP".
+.PP
+A client receiving a KoD performs a set of sanity checks to
+minimize security exposure, then updates the stratum and
+reference identifier peer variables, sets the access
+denied (TEST4) bit in the peer flash variable and sends
+a message to the log.
+As long as the TEST4 bit is set,
+the client will send no further packets to the server.
+The only way at present to recover from this condition is
+to restart the protocol at both the client and server.
+This
+happens automatically at the client when the association times out.
+It will happen at the server only if the server operator cooperates.
+.SS Access Control Commands
+.TP
+.BR Xo Ic discard
+[ "\fIaverage\fR" "\fIavg\fR" ]
+[ "\fIminimum\fR" "\fImin\fR" ]
+[ "\fImonitor\fR" "\fIprob\fR" ]
+.Xc
+Set the parameters of the
+.Cm limited
+facility which protects the server from
+client abuse.
+The
+.Cm average
+subcommand specifies the minimum average packet
+spacing, while the
+.Cm minimum
+subcommand specifies the minimum packet spacing.
+Packets that violate these minima are discarded
+and a kiss-o'-death packet returned if enabled.
+The default
+minimum average and minimum are 5 and 2, respectively.
+The monitor subcommand specifies the probability of discard
+for packets that overflow the rate-control window.
+.TP
+.BR Xo Ic restrict address
+[ "\fImask\fR" "\fImask\fR" ]
+[ "\fIflag\fR" ... ]
+.Xc
+The
+\fIaddress\fR
+argument expressed in
+dotted-quad form is the address of a host or network.
+Alternatively, the
+\fIaddress\fR
+argument can be a valid host DNS name.
+The
+\fImask\fR
+argument expressed in dotted-quad form defaults to
+.Cm 255.255.255.255 ,
+meaning that the
+\fIaddress\fR
+is treated as the address of an individual host.
+A default entry (address
+.Cm 0.0.0.0 ,
+mask
+.Cm 0.0.0.0 )
+is always included and is always the first entry in the list.
+Note that text string
+.Cm default ,
+with no mask option, may
+be used to indicate the default entry.
+In the current implementation,
+.Cm flag
+always
+restricts access, i.e., an entry with no flags indicates that free
+access to the server is to be given.
+The flags are not orthogonal,
+in that more restrictive flags will often make less restrictive
+ones redundant.
+The flags can generally be classed into two
+categories, those which restrict time service and those which
+restrict informational queries and attempts to do run-time
+reconfiguration of the server.
+One or more of the following flags
+may be specified:
+.in +4
+.ti -4
+.IR Cm ignore
+Deny packets of all kinds, including
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+queries.
+.ti -4
+.IR Cm kod
+If this flag is set when an access violation occurs, a kiss-o'-death
+(KoD) packet is sent.
+KoD packets are rate limited to no more than one
+per second.
+If another KoD packet occurs within one second after the
+last one, the packet is dropped.
+.ti -4
+.IR Cm limited
+Deny service if the packet spacing violates the lower limits specified
+in the discard command.
+A history of clients is kept using the
+monitoring capability of
+.Xr ntpd 1ntpdmdoc .
+Thus, monitoring is always active as
+long as there is a restriction entry with the
+.Cm limited
+flag.
+.ti -4
+.IR Cm lowpriotrap
+Declare traps set by matching hosts to be low priority.
+The
+number of traps a server can maintain is limited (the current limit
+is 3).
+Traps are usually assigned on a first come, first served
+basis, with later trap requestors being denied service.
+This flag
+modifies the assignment algorithm by allowing low priority traps to
+be overridden by later requests for normal priority traps.
+.ti -4
+.IR Cm nomodify
+Deny
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+queries which attempt to modify the state of the
+server (i.e., run time reconfiguration).
+Queries which return
+information are permitted.
+.ti -4
+.IR Cm noquery
+Deny
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+queries.
+Time service is not affected.
+.ti -4
+.IR Cm nopeer
+Deny packets which would result in mobilizing a new association.
+This
+includes broadcast and symmetric active packets when a configured
+association does not exist.
+.ti -4
+.IR Cm noserve
+Deny all packets except
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+queries.
+.ti -4
+.IR Cm notrap
+Decline to provide mode 6 control message trap service to matching
+hosts.
+The trap service is a subsystem of the ntpdq control message
+protocol which is intended for use by remote event logging programs.
+.ti -4
+.IR Cm notrust
+Deny service unless the packet is cryptographically authenticated.
+.ti -4
+.IR Cm ntpport
+This is actually a match algorithm modifier, rather than a
+restriction flag.
+Its presence causes the restriction entry to be
+matched only if the source port in the packet is the standard NTP
+UDP port (123).
+Both
+.Cm ntpport
+and
+.Cm non-ntpport
+may
+be specified.
+The
+.Cm ntpport
+is considered more specific and
+is sorted later in the list.
+.ti -4
+.IR Cm version
+Deny packets that do not match the current NTP version.
+.in -4
+.PP
+Default restriction list entries with the flags ignore, interface,
+ntpport, for each of the local host's interface addresses are
+inserted into the table at startup to prevent the server
+from attempting to synchronize to its own time.
+A default entry is also always present, though if it is
+otherwise unconfigured; no flags are associated
+with the default entry (i.e., everything besides your own
+NTP server is unrestricted).
+.SH Automatic NTP Configuration Options
+.SS Manycasting
+Manycasting is a automatic discovery and configuration paradigm
+new to NTPv4.
+It is intended as a means for a multicast client
+to troll the nearby network neighborhood to find cooperating
+manycast servers, validate them using cryptographic means
+and evaluate their time values with respect to other servers
+that might be lurking in the vicinity.
+The intended result is that each manycast client mobilizes
+client associations with some number of the "best"
+of the nearby manycast servers, yet automatically reconfigures
+to sustain this number of servers should one or another fail.
+.PP
+Note that the manycasting paradigm does not coincide
+with the anycast paradigm described in RFC-1546,
+which is designed to find a single server from a clique
+of servers providing the same service.
+The manycast paradigm is designed to find a plurality
+of redundant servers satisfying defined optimality criteria.
+.PP
+Manycasting can be used with either symmetric key
+or public key cryptography.
+The public key infrastructure (PKI)
+offers the best protection against compromised keys
+and is generally considered stronger, at least with relatively
+large key sizes.
+It is implemented using the Autokey protocol and
+the OpenSSL cryptographic library available from
+.Li http://www.openssl.org/ .
+The library can also be used with other NTPv4 modes
+as well and is highly recommended, especially for broadcast modes.
+.PP
+A persistent manycast client association is configured
+using the manycastclient command, which is similar to the
+server command but with a multicast (IPv4 class
+.Cm D
+or IPv6 prefix
+.Cm FF )
+group address.
+The IANA has designated IPv4 address 224.1.1.1
+and IPv6 address FF05::101 (site local) for NTP.
+When more servers are needed, it broadcasts manycast
+client messages to this address at the minimum feasible rate
+and minimum feasible time-to-live (TTL) hops, depending
+on how many servers have already been found.
+There can be as many manycast client associations
+as different group address, each one serving as a template
+for a future ephemeral unicast client/server association.
+.PP
+Manycast servers configured with the
+.Ic manycastserver
+command listen on the specified group address for manycast
+client messages.
+Note the distinction between manycast client,
+which actively broadcasts messages, and manycast server,
+which passively responds to them.
+If a manycast server is
+in scope of the current TTL and is itself synchronized
+to a valid source and operating at a stratum level equal
+to or lower than the manycast client, it replies to the
+manycast client message with an ordinary unicast server message.
+.PP
+The manycast client receiving this message mobilizes
+an ephemeral client/server association according to the
+matching manycast client template, but only if cryptographically
+authenticated and the server stratum is less than or equal
+to the client stratum.
+Authentication is explicitly required
+and either symmetric key or public key (Autokey) can be used.
+Then, the client polls the server at its unicast address
+in burst mode in order to reliably set the host clock
+and validate the source.
+This normally results
+in a volley of eight client/server at 2-s intervals
+during which both the synchronization and cryptographic
+protocols run concurrently.
+Following the volley,
+the client runs the NTP intersection and clustering
+algorithms, which act to discard all but the "best"
+associations according to stratum and synchronization
+distance.
+The surviving associations then continue
+in ordinary client/server mode.
+.PP
+The manycast client polling strategy is designed to reduce
+as much as possible the volume of manycast client messages
+and the effects of implosion due to near-simultaneous
+arrival of manycast server messages.
+The strategy is determined by the
+.Ic manycastclient ,
+.Ic tos
+and
+.Ic ttl
+configuration commands.
+The manycast poll interval is
+normally eight times the system poll interval,
+which starts out at the
+.Cm minpoll
+value specified in the
+.Ic manycastclient ,
+command and, under normal circumstances, increments to the
+.Cm maxpolll
+value specified in this command.
+Initially, the TTL is
+set at the minimum hops specified by the ttl command.
+At each retransmission the TTL is increased until reaching
+the maximum hops specified by this command or a sufficient
+number client associations have been found.
+Further retransmissions use the same TTL.
+.PP
+The quality and reliability of the suite of associations
+discovered by the manycast client is determined by the NTP
+mitigation algorithms and the
+.Cm minclock
+and
+.Cm minsane
+values specified in the
+.Ic tos
+configuration command.
+At least
+.Cm minsane
+candidate servers must be available and the mitigation
+algorithms produce at least
+.Cm minclock
+survivors in order to synchronize the clock.
+Byzantine agreement principles require at least four
+candidates in order to correctly discard a single falseticker.
+For legacy purposes,
+.Cm minsane
+defaults to 1 and
+.Cm minclock
+defaults to 3.
+For manycast service
+.Cm minsane
+should be explicitly set to 4, assuming at least that
+number of servers are available.
+.PP
+If at least
+.Cm minclock
+servers are found, the manycast poll interval is immediately
+set to eight times
+.Cm maxpoll .
+If less than
+.Cm minclock
+servers are found when the TTL has reached the maximum hops,
+the manycast poll interval is doubled.
+For each transmission
+after that, the poll interval is doubled again until
+reaching the maximum of eight times
+.Cm maxpoll .
+Further transmissions use the same poll interval and
+TTL values.
+Note that while all this is going on,
+each client/server association found is operating normally
+it the system poll interval.
+.PP
+Administratively scoped multicast boundaries are normally
+specified by the network router configuration and,
+in the case of IPv6, the link/site scope prefix.
+By default, the increment for TTL hops is 32 starting
+from 31; however, the
+.Ic ttl
+configuration command can be
+used to modify the values to match the scope rules.
+.PP
+It is often useful to narrow the range of acceptable
+servers which can be found by manycast client associations.
+Because manycast servers respond only when the client
+stratum is equal to or greater than the server stratum,
+primary (stratum 1) servers fill find only primary servers
+in TTL range, which is probably the most common objective.
+However, unless configured otherwise, all manycast clients
+in TTL range will eventually find all primary servers
+in TTL range, which is probably not the most common
+objective in large networks.
+The
+.Ic tos
+command can be used to modify this behavior.
+Servers with stratum below
+.Cm floor
+or above
+.Cm ceiling
+specified in the
+.Ic tos
+command are strongly discouraged during the selection
+process; however, these servers may be temporally
+accepted if the number of servers within TTL range is
+less than
+.Cm minclock .
+.PP
+The above actions occur for each manycast client message,
+which repeats at the designated poll interval.
+However, once the ephemeral client association is mobilized,
+subsequent manycast server replies are discarded,
+since that would result in a duplicate association.
+If during a poll interval the number of client associations
+falls below
+.Cm minclock ,
+all manycast client prototype associations are reset
+to the initial poll interval and TTL hops and operation
+resumes from the beginning.
+It is important to avoid
+frequent manycast client messages, since each one requires
+all manycast servers in TTL range to respond.
+The result could well be an implosion, either minor or major,
+depending on the number of servers in range.
+The recommended value for
+.Cm maxpoll
+is 12 (4,096 s).
+.PP
+It is possible and frequently useful to configure a host
+as both manycast client and manycast server.
+A number of hosts configured this way and sharing a common
+group address will automatically organize themselves
+in an optimum configuration based on stratum and
+synchronization distance.
+For example, consider an NTP
+subnet of two primary servers and a hundred or more
+dependent clients.
+With two exceptions, all servers
+and clients have identical configuration files including both
+.Ic multicastclient
+and
+.Ic multicastserver
+commands using, for instance, multicast group address
+239.1.1.1.
+The only exception is that each primary server
+configuration file must include commands for the primary
+reference source such as a GPS receiver.
+.PP
+The remaining configuration files for all secondary
+servers and clients have the same contents, except for the
+.Ic tos
+command, which is specific for each stratum level.
+For stratum 1 and stratum 2 servers, that command is
+not necessary.
+For stratum 3 and above servers the
+.Cm floor
+value is set to the intended stratum number.
+Thus, all stratum 3 configuration files are identical,
+all stratum 4 files are identical and so forth.
+.PP
+Once operations have stabilized in this scenario,
+the primary servers will find the primary reference source
+and each other, since they both operate at the same
+stratum (1), but not with any secondary server or client,
+since these operate at a higher stratum.
+The secondary
+servers will find the servers at the same stratum level.
+If one of the primary servers loses its GPS receiver,
+it will continue to operate as a client and other clients
+will time out the corresponding association and
+re-associate accordingly.
+.PP
+Some administrators prefer to avoid running
+.Xr ntpd 1ntpdmdoc
+continuously and run either
+.Xr ntpdate 8
+or
+.Xr ntpd 1ntpdmdoc
+q
+as a cron job.
+In either case the servers must be
+configured in advance and the program fails if none are
+available when the cron job runs.
+A really slick
+application of manycast is with
+.Xr ntpd 1ntpdmdoc
+q .
+The program wakes up, scans the local landscape looking
+for the usual suspects, selects the best from among
+the rascals, sets the clock and then departs.
+Servers do not have to be configured in advance and
+all clients throughout the network can have the same
+configuration file.
+.SS Manycast Interactions with Autokey
+Each time a manycast client sends a client mode packet
+to a multicast group address, all manycast servers
+in scope generate a reply including the host name
+and status word.
+The manycast clients then run
+the Autokey protocol, which collects and verifies
+all certificates involved.
+Following the burst interval
+all but three survivors are cast off,
+but the certificates remain in the local cache.
+It often happens that several complete signing trails
+from the client to the primary servers are collected in this way.
+.PP
+About once an hour or less often if the poll interval
+exceeds this, the client regenerates the Autokey key list.
+This is in general transparent in client/server mode.
+However, about once per day the server private value
+used to generate cookies is refreshed along with all
+manycast client associations.
+In this case all
+cryptographic values including certificates is refreshed.
+If a new certificate has been generated since
+the last refresh epoch, it will automatically revoke
+all prior certificates that happen to be in the
+certificate cache.
+At the same time, the manycast
+scheme starts all over from the beginning and
+the expanding ring shrinks to the minimum and increments
+from there while collecting all servers in scope.
+.SS Manycast Options
+.TP
+.BR Xo Ic tos
+.Oo
+.Cm ceiling Ar ceiling |
+.Cm cohort { 0 | 1 } |
+.Cm floor Ar floor |
+.Cm minclock Ar minclock |
+.Cm minsane Ar minsane
+.Oc
+.Xc
+This command affects the clock selection and clustering
+algorithms.
+It can be used to select the quality and
+quantity of peers used to synchronize the system clock
+and is most useful in manycast mode.
+The variables operate
+as follows:
+.in +4
+.ti -4
+.IR Cm ceiling Ar ceiling
+Peers with strata above
+.Cm ceiling
+will be discarded if there are at least
+.Cm minclock
+peers remaining.
+This value defaults to 15, but can be changed
+to any number from 1 to 15.
+.ti -4
+.IR Cm cohort Bro 0 | 1 Brc
+This is a binary flag which enables (0) or disables (1)
+manycast server replies to manycast clients with the same
+stratum level.
+This is useful to reduce implosions where
+large numbers of clients with the same stratum level
+are present.
+The default is to enable these replies.
+.ti -4
+.IR Cm floor Ar floor
+Peers with strata below
+.Cm floor
+will be discarded if there are at least
+.Cm minclock
+peers remaining.
+This value defaults to 1, but can be changed
+to any number from 1 to 15.
+.ti -4
+.IR Cm minclock Ar minclock
+The clustering algorithm repeatedly casts out outlyer
+associations until no more than
+.Cm minclock
+associations remain.
+This value defaults to 3,
+but can be changed to any number from 1 to the number of
+configured sources.
+.ti -4
+.IR Cm minsane Ar minsane
+This is the minimum number of candidates available
+to the clock selection algorithm in order to produce
+one or more truechimers for the clustering algorithm.
+If fewer than this number are available, the clock is
+undisciplined and allowed to run free.
+The default is 1
+for legacy purposes.
+However, according to principles of
+Byzantine agreement,
+.Cm minsane
+should be at least 4 in order to detect and discard
+a single falseticker.
+.in -4
+.TP
+.BR Cm ttl Ar hop ...
+This command specifies a list of TTL values in increasing
+order, up to 8 values can be specified.
+In manycast mode these values are used in turn
+in an expanding-ring search.
+The default is eight
+multiples of 32 starting at 31.
+.SH Reference Clock Support
+The NTP Version 4 daemon supports some three dozen different radio,
+satellite and modem reference clocks plus a special pseudo-clock
+used for backup or when no other clock source is available.
+Detailed descriptions of individual device drivers and options can
+be found in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+Additional information can be found in the pages linked
+there, including the
+.Qq Debugging Hints for Reference Clock Drivers
+and
+.Qq How To Write a Reference Clock Driver
+pages
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+In addition, support for a PPS
+signal is available as described in the
+.Qq Pulse-per-second (PPS) Signal Interfacing
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+Many
+drivers support special line discipline/streams modules which can
+significantly improve the accuracy using the driver.
+These are
+described in the
+.Qq Line Disciplines and Streams Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.PP
+A reference clock will generally (though not always) be a radio
+timecode receiver which is synchronized to a source of standard
+time such as the services offered by the NRC in Canada and NIST and
+USNO in the US.
+The interface between the computer and the timecode
+receiver is device dependent, but is usually a serial port.
+A
+device driver specific to each reference clock must be selected and
+compiled in the distribution; however, most common radio, satellite
+and modem clocks are included by default.
+Note that an attempt to
+configure a reference clock when the driver has not been compiled
+or the hardware port has not been appropriately configured results
+in a scalding remark to the system log file, but is otherwise non
+hazardous.
+.PP
+For the purposes of configuration,
+.Xr ntpd 1ntpdmdoc
+treats
+reference clocks in a manner analogous to normal NTP peers as much
+as possible.
+Reference clocks are identified by a syntactically
+correct but invalid IP address, in order to distinguish them from
+normal NTP peers.
+Reference clock addresses are of the form
+.Sm off
+.Li 127.127. Ar t . Ar u ,
+.Sm on
+where
+\fIt\fR
+is an integer
+denoting the clock type and
+\fIu\fR
+indicates the unit
+number in the range 0-3.
+While it may seem overkill, it is in fact
+sometimes useful to configure multiple reference clocks of the same
+type, in which case the unit numbers must be unique.
+.PP
+The
+.Ic server
+command is used to configure a reference
+clock, where the
+\fIaddress\fR
+argument in that command
+is the clock address.
+The
+.Cm key ,
+.Cm version
+and
+.Cm ttl
+options are not used for reference clock support.
+The
+.Cm mode
+option is added for reference clock support, as
+described below.
+The
+.Cm prefer
+option can be useful to
+persuade the server to cherish a reference clock with somewhat more
+enthusiasm than other reference clocks or peers.
+Further
+information on this option can be found in the
+.Qq Mitigation Rules and the prefer Keyword
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page.
+The
+.Cm minpoll
+and
+.Cm maxpoll
+options have
+meaning only for selected clock drivers.
+See the individual clock
+driver document pages for additional information.
+.PP
+The
+.Ic fudge
+command is used to provide additional
+information for individual clock drivers and normally follows
+immediately after the
+.Ic server
+command.
+The
+\fIaddress\fR
+argument specifies the clock address.
+The
+.Cm refid
+and
+.Cm stratum
+options can be used to
+override the defaults for the device.
+There are two optional
+device-dependent time offsets and four flags that can be included
+in the
+.Ic fudge
+command as well.
+.PP
+The stratum number of a reference clock is by default zero.
+Since the
+.Xr ntpd 1ntpdmdoc
+daemon adds one to the stratum of each
+peer, a primary server ordinarily displays an external stratum of
+one.
+In order to provide engineered backups, it is often useful to
+specify the reference clock stratum as greater than zero.
+The
+.Cm stratum
+option is used for this purpose.
+Also, in cases
+involving both a reference clock and a pulse-per-second (PPS)
+discipline signal, it is useful to specify the reference clock
+identifier as other than the default, depending on the driver.
+The
+.Cm refid
+option is used for this purpose.
+Except where noted,
+these options apply to all clock drivers.
+.SS Reference Clock Commands
+.TP
+.BR Xo Ic server
+.Sm off
+.Li 127.127. Ar t . Ar u
+.Sm on
+[ "\fIprefer\fR" ]
+[ "\fImode\fR" "\fIint\fR" ]
+[ "\fIminpoll\fR" "\fIint\fR" ]
+[ "\fImaxpoll\fR" "\fIint\fR" ]
+.Xc
+This command can be used to configure reference clocks in
+special ways.
+The options are interpreted as follows:
+.in +4
+.ti -4
+.IR Cm prefer
+Marks the reference clock as preferred.
+All other things being
+equal, this host will be chosen for synchronization among a set of
+correctly operating hosts.
+See the
+.Qq Mitigation Rules and the prefer Keyword
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+for further information.
+.ti -4
+.IR Cm mode Ar int
+Specifies a mode number which is interpreted in a
+device-specific fashion.
+For instance, it selects a dialing
+protocol in the ACTS driver and a device subtype in the
+parse
+drivers.
+.ti -4
+.IR Cm minpoll Ar int
+.ti -4
+.IR Cm maxpoll Ar int
+These options specify the minimum and maximum polling interval
+for reference clock messages, as a power of 2 in seconds
+For
+most directly connected reference clocks, both
+.Cm minpoll
+and
+.Cm maxpoll
+default to 6 (64 s).
+For modem reference clocks,
+.Cm minpoll
+defaults to 10 (17.1 m) and
+.Cm maxpoll
+defaults to 14 (4.5 h).
+The allowable range is 4 (16 s) to 17 (36.4 h) inclusive.
+.in -4
+.TP
+.BR Xo Ic fudge
+.Sm off
+.Li 127.127. Ar t . Ar u
+.Sm on
+[ "\fItime1\fR" "\fIsec\fR" ]
+[ "\fItime2\fR" "\fIsec\fR" ]
+[ "\fIstratum\fR" "\fIint\fR" ]
+[ "\fIrefid\fR" "\fIstring\fR" ]
+[ "\fImode\fR" "\fIint\fR" ]
+[ "\fIflag1\fR" "\fI0\fR" \&| "\fI1\fR" ]
+[ "\fIflag2\fR" "\fI0\fR" \&| "\fI1\fR" ]
+[ "\fIflag3\fR" "\fI0\fR" \&| "\fI1\fR" ]
+[ "\fIflag4\fR" "\fI0\fR" \&| "\fI1\fR" ]
+.Xc
+This command can be used to configure reference clocks in
+special ways.
+It must immediately follow the
+.Ic server
+command which configures the driver.
+Note that the same capability
+is possible at run time using the
+.Xr ntpdc 1ntpdcmdoc
+program.
+The options are interpreted as
+follows:
+.in +4
+.ti -4
+.IR Cm time1 Ar sec
+Specifies a constant to be added to the time offset produced by
+the driver, a fixed-point decimal number in seconds.
+This is used
+as a calibration constant to adjust the nominal time offset of a
+particular clock to agree with an external standard, such as a
+precision PPS signal.
+It also provides a way to correct a
+systematic error or bias due to serial port or operating system
+latencies, different cable lengths or receiver internal delay.
+The
+specified offset is in addition to the propagation delay provided
+by other means, such as internal DIPswitches.
+Where a calibration
+for an individual system and driver is available, an approximate
+correction is noted in the driver documentation pages.
+Note: in order to facilitate calibration when more than one
+radio clock or PPS signal is supported, a special calibration
+feature is available.
+It takes the form of an argument to the
+.Ic enable
+command described in
+.Sx Miscellaneous Options
+page and operates as described in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.ti -4
+.IR Cm time2 Ar secs
+Specifies a fixed-point decimal number in seconds, which is
+interpreted in a driver-dependent way.
+See the descriptions of
+specific drivers in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.ti -4
+.IR Cm stratum Ar int
+Specifies the stratum number assigned to the driver, an integer
+between 0 and 15.
+This number overrides the default stratum number
+ordinarily assigned by the driver itself, usually zero.
+.ti -4
+.IR Cm refid Ar string
+Specifies an ASCII string of from one to four characters which
+defines the reference identifier used by the driver.
+This string
+overrides the default identifier ordinarily assigned by the driver
+itself.
+.ti -4
+.IR Cm mode Ar int
+Specifies a mode number which is interpreted in a
+device-specific fashion.
+For instance, it selects a dialing
+protocol in the ACTS driver and a device subtype in the
+parse
+drivers.
+.ti -4
+.IR Cm flag1 Cm 0 \&| Cm 1
+.ti -4
+.IR Cm flag2 Cm 0 \&| Cm 1
+.ti -4
+.IR Cm flag3 Cm 0 \&| Cm 1
+.ti -4
+.IR Cm flag4 Cm 0 \&| Cm 1
+These four flags are used for customizing the clock driver.
+The
+interpretation of these values, and whether they are used at all,
+is a function of the particular clock driver.
+However, by
+convention
+.Cm flag4
+is used to enable recording monitoring
+data to the
+.Cm clockstats
+file configured with the
+.Ic filegen
+command.
+Further information on the
+.Ic filegen
+command can be found in
+.Sx Monitoring Options .
+.in -4
+.SH Miscellaneous Options
+.TP
+.BR Ic broadcastdelay Ar seconds
+The broadcast and multicast modes require a special calibration
+to determine the network delay between the local and remote
+servers.
+Ordinarily, this is done automatically by the initial
+protocol exchanges between the client and server.
+In some cases,
+the calibration procedure may fail due to network or server access
+controls, for example.
+This command specifies the default delay to
+be used under these circumstances.
+Typically (for Ethernet), a
+number between 0.003 and 0.007 seconds is appropriate.
+The default
+when this command is not used is 0.004 seconds.
+.TP
+.BR Ic calldelay Ar delay
+This option controls the delay in seconds between the first and second
+packets sent in burst or iburst mode to allow additional time for a modem
+or ISDN call to complete.
+.TP
+.BR Ic driftfile Ar driftfile
+This command specifies the complete path and name of the file used to
+record the frequency of the local clock oscillator.
+This is the same
+operation as the
+f
+command line option.
+If the file exists, it is read at
+startup in order to set the initial frequency and then updated once per
+hour with the current frequency computed by the daemon.
+If the file name is
+specified, but the file itself does not exist, the starts with an initial
+frequency of zero and creates the file when writing it for the first time.
+If this command is not given, the daemon will always start with an initial
+frequency of zero.
+.PP
+The file format consists of a single line containing a single
+floating point number, which records the frequency offset measured
+in parts-per-million (PPM).
+The file is updated by first writing
+the current drift value into a temporary file and then renaming
+this file to replace the old version.
+This implies that
+.Xr ntpd 1ntpdmdoc
+must have write permission for the directory the
+drift file is located in, and that file system links, symbolic or
+otherwise, should be avoided.
+.TP
+.BR Xo Ic enable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+.TP
+.BR Xo Ic disable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+Provides a way to enable or disable various server options.
+Flags not mentioned are unaffected.
+Note that all of these flags
+can be controlled remotely using the
+.Xr ntpdc 1ntpdcmdoc
+utility program.
+.in +4
+.ti -4
+.IR Cm auth
+Enables the server to synchronize with unconfigured peers only if the
+peer has been correctly authenticated using either public key or
+private key cryptography.
+The default for this flag is
+.Ic enable .
+.ti -4
+.IR Cm bclient
+Enables the server to listen for a message from a broadcast or
+multicast server, as in the
+.Ic multicastclient
+command with default
+address.
+The default for this flag is
+.Ic disable .
+.ti -4
+.IR Cm calibrate
+Enables the calibrate feature for reference clocks.
+The default for
+this flag is
+.Ic disable .
+.ti -4
+.IR Cm kernel
+Enables the kernel time discipline, if available.
+The default for this
+flag is
+.Ic enable
+if support is available, otherwise
+.Ic disable .
+.ti -4
+.IR Cm monitor
+Enables the monitoring facility.
+See the
+.Xr ntpdc 1ntpdcmdoc
+program
+and the
+.Ic monlist
+command or further information.
+The
+default for this flag is
+.Ic enable .
+.ti -4
+.IR Cm ntp
+Enables time and frequency discipline.
+In effect, this switch opens and
+closes the feedback loop, which is useful for testing.
+The default for
+this flag is
+.Ic enable .
+.ti -4
+.IR Cm pps
+Enables the pulse-per-second (PPS) signal when frequency and time is
+disciplined by the precision time kernel modifications.
+See the
+.Qq A Kernel Model for Precision Timekeeping
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page for further information.
+The default for this flag is
+.Ic disable .
+.ti -4
+.IR Cm stats
+Enables the statistics facility.
+See the
+.Sx Monitoring Options
+section for further information.
+The default for this flag is
+.Ic disable .
+.in -4
+.TP
+.BR Ic includefile Ar includefile
+This command allows additional configuration commands
+to be included from a separate file.
+Include files may
+be nested to a depth of five; upon reaching the end of any
+include file, command processing resumes in the previous
+configuration file.
+This option is useful for sites that run
+.Xr ntpd 1ntpdmdoc
+on multiple hosts, with (mostly) common options (e.g., a
+restriction list).
+.TP
+.BR Ic logconfig Ar configkeyword
+This command controls the amount and type of output written to
+the system
+.Xr syslog 3
+facility or the alternate
+.Ic logfile
+log file.
+By default, all output is turned on.
+All
+\fIconfigkeyword\fR
+keywords can be prefixed with
+.Ql = ,
+.Ql +
+and
+.Ql - ,
+where
+.Ql =
+sets the
+.Xr syslog 3
+priority mask,
+.Ql +
+adds and
+.Ql -
+removes
+messages.
+.Xr syslog 3
+messages can be controlled in four
+classes
+.Po
+.Cm clock ,
+.Cm peer ,
+.Cm sys
+and
+.Cm sync
+.Pc .
+Within these classes four types of messages can be
+controlled: informational messages
+.Po
+.Cm info
+.Pc ,
+event messages
+.Po
+.Cm events
+.Pc ,
+statistics messages
+.Po
+.Cm statistics
+.Pc
+and
+status messages
+.Po
+.Cm status
+.Pc .
+.PP
+Configuration keywords are formed by concatenating the message class with
+the event class.
+The
+.Cm all
+prefix can be used instead of a message class.
+A
+message class may also be followed by the
+.Cm all
+keyword to enable/disable all
+messages of the respective message class.Thus, a minimal log configuration
+could look like this:
+.br
+.in +4
+.nf
+logconfig =syncstatus +sysevents
+.in -4
+.fi
+.PP
+This would just list the synchronizations state of
+.Xr ntpd 1ntpdmdoc
+and the major system events.
+For a simple reference server, the
+following minimum message configuration could be useful:
+.br
+.in +4
+.nf
+logconfig =syncall +clockall
+.in -4
+.fi
+.PP
+This configuration will list all clock information and
+synchronization information.
+All other events and messages about
+peers, system events and so on is suppressed.
+.TP
+.BR Ic logfile Ar logfile
+This command specifies the location of an alternate log file to
+be used instead of the default system
+.Xr syslog 3
+facility.
+This is the same operation as the -l command line option.
+.TP
+.BR Ic setvar Ar variable Op Cm default
+This command adds an additional system variable.
+These
+variables can be used to distribute additional information such as
+the access policy.
+If the variable of the form
+.Sm off
+.Va name = Ar value
+.Sm on
+is followed by the
+.Cm default
+keyword, the
+variable will be listed as part of the default system variables
+.Po
+.Xr ntpq 1ntpqmdoc
+.Ic rv
+command
+.Pc ) .
+These additional variables serve
+informational purposes only.
+They are not related to the protocol
+other that they can be listed.
+The known protocol variables will
+always override any variables defined via the
+.Ic setvar
+mechanism.
+There are three special variables that contain the names
+of all variable of the same group.
+The
+.Va sys_var_list
+holds
+the names of all system variables.
+The
+.Va peer_var_list
+holds
+the names of all peer variables and the
+.Va clock_var_list
+holds the names of the reference clock variables.
+.TP
+.BR Xo Ic tinker
+.Oo
+.Cm allan Ar allan |
+.Cm dispersion Ar dispersion |
+.Cm freq Ar freq |
+.Cm huffpuff Ar huffpuff |
+.Cm panic Ar panic |
+.Cm step Ar srep |
+.Cm stepout Ar stepout
+.Oc
+.Xc
+This command can be used to alter several system variables in
+very exceptional circumstances.
+It should occur in the
+configuration file before any other configuration options.
+The
+default values of these variables have been carefully optimized for
+a wide range of network speeds and reliability expectations.
+In
+general, they interact in intricate ways that are hard to predict
+and some combinations can result in some very nasty behavior.
+Very
+rarely is it necessary to change the default values; but, some
+folks cannot resist twisting the knobs anyway and this command is
+for them.
+Emphasis added: twisters are on their own and can expect
+no help from the support group.
+.PP
+The variables operate as follows:
+.in +4
+.ti -4
+.IR Cm allan Ar allan
+The argument becomes the new value for the minimum Allan
+intercept, which is a parameter of the PLL/FLL clock discipline
+algorithm.
+The value in log2 seconds defaults to 7 (1024 s), which is also the lower
+limit.
+.ti -4
+.IR Cm dispersion Ar dispersion
+The argument becomes the new value for the dispersion increase rate,
+normally .000015 s/s.
+.ti -4
+.IR Cm freq Ar freq
+The argument becomes the initial value of the frequency offset in
+parts-per-million.
+This overrides the value in the frequency file, if
+present, and avoids the initial training state if it is not.
+.ti -4
+.IR Cm huffpuff Ar huffpuff
+The argument becomes the new value for the experimental
+huff-n'-puff filter span, which determines the most recent interval
+the algorithm will search for a minimum delay.
+The lower limit is
+900 s (15 m), but a more reasonable value is 7200 (2 hours).
+There
+is no default, since the filter is not enabled unless this command
+is given.
+.ti -4
+.IR Cm panic Ar panic
+The argument is the panic threshold, normally 1000 s.
+If set to zero,
+the panic sanity check is disabled and a clock offset of any value will
+be accepted.
+.ti -4
+.IR Cm step Ar step
+The argument is the step threshold, which by default is 0.128 s.
+It can
+be set to any positive number in seconds.
+If set to zero, step
+adjustments will never occur.
+Note: The kernel time discipline is
+disabled if the step threshold is set to zero or greater than the
+default.
+.ti -4
+.IR Cm stepout Ar stepout
+The argument is the stepout timeout, which by default is 900 s.
+It can
+be set to any positive number in seconds.
+If set to zero, the stepout
+pulses will not be suppressed.
+.in -4
+.TP
+.BR Xo Ic trap Ar host_address
+[ "\fIport\fR" "\fIport_number\fR" ]
+[ "\fIinterface\fR" "\fIinterface_address\fR" ]
+.Xc
+This command configures a trap receiver at the given host
+address and port number for sending messages with the specified
+local interface address.
+If the port number is unspecified, a value
+of 18447 is used.
+If the interface address is not specified, the
+message is sent with a source address of the local interface the
+message is sent through.
+Note that on a multihomed host the
+interface used may vary from time to time with routing changes.
+.PP
+The trap receiver will generally log event messages and other
+information from the server in a log file.
+While such monitor
+programs may also request their own trap dynamically, configuring a
+trap receiver will ensure that no messages are lost when the server
+is started.
+.TP
+.BR Cm hop Ar ...
+This command specifies a list of TTL values in increasing order, up to 8
+values can be specified.
+In manycast mode these values are used in turn in
+an expanding-ring search.
+The default is eight multiples of 32 starting at
+31.
.SH FILES
+.TP
+.BR Pa /etc/ntp.conf
+the default name of the configuration file
+.TP
+.BR Pa ntp.keys
+private MD5 keys
+.TP
+.BR Pa ntpkey
+RSA private key
+.TP
+.BR Pa ntpkey_ Ns Ar host
+RSA public key
+.TP
+.BR Pa ntp_dh
+Diffie-Hellman agreement parameters
.SH "SEE ALSO"
+.SH SEE ALSO
+.Xr ntpd 1ntpdmdoc ,
+.Xr ntpdc 1ntpdcmdoc ,
+.Xr ntpq 1ntpqmdoc
+.PP
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+.Li http://www.ntp.org/ .
+A snapshot of this documentation is available in HTML format in
+.Pa /usr/share/doc/ntp .
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 4)
+.%O RFC5905
+.Re
.SH "AUTHORS"
The University of Delaware
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The syntax checking is not picky; some combinations of
+ridiculous and even hilarious options and modes may not be
+detected.
+.PP
+The
+.Pa ntpkey_ Ns Ar host
+files are really digital
+certificates.
+These should be obtained via secure directory
+services when they become universally available.Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntp.conf\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTP_CONF 5mdoc File Formats
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntp.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:19:44 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:31 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp.conf.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
All arguments must be options.
.Pp
.Sh DESCRIPTION
+The
+.Nm
+configuration file is read at initial startup by the
+.Xr ntpd 1ntpdmdoc
+daemon in order to specify the synchronization sources,
+modes and other related information.
+Usually, it is installed in the
+.Pa /etc
+directory,
+but could be installed elsewhere
+(see the daemon's
+.Fl c
+command line option).
+.Pp
+The file format is similar to other
+.Ux
+configuration files.
+Comments begin with a
+.Ql #
+character and extend to the end of the line;
+blank lines are ignored.
+Configuration commands consist of an initial keyword
+followed by a list of arguments,
+some of which may be optional, separated by whitespace.
+Commands may not be continued over multiple lines.
+Arguments may be host names,
+host addresses written in numeric, dotted-quad form,
+integers, floating point numbers (when specifying times in seconds)
+and text strings.
+.Pp
+The rest of this page describes the configuration and control options.
+The
+.Qq Notes on Configuring NTP and Setting up an NTP Subnet
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+contains an extended discussion of these options.
+In addition to the discussion of general
+.Sx Configuration Options ,
+there are sections describing the following supported functionality
+and the options used to control it:
+.Bl -bullet -offset indent
+.It
+.Sx Authentication Support
+.It
+.Sx Monitoring Support
+.It
+.Sx Access Control Support
+.It
+.Sx Automatic NTP Configuration Options
+.It
+.Sx Reference Clock Support
+.It
+.Sx Miscellaneous Options
+.El
+.Pp
+Following these is a section describing
+.Sx Miscellaneous Options .
+While there is a rich set of options available,
+the only required option is one or more
+.Ic pool ,
+.Ic server ,
+.Ic peer ,
+.Ic broadcast
+or
+.Ic manycastclient
+commands.
+.Sh Configuration Support
+Following is a description of the configuration commands in
+NTPv4.
+These commands have the same basic functions as in NTPv3 and
+in some cases new functions and new arguments.
+There are two
+classes of commands, configuration commands that configure a
+persistent association with a remote server or peer or reference
+clock, and auxiliary commands that specify environmental variables
+that control various related operations.
+.Ss Configuration Commands
+The various modes are determined by the command keyword and the
+type of the required IP address.
+Addresses are classed by type as
+(s) a remote server or peer (IPv4 class A, B and C), (b) the
+broadcast address of a local interface, (m) a multicast address (IPv4
+class D), or (r) a reference clock address (127.127.x.x).
+Note that
+only those options applicable to each command are listed below.
+Use
+of options not listed may not be caught as an error, but may result
+in some weird and even destructive behavior.
+.Pp
+If the Basic Socket Interface Extensions for IPv6 (RFC-2553)
+is detected, support for the IPv6 address family is generated
+in addition to the default support of the IPv4 address family.
+In a few cases, including the reslist billboard generated
+by ntpdc, IPv6 addresses are automatically generated.
+IPv6 addresses can be identified by the presence of colons
+.Dq \&:
+in the address field.
+IPv6 addresses can be used almost everywhere where
+IPv4 addresses can be used,
+with the exception of reference clock addresses,
+which are always IPv4.
+.Pp
+Note that in contexts where a host name is expected, a
+.Fl 4
+qualifier preceding
+the host name forces DNS resolution to the IPv4 namespace,
+while a
+.Fl 6
+qualifier forces DNS resolution to the IPv6 namespace.
+See IPv6 references for the
+equivalent classes for that address family.
+.Bl -tag -width indent
+.It Xo Ic pool Ar address
+.Op Cm burst
+.Op Cm iburst
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm maxpoll Ar maxpoll
+.Xc
+.It Xo Ic server Ar address
+.Op Cm key Ar key \&| Cm autokey
+.Op Cm burst
+.Op Cm iburst
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm maxpoll Ar maxpoll
+.Xc
+.It Xo Ic peer Ar address
+.Op Cm key Ar key \&| Cm autokey
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm maxpoll Ar maxpoll
+.Xc
+.It Xo Ic broadcast Ar address
+.Op Cm key Ar key \&| Cm autokey
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm ttl Ar ttl
+.Xc
+.It Xo Ic manycastclient Ar address
+.Op Cm key Ar key \&| Cm autokey
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm maxpoll Ar maxpoll
+.Op Cm ttl Ar ttl
+.Xc
+.El
+.Pp
+These five commands specify the time server name or address to
+be used and the mode in which to operate.
+The
+.Ar address
+can be
+either a DNS name or an IP address in dotted-quad notation.
+Additional information on association behavior can be found in the
+.Qq Association Management
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.Bl -tag -width indent
+.It Ic pool
+For type s addresses, this command mobilizes a persistent
+client mode association with a number of remote servers.
+In this mode the local clock can synchronized to the
+remote server, but the remote server can never be synchronized to
+the local clock.
+.It Ic server
+For type s and r addresses, this command mobilizes a persistent
+client mode association with the specified remote server or local
+radio clock.
+In this mode the local clock can synchronized to the
+remote server, but the remote server can never be synchronized to
+the local clock.
+This command should
+.Em not
+be used for type
+b or m addresses.
+.It Ic peer
+For type s addresses (only), this command mobilizes a
+persistent symmetric-active mode association with the specified
+remote peer.
+In this mode the local clock can be synchronized to
+the remote peer or the remote peer can be synchronized to the local
+clock.
+This is useful in a network of servers where, depending on
+various failure scenarios, either the local or remote peer may be
+the better source of time.
+This command should NOT be used for type
+b, m or r addresses.
+.It Ic broadcast
+For type b and m addresses (only), this
+command mobilizes a persistent broadcast mode association.
+Multiple
+commands can be used to specify multiple local broadcast interfaces
+(subnets) and/or multiple multicast groups.
+Note that local
+broadcast messages go only to the interface associated with the
+subnet specified, but multicast messages go to all interfaces.
+In broadcast mode the local server sends periodic broadcast
+messages to a client population at the
+.Ar address
+specified, which is usually the broadcast address on (one of) the
+local network(s) or a multicast address assigned to NTP.
+The IANA
+has assigned the multicast group address IPv4 224.0.1.1 and
+IPv6 ff05::101 (site local) exclusively to
+NTP, but other nonconflicting addresses can be used to contain the
+messages within administrative boundaries.
+Ordinarily, this
+specification applies only to the local server operating as a
+sender; for operation as a broadcast client, see the
+.Ic broadcastclient
+or
+.Ic multicastclient
+commands
+below.
+.It Ic manycastclient
+For type m addresses (only), this command mobilizes a
+manycast client mode association for the multicast address
+specified.
+In this case a specific address must be supplied which
+matches the address used on the
+.Ic manycastserver
+command for
+the designated manycast servers.
+The NTP multicast address
+224.0.1.1 assigned by the IANA should NOT be used, unless specific
+means are taken to avoid spraying large areas of the Internet with
+these messages and causing a possibly massive implosion of replies
+at the sender.
+The
+.Ic manycastserver
+command specifies that the local server
+is to operate in client mode with the remote servers that are
+discovered as the result of broadcast/multicast messages.
+The
+client broadcasts a request message to the group address associated
+with the specified
+.Ar address
+and specifically enabled
+servers respond to these messages.
+The client selects the servers
+providing the best time and continues as with the
+.Ic server
+command.
+The remaining servers are discarded as if never
+heard.
+.El
+.Pp
+Options:
+.Bl -tag -width indent
+.It Cm autokey
+All packets sent to and received from the server or peer are to
+include authentication fields encrypted using the autokey scheme
+described in
+.Sx Authentication Options .
+.It Cm burst
+when the server is reachable, send a burst of eight packets
+instead of the usual one.
+The packet spacing is normally 2 s;
+however, the spacing between the first and second packets
+can be changed with the calldelay command to allow
+additional time for a modem or ISDN call to complete.
+This is designed to improve timekeeping quality
+with the
+.Ic server
+command and s addresses.
+.It Cm iburst
+When the server is unreachable, send a burst of eight packets
+instead of the usual one.
+The packet spacing is normally 2 s;
+however, the spacing between the first two packets can be
+changed with the calldelay command to allow
+additional time for a modem or ISDN call to complete.
+This is designed to speed the initial synchronization
+acquisition with the
+.Ic server
+command and s addresses and when
+.Xr ntpd 1ntpdmdoc
+is started with the
+.Fl q
+option.
+.It Cm key Ar key
+All packets sent to and received from the server or peer are to
+include authentication fields encrypted using the specified
+.Ar key
+identifier with values from 1 to 65534, inclusive.
+The
+default is to include no encryption field.
+.It Cm minpoll Ar minpoll
+.It Cm maxpoll Ar maxpoll
+These options specify the minimum and maximum poll intervals
+for NTP messages, as a power of 2 in seconds
+The maximum poll
+interval defaults to 10 (1,024 s), but can be increased by the
+.Cm maxpoll
+option to an upper limit of 17 (36.4 h).
+The
+minimum poll interval defaults to 6 (64 s), but can be decreased by
+the
+.Cm minpoll
+option to a lower limit of 4 (16 s).
+.It Cm noselect
+Marks the server as unused, except for display purposes.
+The server is discarded by the selection algroithm.
+.It Cm prefer
+Marks the server as preferred.
+All other things being equal,
+this host will be chosen for synchronization among a set of
+correctly operating hosts.
+See the
+.Qq Mitigation Rules and the prefer Keyword
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+for further information.
+.It Cm ttl Ar ttl
+This option is used only with broadcast server and manycast
+client modes.
+It specifies the time-to-live
+.Ar ttl
+to
+use on broadcast server and multicast server and the maximum
+.Ar ttl
+for the expanding ring search with manycast
+client packets.
+Selection of the proper value, which defaults to
+127, is something of a black art and should be coordinated with the
+network administrator.
+.It Cm version Ar version
+Specifies the version number to be used for outgoing NTP
+packets.
+Versions 1-4 are the choices, with version 4 the
+default.
+.El
+.Ss Auxiliary Commands
+.Bl -tag -width indent
+.It Ic broadcastclient
+This command enables reception of broadcast server messages to
+any local interface (type b) address.
+Upon receiving a message for
+the first time, the broadcast client measures the nominal server
+propagation delay using a brief client/server exchange with the
+server, then enters the broadcast client mode, in which it
+synchronizes to succeeding broadcast messages.
+Note that, in order
+to avoid accidental or malicious disruption in this mode, both the
+server and client should operate using symmetric-key or public-key
+authentication as described in
+.Sx Authentication Options .
+.It Ic manycastserver Ar address ...
+This command enables reception of manycast client messages to
+the multicast group address(es) (type m) specified.
+At least one
+address is required, but the NTP multicast address 224.0.1.1
+assigned by the IANA should NOT be used, unless specific means are
+taken to limit the span of the reply and avoid a possibly massive
+implosion at the original sender.
+Note that, in order to avoid
+accidental or malicious disruption in this mode, both the server
+and client should operate using symmetric-key or public-key
+authentication as described in
+.Sx Authentication Options .
+.It Ic multicastclient Ar address ...
+This command enables reception of multicast server messages to
+the multicast group address(es) (type m) specified.
+Upon receiving
+a message for the first time, the multicast client measures the
+nominal server propagation delay using a brief client/server
+exchange with the server, then enters the broadcast client mode, in
+which it synchronizes to succeeding multicast messages.
+Note that,
+in order to avoid accidental or malicious disruption in this mode,
+both the server and client should operate using symmetric-key or
+public-key authentication as described in
+.Sx Authentication Options .
+.El
+.Sh Authentication Support
+Authentication support allows the NTP client to verify that the
+server is in fact known and trusted and not an intruder intending
+accidentally or on purpose to masquerade as that server.
+The NTPv3
+specification RFC-1305 defines a scheme which provides
+cryptographic authentication of received NTP packets.
+Originally,
+this was done using the Data Encryption Standard (DES) algorithm
+operating in Cipher Block Chaining (CBC) mode, commonly called
+DES-CBC.
+Subsequently, this was replaced by the RSA Message Digest
+5 (MD5) algorithm using a private key, commonly called keyed-MD5.
+Either algorithm computes a message digest, or one-way hash, which
+can be used to verify the server has the correct private key and
+key identifier.
+.Pp
+NTPv4 retains the NTPv3 scheme, properly described as symmetric key
+cryptography and, in addition, provides a new Autokey scheme
+based on public key cryptography.
+Public key cryptography is generally considered more secure
+than symmetric key cryptography, since the security is based
+on a private value which is generated by each server and
+never revealed.
+With Autokey all key distribution and
+management functions involve only public values, which
+considerably simplifies key distribution and storage.
+Public key management is based on X.509 certificates,
+which can be provided by commercial services or
+produced by utility programs in the OpenSSL software library
+or the NTPv4 distribution.
+.Pp
+While the algorithms for symmetric key cryptography are
+included in the NTPv4 distribution, public key cryptography
+requires the OpenSSL software library to be installed
+before building the NTP distribution.
+Directions for doing that
+are on the Building and Installing the Distribution page.
+.Pp
+Authentication is configured separately for each association
+using the
+.Cm key
+or
+.Cm autokey
+subcommand on the
+.Ic peer ,
+.Ic server ,
+.Ic broadcast
+and
+.Ic manycastclient
+configuration commands as described in
+.Sx Configuration Options
+page.
+The authentication
+options described below specify the locations of the key files,
+if other than default, which symmetric keys are trusted
+and the interval between various operations, if other than default.
+.Pp
+Authentication is always enabled,
+although ineffective if not configured as
+described below.
+If a NTP packet arrives
+including a message authentication
+code (MAC), it is accepted only if it
+passes all cryptographic checks.
+The
+checks require correct key ID, key value
+and message digest.
+If the packet has
+been modified in any way or replayed
+by an intruder, it will fail one or more
+of these checks and be discarded.
+Furthermore, the Autokey scheme requires a
+preliminary protocol exchange to obtain
+the server certificate, verify its
+credentials and initialize the protocol
+.Pp
+The
+.Cm auth
+flag controls whether new associations or
+remote configuration commands require cryptographic authentication.
+This flag can be set or reset by the
+.Ic enable
+and
+.Ic disable
+commands and also by remote
+configuration commands sent by a
+.Xr ntpdc 1ntpdcmdoc
+program running in
+another machine.
+If this flag is enabled, which is the default
+case, new broadcast client and symmetric passive associations and
+remote configuration commands must be cryptographically
+authenticated using either symmetric key or public key cryptography.
+If this
+flag is disabled, these operations are effective
+even if not cryptographic
+authenticated.
+It should be understood
+that operating with the
+.Ic auth
+flag disabled invites a significant vulnerability
+where a rogue hacker can
+masquerade as a falseticker and seriously
+disrupt system timekeeping.
+It is
+important to note that this flag has no purpose
+other than to allow or disallow
+a new association in response to new broadcast
+and symmetric active messages
+and remote configuration commands and, in particular,
+the flag has no effect on
+the authentication process itself.
+.Pp
+An attractive alternative where multicast support is available
+is manycast mode, in which clients periodically troll
+for servers as described in the
+.Sx Automatic NTP Configuration Options
+page.
+Either symmetric key or public key
+cryptographic authentication can be used in this mode.
+The principle advantage
+of manycast mode is that potential servers need not be
+configured in advance,
+since the client finds them during regular operation,
+and the configuration
+files for all clients can be identical.
+.Pp
+The security model and protocol schemes for
+both symmetric key and public key
+cryptography are summarized below;
+further details are in the briefings, papers
+and reports at the NTP project page linked from
+.Li http://www.ntp.org/ .
+.Ss Symmetric-Key Cryptography
+The original RFC-1305 specification allows any one of possibly
+65,534 keys, each distinguished by a 32-bit key identifier, to
+authenticate an association.
+The servers and clients involved must
+agree on the key and key identifier to
+authenticate NTP packets.
+Keys and
+related information are specified in a key
+file, usually called
+.Pa ntp.keys ,
+which must be distributed and stored using
+secure means beyond the scope of the NTP protocol itself.
+Besides the keys used
+for ordinary NTP associations,
+additional keys can be used as passwords for the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+utility programs.
+.Pp
+When
+.Xr ntpd 1ntpdmdoc
+is first started, it reads the key file specified in the
+.Ic keys
+configuration command and installs the keys
+in the key cache.
+However,
+individual keys must be activated with the
+.Ic trusted
+command before use.
+This
+allows, for instance, the installation of possibly
+several batches of keys and
+then activating or deactivating each batch
+remotely using
+.Xr ntpdc 1ntpdcmdoc .
+This also provides a revocation capability that can be used
+if a key becomes compromised.
+The
+.Ic requestkey
+command selects the key used as the password for the
+.Xr ntpdc 1ntpdcmdoc
+utility, while the
+.Ic controlkey
+command selects the key used as the password for the
+.Xr ntpq 1ntpqmdoc
+utility.
+.Ss Public Key Cryptography
+NTPv4 supports the original NTPv3 symmetric key scheme
+described in RFC-1305 and in addition the Autokey protocol,
+which is based on public key cryptography.
+The Autokey Version 2 protocol described on the Autokey Protocol
+page verifies packet integrity using MD5 message digests
+and verifies the source with digital signatures and any of several
+digest/signature schemes.
+Optional identity schemes described on the Identity Schemes
+page and based on cryptographic challenge/response algorithms
+are also available.
+Using all of these schemes provides strong security against
+replay with or without modification, spoofing, masquerade
+and most forms of clogging attacks.
+.\" .Pp
+.\" The cryptographic means necessary for all Autokey operations
+.\" is provided by the OpenSSL software library.
+.\" This library is available from http://www.openssl.org/
+.\" and can be installed using the procedures outlined
+.\" in the Building and Installing the Distribution page.
+.\" Once installed,
+.\" the configure and build
+.\" process automatically detects the library and links
+.\" the library routines required.
+.Pp
+The Autokey protocol has several modes of operation
+corresponding to the various NTP modes supported.
+Most modes use a special cookie which can be
+computed independently by the client and server,
+but encrypted in transmission.
+All modes use in addition a variant of the S-KEY scheme,
+in which a pseudo-random key list is generated and used
+in reverse order.
+These schemes are described along with an executive summary,
+current status, briefing slides and reading list on the
+.Sx Autonomous Authentication
+page.
+.Pp
+The specific cryptographic environment used by Autokey servers
+and clients is determined by a set of files
+and soft links generated by the
+.Xr ntp-keygen 1ntpkeygenmdoc
+program.
+This includes a required host key file,
+required certificate file and optional sign key file,
+leapsecond file and identity scheme files.
+The
+digest/signature scheme is specified in the X.509 certificate
+along with the matching sign key.
+There are several schemes
+available in the OpenSSL software library, each identified
+by a specific string such as
+.Cm md5WithRSAEncryption ,
+which stands for the MD5 message digest with RSA
+encryption scheme.
+The current NTP distribution supports
+all the schemes in the OpenSSL library, including
+those based on RSA and DSA digital signatures.
+.Pp
+NTP secure groups can be used to define cryptographic compartments
+and security hierarchies.
+It is important that every host
+in the group be able to construct a certificate trail to one
+or more trusted hosts in the same group.
+Each group
+host runs the Autokey protocol to obtain the certificates
+for all hosts along the trail to one or more trusted hosts.
+This requires the configuration file in all hosts to be
+engineered so that, even under anticipated failure conditions,
+the NTP subnet will form such that every group host can find
+a trail to at least one trusted host.
+.Ss Naming and Addressing
+It is important to note that Autokey does not use DNS to
+resolve addresses, since DNS can't be completely trusted
+until the name servers have synchronized clocks.
+The cryptographic name used by Autokey to bind the host identity
+credentials and cryptographic values must be independent
+of interface, network and any other naming convention.
+The name appears in the host certificate in either or both
+the subject and issuer fields, so protection against
+DNS compromise is essential.
+.Pp
+By convention, the name of an Autokey host is the name returned
+by the Unix
+.Xr gethostname 2
+system call or equivalent in other systems.
+By the system design
+model, there are no provisions to allow alternate names or aliases.
+However, this is not to say that DNS aliases, different names
+for each interface, etc., are constrained in any way.
+.Pp
+It is also important to note that Autokey verifies authenticity
+using the host name, network address and public keys,
+all of which are bound together by the protocol specifically
+to deflect masquerade attacks.
+For this reason Autokey
+includes the source and destinatino IP addresses in message digest
+computations and so the same addresses must be available
+at both the server and client.
+For this reason operation
+with network address translation schemes is not possible.
+This reflects the intended robust security model where government
+and corporate NTP servers are operated outside firewall perimeters.
+.Ss Operation
+A specific combination of authentication scheme (none,
+symmetric key, public key) and identity scheme is called
+a cryptotype, although not all combinations are compatible.
+There may be management configurations where the clients,
+servers and peers may not all support the same cryptotypes.
+A secure NTPv4 subnet can be configured in many ways while
+keeping in mind the principles explained above and
+in this section.
+Note however that some cryptotype
+combinations may successfully interoperate with each other,
+but may not represent good security practice.
+.Pp
+The cryptotype of an association is determined at the time
+of mobilization, either at configuration time or some time
+later when a message of appropriate cryptotype arrives.
+When mobilized by a
+.Ic server
+or
+.Ic peer
+configuration command and no
+.Ic key
+or
+.Ic autokey
+subcommands are present, the association is not
+authenticated; if the
+.Ic key
+subcommand is present, the association is authenticated
+using the symmetric key ID specified; if the
+.Ic autokey
+subcommand is present, the association is authenticated
+using Autokey.
+.Pp
+When multiple identity schemes are supported in the Autokey
+protocol, the first message exchange determines which one is used.
+The client request message contains bits corresponding
+to which schemes it has available.
+The server response message
+contains bits corresponding to which schemes it has available.
+Both server and client match the received bits with their own
+and select a common scheme.
+.Pp
+Following the principle that time is a public value,
+a server responds to any client packet that matches
+its cryptotype capabilities.
+Thus, a server receiving
+an unauthenticated packet will respond with an unauthenticated
+packet, while the same server receiving a packet of a cryptotype
+it supports will respond with packets of that cryptotype.
+However, unconfigured broadcast or manycast client
+associations or symmetric passive associations will not be
+mobilized unless the server supports a cryptotype compatible
+with the first packet received.
+By default, unauthenticated associations will not be mobilized
+unless overridden in a decidedly dangerous way.
+.Pp
+Some examples may help to reduce confusion.
+Client Alice has no specific cryptotype selected.
+Server Bob has both a symmetric key file and minimal Autokey files.
+Alice's unauthenticated messages arrive at Bob, who replies with
+unauthenticated messages.
+Cathy has a copy of Bob's symmetric
+key file and has selected key ID 4 in messages to Bob.
+Bob verifies the message with his key ID 4.
+If it's the
+same key and the message is verified, Bob sends Cathy a reply
+authenticated with that key.
+If verification fails,
+Bob sends Cathy a thing called a crypto-NAK, which tells her
+something broke.
+She can see the evidence using the
+.Xr ntpq 1ntpqmdoc
+program.
+.Pp
+Denise has rolled her own host key and certificate.
+She also uses one of the identity schemes as Bob.
+She sends the first Autokey message to Bob and they
+both dance the protocol authentication and identity steps.
+If all comes out okay, Denise and Bob continue as described above.
+.Pp
+It should be clear from the above that Bob can support
+all the girls at the same time, as long as he has compatible
+authentication and identity credentials.
+Now, Bob can act just like the girls in his own choice of servers;
+he can run multiple configured associations with multiple different
+servers (or the same server, although that might not be useful).
+But, wise security policy might preclude some cryptotype
+combinations; for instance, running an identity scheme
+with one server and no authentication with another might not be wise.
+.Ss Key Management
+The cryptographic values used by the Autokey protocol are
+incorporated as a set of files generated by the
+.Xr ntp-keygen 1ntpkeygenmdoc
+utility program, including symmetric key, host key and
+public certificate files, as well as sign key, identity parameters
+and leapseconds files.
+Alternatively, host and sign keys and
+certificate files can be generated by the OpenSSL utilities
+and certificates can be imported from public certificate
+authorities.
+Note that symmetric keys are necessary for the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+utility programs.
+The remaining files are necessary only for the
+Autokey protocol.
+.Pp
+Certificates imported from OpenSSL or public certificate
+authorities have certian limitations.
+The certificate should be in ASN.1 syntax, X.509 Version 3
+format and encoded in PEM, which is the same format
+used by OpenSSL.
+The overall length of the certificate encoded
+in ASN.1 must not exceed 1024 bytes.
+The subject distinguished
+name field (CN) is the fully qualified name of the host
+on which it is used; the remaining subject fields are ignored.
+The certificate extension fields must not contain either
+a subject key identifier or a issuer key identifier field;
+however, an extended key usage field for a trusted host must
+contain the value
+.Cm trustRoot ; .
+Other extension fields are ignored.
+.Ss Authentication Commands
+.Bl -tag -width indent
+.It Ic autokey Op Ar logsec
+Specifies the interval between regenerations of the session key
+list used with the Autokey protocol.
+Note that the size of the key
+list for each association depends on this interval and the current
+poll interval.
+The default value is 12 (4096 s or about 1.1 hours).
+For poll intervals above the specified interval, a session key list
+with a single entry will be regenerated for every message
+sent.
+.It Ic controlkey Ar key
+Specifies the key identifier to use with the
+.Xr ntpq 1ntpqmdoc
+utility, which uses the standard
+protocol defined in RFC-1305.
+The
+.Ar key
+argument is
+the key identifier for a trusted key, where the value can be in the
+range 1 to 65,534, inclusive.
+.It Xo Ic crypto
+.Op Cm cert Ar file
+.Op Cm leap Ar file
+.Op Cm randfile Ar file
+.Op Cm host Ar file
+.Op Cm sign Ar file
+.Op Cm gq Ar file
+.Op Cm gqpar Ar file
+.Op Cm iffpar Ar file
+.Op Cm mvpar Ar file
+.Op Cm pw Ar password
+.Xc
+This command requires the OpenSSL library.
+It activates public key
+cryptography, selects the message digest and signature
+encryption scheme and loads the required private and public
+values described above.
+If one or more files are left unspecified,
+the default names are used as described above.
+Unless the complete path and name of the file are specified, the
+location of a file is relative to the keys directory specified
+in the
+.Ic keysdir
+command or default
+.Pa /usr/local/etc .
+Following are the subcommands:
+.Bl -tag -width indent
+.It Cm cert Ar file
+Specifies the location of the required host public certificate file.
+This overrides the link
+.Pa ntpkey_cert_ Ns Ar hostname
+in the keys directory.
+.It Cm gqpar Ar file
+Specifies the location of the optional GQ parameters file.
+This
+overrides the link
+.Pa ntpkey_gq_ Ns Ar hostname
+in the keys directory.
+.It Cm host Ar file
+Specifies the location of the required host key file.
+This overrides
+the link
+.Pa ntpkey_key_ Ns Ar hostname
+in the keys directory.
+.It Cm iffpar Ar file
+Specifies the location of the optional IFF parameters file.This
+overrides the link
+.Pa ntpkey_iff_ Ns Ar hostname
+in the keys directory.
+.It Cm leap Ar file
+Specifies the location of the optional leapsecond file.
+This overrides the link
+.Pa ntpkey_leap
+in the keys directory.
+.It Cm mvpar Ar file
+Specifies the location of the optional MV parameters file.
+This
+overrides the link
+.Pa ntpkey_mv_ Ns Ar hostname
+in the keys directory.
+.It Cm pw Ar password
+Specifies the password to decrypt files containing private keys and
+identity parameters.
+This is required only if these files have been
+encrypted.
+.It Cm randfile Ar file
+Specifies the location of the random seed file used by the OpenSSL
+library.
+The defaults are described in the main text above.
+.It Cm sign Ar file
+Specifies the location of the optional sign key file.
+This overrides
+the link
+.Pa ntpkey_sign_ Ns Ar hostname
+in the keys directory.
+If this file is
+not found, the host key is also the sign key.
+.El
+.It Ic keys Ar keyfile
+Specifies the complete path and location of the MD5 key file
+containing the keys and key identifiers used by
+.Xr ntpd 1ntpdmdoc ,
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+when operating with symmetric key cryptography.
+This is the same operation as the
+.Fl k
+command line option.
+.It Ic keysdir Ar path
+This command specifies the default directory path for
+cryptographic keys, parameters and certificates.
+The default is
+.Pa /usr/local/etc/ .
+.It Ic requestkey Ar key
+Specifies the key identifier to use with the
+.Xr ntpdc 1ntpdcmdoc
+utility program, which uses a
+proprietary protocol specific to this implementation of
+.Xr ntpd 1ntpdmdoc .
+The
+.Ar key
+argument is a key identifier
+for the trusted key, where the value can be in the range 1 to
+65,534, inclusive.
+.It Ic revoke Ar logsec
+Specifies the interval between re-randomization of certain
+cryptographic values used by the Autokey scheme, as a power of 2 in
+seconds.
+These values need to be updated frequently in order to
+deflect brute-force attacks on the algorithms of the scheme;
+however, updating some values is a relatively expensive operation.
+The default interval is 16 (65,536 s or about 18 hours).
+For poll
+intervals above the specified interval, the values will be updated
+for every message sent.
+.It Ic trustedkey Ar key ...
+Specifies the key identifiers which are trusted for the
+purposes of authenticating peers with symmetric key cryptography,
+as well as keys used by the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+programs.
+The authentication procedures require that both the local
+and remote servers share the same key and key identifier for this
+purpose, although different keys can be used with different
+servers.
+The
+.Ar key
+arguments are 32-bit unsigned
+integers with values from 1 to 65,534.
+.El
+.Ss Error Codes
+The following error codes are reported via the NTP control
+and monitoring protocol trap mechanism.
+.Bl -tag -width indent
+.It 101
+.Pq bad field format or length
+The packet has invalid version, length or format.
+.It 102
+.Pq bad timestamp
+The packet timestamp is the same or older than the most recent received.
+This could be due to a replay or a server clock time step.
+.It 103
+.Pq bad filestamp
+The packet filestamp is the same or older than the most recent received.
+This could be due to a replay or a key file generation error.
+.It 104
+.Pq bad or missing public key
+The public key is missing, has incorrect format or is an unsupported type.
+.It 105
+.Pq unsupported digest type
+The server requires an unsupported digest/signature scheme.
+.It 106
+.Pq mismatched digest types
+Not used.
+.It 107
+.Pq bad signature length
+The signature length does not match the current public key.
+.It 108
+.Pq signature not verified
+The message fails the signature check.
+It could be bogus or signed by a
+different private key.
+.It 109
+.Pq certificate not verified
+The certificate is invalid or signed with the wrong key.
+.It 110
+.Pq certificate not verified
+The certificate is not yet valid or has expired or the signature could not
+be verified.
+.It 111
+.Pq bad or missing cookie
+The cookie is missing, corrupted or bogus.
+.It 112
+.Pq bad or missing leapseconds table
+The leapseconds table is missing, corrupted or bogus.
+.It 113
+.Pq bad or missing certificate
+The certificate is missing, corrupted or bogus.
+.It 114
+.Pq bad or missing identity
+The identity key is missing, corrupt or bogus.
+.El
+.Sh Monitoring Support
+.Xr ntpd 1ntpdmdoc
+includes a comprehensive monitoring facility suitable
+for continuous, long term recording of server and client
+timekeeping performance.
+See the
+.Ic statistics
+command below
+for a listing and example of each type of statistics currently
+supported.
+Statistic files are managed using file generation sets
+and scripts in the
+.Pa ./scripts
+directory of this distribution.
+Using
+these facilities and
+.Ux
+.Xr cron 8
+jobs, the data can be
+automatically summarized and archived for retrospective analysis.
+.Ss Monitoring Commands
+.Bl -tag -width indent
+.It Ic statistics Ar name ...
+Enables writing of statistics records.
+Currently, four kinds of
+.Ar name
+statistics are supported.
+.Bl -tag -width indent
+.It Cm clockstats
+Enables recording of clock driver statistics information.
+Each update
+received from a clock driver appends a line of the following form to
+the file generation set named
+.Cm clockstats :
+.Bd -literal
+49213 525.624 127.127.4.1 93 226 00:08:29.606 D
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The next field shows the
+clock address in dotted-quad notation.
+The final field shows the last
+timecode received from the clock in decoded ASCII format, where
+meaningful.
+In some clock drivers a good deal of additional information
+can be gathered and displayed as well.
+See information specific to each
+clock for further details.
+.It Cm cryptostats
+This option requires the OpenSSL cryptographic software library.
+It
+enables recording of cryptographic public key protocol information.
+Each message received by the protocol module appends a line of the
+following form to the file generation set named
+.Cm cryptostats :
+.Bd -literal
+49213 525.624 127.127.4.1 message
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The next field shows the peer
+address in dotted-quad notation, The final message field includes the
+message type and certain ancillary information.
+See the
+.Sx Authentication Options
+section for further information.
+.It Cm loopstats
+Enables recording of loop filter statistics information.
+Each
+update of the local clock outputs a line of the following form to
+the file generation set named
+.Cm loopstats :
+.Bd -literal
+50935 75440.031 0.000006019 13.778190 0.000351733 0.0133806
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next five fields
+show time offset (seconds), frequency offset (parts per million -
+PPM), RMS jitter (seconds), Allan deviation (PPM) and clock
+discipline time constant.
+.It Cm peerstats
+Enables recording of peer statistics information.
+This includes
+statistics records of all peers of a NTP server and of special
+signals, where present and configured.
+Each valid update appends a
+line of the following form to the current element of a file
+generation set named
+.Cm peerstats :
+.Bd -literal
+48773 10847.650 127.127.4.1 9714 -0.001605376 0.000000000 0.001424877 0.000958674
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next two fields
+show the peer address in dotted-quad notation and status,
+respectively.
+The status field is encoded in hex in the format
+described in Appendix A of the NTP specification RFC 1305.
+The final four fields show the offset,
+delay, dispersion and RMS jitter, all in seconds.
+.It Cm rawstats
+Enables recording of raw-timestamp statistics information.
+This
+includes statistics records of all peers of a NTP server and of
+special signals, where present and configured.
+Each NTP message
+received from a peer or clock driver appends a line of the
+following form to the file generation set named
+.Cm rawstats :
+.Bd -literal
+50928 2132.543 128.4.1.1 128.4.1.20 3102453281.584327000 3102453281.58622800031 02453332.540806000 3102453332.541458000
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next two fields
+show the remote peer or clock address followed by the local address
+in dotted-quad notation.
+The final four fields show the originate,
+receive, transmit and final NTP timestamps in order.
+The timestamp
+values are as received and before processing by the various data
+smoothing and mitigation algorithms.
+.It Cm sysstats
+Enables recording of ntpd statistics counters on a periodic basis.
+Each
+hour a line of the following form is appended to the file generation
+set named
+.Cm sysstats :
+.Bd -literal
+50928 2132.543 36000 81965 0 9546 56 71793 512 540 10 147
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The remaining ten fields show
+the statistics counter values accumulated since the last generated
+line.
+.Bl -tag -width indent
+.It Time since restart Cm 36000
+Time in hours since the system was last rebooted.
+.It Packets received Cm 81965
+Total number of packets received.
+.It Packets processed Cm 0
+Number of packets received in response to previous packets sent
+.It Current version Cm 9546
+Number of packets matching the current NTP version.
+.It Previous version Cm 56
+Number of packets matching the previous NTP version.
+.It Bad version Cm 71793
+Number of packets matching neither NTP version.
+.It Access denied Cm 512
+Number of packets denied access for any reason.
+.It Bad length or format Cm 540
+Number of packets with invalid length, format or port number.
+.It Bad authentication Cm 10
+Number of packets not verified as authentic.
+.It Rate exceeded Cm 147
+Number of packets discarded due to rate limitation.
+.El
+.It Cm statsdir Ar directory_path
+Indicates the full path of a directory where statistics files
+should be created (see below).
+This keyword allows
+the (otherwise constant)
+.Cm filegen
+filename prefix to be modified for file generation sets, which
+is useful for handling statistics logs.
+.It Cm filegen Ar name Xo
+.Op Cm file Ar filename
+.Op Cm type Ar typename
+.Op Cm link | nolink
+.Op Cm enable | disable
+.Xc
+Configures setting of generation file set name.
+Generation
+file sets provide a means for handling files that are
+continuously growing during the lifetime of a server.
+Server statistics are a typical example for such files.
+Generation file sets provide access to a set of files used
+to store the actual data.
+At any time at most one element
+of the set is being written to.
+The type given specifies
+when and how data will be directed to a new element of the set.
+This way, information stored in elements of a file set
+that are currently unused are available for administrational
+operations without the risk of disturbing the operation of ntpd.
+(Most important: they can be removed to free space for new data
+produced.)
+.Pp
+Note that this command can be sent from the
+.Xr ntpdc 1ntpdcmdoc
+program running at a remote location.
+.Bl -tag -width indent
+.It Cm name
+This is the type of the statistics records, as shown in the
+.Cm statistics
+command.
+.It Cm file Ar filename
+This is the file name for the statistics records.
+Filenames of set
+members are built from three concatenated elements
+.Ar Cm prefix ,
+.Ar Cm filename
+and
+.Ar Cm suffix :
+.Bl -tag -width indent
+.It Cm prefix
+This is a constant filename path.
+It is not subject to
+modifications via the
+.Ar filegen
+option.
+It is defined by the
+server, usually specified as a compile-time constant.
+It may,
+however, be configurable for individual file generation sets
+via other commands.
+For example, the prefix used with
+.Ar loopstats
+and
+.Ar peerstats
+generation can be configured using the
+.Ar statsdir
+option explained above.
+.It Cm filename
+This string is directly concatenated to the prefix mentioned
+above (no intervening
+.Ql / ) .
+This can be modified using
+the file argument to the
+.Ar filegen
+statement.
+No
+.Pa ..
+elements are
+allowed in this component to prevent filenames referring to
+parts outside the filesystem hierarchy denoted by
+.Ar prefix .
+.It Cm suffix
+This part is reflects individual elements of a file set.
+It is
+generated according to the type of a file set.
+.El
+.It Cm type Ar typename
+A file generation set is characterized by its type.
+The following
+types are supported:
+.Bl -tag -width indent
+.It Cm none
+The file set is actually a single plain file.
+.It Cm pid
+One element of file set is used per incarnation of a ntpd
+server.
+This type does not perform any changes to file set
+members during runtime, however it provides an easy way of
+separating files belonging to different
+.Xr ntpd 1ntpdmdoc
+server incarnations.
+The set member filename is built by appending a
+.Ql \&.
+to concatenated
+.Ar prefix
+and
+.Ar filename
+strings, and
+appending the decimal representation of the process ID of the
+.Xr ntpd 1ntpdmdoc
+server process.
+.It Cm day
+One file generation set element is created per day.
+A day is
+defined as the period between 00:00 and 24:00 UTC.
+The file set
+member suffix consists of a
+.Ql \&.
+and a day specification in
+the form
+.Cm YYYYMMdd .
+.Cm YYYY
+is a 4-digit year number (e.g., 1992).
+.Cm MM
+is a two digit month number.
+.Cm dd
+is a two digit day number.
+Thus, all information written at 10 December 1992 would end up
+in a file named
+.Ar prefix
+.Ar filename Ns .19921210 .
+.It Cm week
+Any file set member contains data related to a certain week of
+a year.
+The term week is defined by computing day-of-year
+modulo 7.
+Elements of such a file generation set are
+distinguished by appending the following suffix to the file set
+filename base: A dot, a 4-digit year number, the letter
+.Cm W ,
+and a 2-digit week number.
+For example, information from January,
+10th 1992 would end up in a file with suffix
+.No . Ns Ar 1992W1 .
+.It Cm month
+One generation file set element is generated per month.
+The
+file name suffix consists of a dot, a 4-digit year number, and
+a 2-digit month.
+.It Cm year
+One generation file element is generated per year.
+The filename
+suffix consists of a dot and a 4 digit year number.
+.It Cm age
+This type of file generation sets changes to a new element of
+the file set every 24 hours of server operation.
+The filename
+suffix consists of a dot, the letter
+.Cm a ,
+and an 8-digit number.
+This number is taken to be the number of seconds the server is
+running at the start of the corresponding 24-hour period.
+Information is only written to a file generation by specifying
+.Cm enable ;
+output is prevented by specifying
+.Cm disable .
+.El
+.It Cm link | nolink
+It is convenient to be able to access the current element of a file
+generation set by a fixed name.
+This feature is enabled by
+specifying
+.Cm link
+and disabled using
+.Cm nolink .
+If link is specified, a
+hard link from the current file set element to a file without
+suffix is created.
+When there is already a file with this name and
+the number of links of this file is one, it is renamed appending a
+dot, the letter
+.Cm C ,
+and the pid of the ntpd server process.
+When the
+number of links is greater than one, the file is unlinked.
+This
+allows the current file to be accessed by a constant name.
+.It Cm enable \&| Cm disable
+Enables or disables the recording function.
+.El
+.El
+.El
+.Sh Access Control Support
+The
+.Xr ntpd 1ntpdmdoc
+daemon implements a general purpose address/mask based restriction
+list.
+The list contains address/match entries sorted first
+by increasing address values and and then by increasing mask values.
+A match occurs when the bitwise AND of the mask and the packet
+source address is equal to the bitwise AND of the mask and
+address in the list.
+The list is searched in order with the
+last match found defining the restriction flags associated
+with the entry.
+Additional information and examples can be found in the
+.Qq Notes on Configuring NTP and Setting up a NTP Subnet
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.Pp
+The restriction facility was implemented in conformance
+with the access policies for the original NSFnet backbone
+time servers.
+Later the facility was expanded to deflect
+cryptographic and clogging attacks.
+While this facility may
+be useful for keeping unwanted or broken or malicious clients
+from congesting innocent servers, it should not be considered
+an alternative to the NTP authentication facilities.
+Source address based restrictions are easily circumvented
+by a determined cracker.
+.Pp
+Clients can be denied service because they are explicitly
+included in the restrict list created by the restrict command
+or implicitly as the result of cryptographic or rate limit
+violations.
+Cryptographic violations include certificate
+or identity verification failure; rate limit violations generally
+result from defective NTP implementations that send packets
+at abusive rates.
+Some violations cause denied service
+only for the offending packet, others cause denied service
+for a timed period and others cause the denied service for
+an indefinate period.
+When a client or network is denied access
+for an indefinate period, the only way at present to remove
+the restrictions is by restarting the server.
+.Ss The Kiss-of-Death Packet
+Ordinarily, packets denied service are simply dropped with no
+further action except incrementing statistics counters.
+Sometimes a
+more proactive response is needed, such as a server message that
+explicitly requests the client to stop sending and leave a message
+for the system operator.
+A special packet format has been created
+for this purpose called the "kiss-of-death" (KoD) packet.
+KoD packets have the leap bits set unsynchronized and stratum set
+to zero and the reference identifier field set to a four-byte
+ASCII code.
+If the
+.Cm noserve
+or
+.Cm notrust
+flag of the matching restrict list entry is set,
+the code is "DENY"; if the
+.Cm limited
+flag is set and the rate limit
+is exceeded, the code is "RATE".
+Finally, if a cryptographic violation occurs, the code is "CRYP".
+.Pp
+A client receiving a KoD performs a set of sanity checks to
+minimize security exposure, then updates the stratum and
+reference identifier peer variables, sets the access
+denied (TEST4) bit in the peer flash variable and sends
+a message to the log.
+As long as the TEST4 bit is set,
+the client will send no further packets to the server.
+The only way at present to recover from this condition is
+to restart the protocol at both the client and server.
+This
+happens automatically at the client when the association times out.
+It will happen at the server only if the server operator cooperates.
+.Ss Access Control Commands
+.Bl -tag -width indent
+.It Xo Ic discard
+.Op Cm average Ar avg
+.Op Cm minimum Ar min
+.Op Cm monitor Ar prob
+.Xc
+Set the parameters of the
+.Cm limited
+facility which protects the server from
+client abuse.
+The
+.Cm average
+subcommand specifies the minimum average packet
+spacing, while the
+.Cm minimum
+subcommand specifies the minimum packet spacing.
+Packets that violate these minima are discarded
+and a kiss-o'-death packet returned if enabled.
+The default
+minimum average and minimum are 5 and 2, respectively.
+The monitor subcommand specifies the probability of discard
+for packets that overflow the rate-control window.
+.It Xo Ic restrict address
+.Op Cm mask Ar mask
+.Op Ar flag ...
+.Xc
+The
+.Ar address
+argument expressed in
+dotted-quad form is the address of a host or network.
+Alternatively, the
+.Ar address
+argument can be a valid host DNS name.
+The
+.Ar mask
+argument expressed in dotted-quad form defaults to
+.Cm 255.255.255.255 ,
+meaning that the
+.Ar address
+is treated as the address of an individual host.
+A default entry (address
+.Cm 0.0.0.0 ,
+mask
+.Cm 0.0.0.0 )
+is always included and is always the first entry in the list.
+Note that text string
+.Cm default ,
+with no mask option, may
+be used to indicate the default entry.
+In the current implementation,
+.Cm flag
+always
+restricts access, i.e., an entry with no flags indicates that free
+access to the server is to be given.
+The flags are not orthogonal,
+in that more restrictive flags will often make less restrictive
+ones redundant.
+The flags can generally be classed into two
+categories, those which restrict time service and those which
+restrict informational queries and attempts to do run-time
+reconfiguration of the server.
+One or more of the following flags
+may be specified:
+.Bl -tag -width indent
+.It Cm ignore
+Deny packets of all kinds, including
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+queries.
+.It Cm kod
+If this flag is set when an access violation occurs, a kiss-o'-death
+(KoD) packet is sent.
+KoD packets are rate limited to no more than one
+per second.
+If another KoD packet occurs within one second after the
+last one, the packet is dropped.
+.It Cm limited
+Deny service if the packet spacing violates the lower limits specified
+in the discard command.
+A history of clients is kept using the
+monitoring capability of
+.Xr ntpd 1ntpdmdoc .
+Thus, monitoring is always active as
+long as there is a restriction entry with the
+.Cm limited
+flag.
+.It Cm lowpriotrap
+Declare traps set by matching hosts to be low priority.
+The
+number of traps a server can maintain is limited (the current limit
+is 3).
+Traps are usually assigned on a first come, first served
+basis, with later trap requestors being denied service.
+This flag
+modifies the assignment algorithm by allowing low priority traps to
+be overridden by later requests for normal priority traps.
+.It Cm nomodify
+Deny
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+queries which attempt to modify the state of the
+server (i.e., run time reconfiguration).
+Queries which return
+information are permitted.
+.It Cm noquery
+Deny
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+queries.
+Time service is not affected.
+.It Cm nopeer
+Deny packets which would result in mobilizing a new association.
+This
+includes broadcast and symmetric active packets when a configured
+association does not exist.
+.It Cm noserve
+Deny all packets except
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+queries.
+.It Cm notrap
+Decline to provide mode 6 control message trap service to matching
+hosts.
+The trap service is a subsystem of the ntpdq control message
+protocol which is intended for use by remote event logging programs.
+.It Cm notrust
+Deny service unless the packet is cryptographically authenticated.
+.It Cm ntpport
+This is actually a match algorithm modifier, rather than a
+restriction flag.
+Its presence causes the restriction entry to be
+matched only if the source port in the packet is the standard NTP
+UDP port (123).
+Both
+.Cm ntpport
+and
+.Cm non-ntpport
+may
+be specified.
+The
+.Cm ntpport
+is considered more specific and
+is sorted later in the list.
+.It Cm version
+Deny packets that do not match the current NTP version.
+.El
+.Pp
+Default restriction list entries with the flags ignore, interface,
+ntpport, for each of the local host's interface addresses are
+inserted into the table at startup to prevent the server
+from attempting to synchronize to its own time.
+A default entry is also always present, though if it is
+otherwise unconfigured; no flags are associated
+with the default entry (i.e., everything besides your own
+NTP server is unrestricted).
+.El
+.Sh Automatic NTP Configuration Options
+.Ss Manycasting
+Manycasting is a automatic discovery and configuration paradigm
+new to NTPv4.
+It is intended as a means for a multicast client
+to troll the nearby network neighborhood to find cooperating
+manycast servers, validate them using cryptographic means
+and evaluate their time values with respect to other servers
+that might be lurking in the vicinity.
+The intended result is that each manycast client mobilizes
+client associations with some number of the "best"
+of the nearby manycast servers, yet automatically reconfigures
+to sustain this number of servers should one or another fail.
+.Pp
+Note that the manycasting paradigm does not coincide
+with the anycast paradigm described in RFC-1546,
+which is designed to find a single server from a clique
+of servers providing the same service.
+The manycast paradigm is designed to find a plurality
+of redundant servers satisfying defined optimality criteria.
+.Pp
+Manycasting can be used with either symmetric key
+or public key cryptography.
+The public key infrastructure (PKI)
+offers the best protection against compromised keys
+and is generally considered stronger, at least with relatively
+large key sizes.
+It is implemented using the Autokey protocol and
+the OpenSSL cryptographic library available from
+.Li http://www.openssl.org/ .
+The library can also be used with other NTPv4 modes
+as well and is highly recommended, especially for broadcast modes.
+.Pp
+A persistent manycast client association is configured
+using the manycastclient command, which is similar to the
+server command but with a multicast (IPv4 class
+.Cm D
+or IPv6 prefix
+.Cm FF )
+group address.
+The IANA has designated IPv4 address 224.1.1.1
+and IPv6 address FF05::101 (site local) for NTP.
+When more servers are needed, it broadcasts manycast
+client messages to this address at the minimum feasible rate
+and minimum feasible time-to-live (TTL) hops, depending
+on how many servers have already been found.
+There can be as many manycast client associations
+as different group address, each one serving as a template
+for a future ephemeral unicast client/server association.
+.Pp
+Manycast servers configured with the
+.Ic manycastserver
+command listen on the specified group address for manycast
+client messages.
+Note the distinction between manycast client,
+which actively broadcasts messages, and manycast server,
+which passively responds to them.
+If a manycast server is
+in scope of the current TTL and is itself synchronized
+to a valid source and operating at a stratum level equal
+to or lower than the manycast client, it replies to the
+manycast client message with an ordinary unicast server message.
+.Pp
+The manycast client receiving this message mobilizes
+an ephemeral client/server association according to the
+matching manycast client template, but only if cryptographically
+authenticated and the server stratum is less than or equal
+to the client stratum.
+Authentication is explicitly required
+and either symmetric key or public key (Autokey) can be used.
+Then, the client polls the server at its unicast address
+in burst mode in order to reliably set the host clock
+and validate the source.
+This normally results
+in a volley of eight client/server at 2-s intervals
+during which both the synchronization and cryptographic
+protocols run concurrently.
+Following the volley,
+the client runs the NTP intersection and clustering
+algorithms, which act to discard all but the "best"
+associations according to stratum and synchronization
+distance.
+The surviving associations then continue
+in ordinary client/server mode.
+.Pp
+The manycast client polling strategy is designed to reduce
+as much as possible the volume of manycast client messages
+and the effects of implosion due to near-simultaneous
+arrival of manycast server messages.
+The strategy is determined by the
+.Ic manycastclient ,
+.Ic tos
+and
+.Ic ttl
+configuration commands.
+The manycast poll interval is
+normally eight times the system poll interval,
+which starts out at the
+.Cm minpoll
+value specified in the
+.Ic manycastclient ,
+command and, under normal circumstances, increments to the
+.Cm maxpolll
+value specified in this command.
+Initially, the TTL is
+set at the minimum hops specified by the ttl command.
+At each retransmission the TTL is increased until reaching
+the maximum hops specified by this command or a sufficient
+number client associations have been found.
+Further retransmissions use the same TTL.
+.Pp
+The quality and reliability of the suite of associations
+discovered by the manycast client is determined by the NTP
+mitigation algorithms and the
+.Cm minclock
+and
+.Cm minsane
+values specified in the
+.Ic tos
+configuration command.
+At least
+.Cm minsane
+candidate servers must be available and the mitigation
+algorithms produce at least
+.Cm minclock
+survivors in order to synchronize the clock.
+Byzantine agreement principles require at least four
+candidates in order to correctly discard a single falseticker.
+For legacy purposes,
+.Cm minsane
+defaults to 1 and
+.Cm minclock
+defaults to 3.
+For manycast service
+.Cm minsane
+should be explicitly set to 4, assuming at least that
+number of servers are available.
+.Pp
+If at least
+.Cm minclock
+servers are found, the manycast poll interval is immediately
+set to eight times
+.Cm maxpoll .
+If less than
+.Cm minclock
+servers are found when the TTL has reached the maximum hops,
+the manycast poll interval is doubled.
+For each transmission
+after that, the poll interval is doubled again until
+reaching the maximum of eight times
+.Cm maxpoll .
+Further transmissions use the same poll interval and
+TTL values.
+Note that while all this is going on,
+each client/server association found is operating normally
+it the system poll interval.
+.Pp
+Administratively scoped multicast boundaries are normally
+specified by the network router configuration and,
+in the case of IPv6, the link/site scope prefix.
+By default, the increment for TTL hops is 32 starting
+from 31; however, the
+.Ic ttl
+configuration command can be
+used to modify the values to match the scope rules.
+.Pp
+It is often useful to narrow the range of acceptable
+servers which can be found by manycast client associations.
+Because manycast servers respond only when the client
+stratum is equal to or greater than the server stratum,
+primary (stratum 1) servers fill find only primary servers
+in TTL range, which is probably the most common objective.
+However, unless configured otherwise, all manycast clients
+in TTL range will eventually find all primary servers
+in TTL range, which is probably not the most common
+objective in large networks.
+The
+.Ic tos
+command can be used to modify this behavior.
+Servers with stratum below
+.Cm floor
+or above
+.Cm ceiling
+specified in the
+.Ic tos
+command are strongly discouraged during the selection
+process; however, these servers may be temporally
+accepted if the number of servers within TTL range is
+less than
+.Cm minclock .
+.Pp
+The above actions occur for each manycast client message,
+which repeats at the designated poll interval.
+However, once the ephemeral client association is mobilized,
+subsequent manycast server replies are discarded,
+since that would result in a duplicate association.
+If during a poll interval the number of client associations
+falls below
+.Cm minclock ,
+all manycast client prototype associations are reset
+to the initial poll interval and TTL hops and operation
+resumes from the beginning.
+It is important to avoid
+frequent manycast client messages, since each one requires
+all manycast servers in TTL range to respond.
+The result could well be an implosion, either minor or major,
+depending on the number of servers in range.
+The recommended value for
+.Cm maxpoll
+is 12 (4,096 s).
+.Pp
+It is possible and frequently useful to configure a host
+as both manycast client and manycast server.
+A number of hosts configured this way and sharing a common
+group address will automatically organize themselves
+in an optimum configuration based on stratum and
+synchronization distance.
+For example, consider an NTP
+subnet of two primary servers and a hundred or more
+dependent clients.
+With two exceptions, all servers
+and clients have identical configuration files including both
+.Ic multicastclient
+and
+.Ic multicastserver
+commands using, for instance, multicast group address
+239.1.1.1.
+The only exception is that each primary server
+configuration file must include commands for the primary
+reference source such as a GPS receiver.
+.Pp
+The remaining configuration files for all secondary
+servers and clients have the same contents, except for the
+.Ic tos
+command, which is specific for each stratum level.
+For stratum 1 and stratum 2 servers, that command is
+not necessary.
+For stratum 3 and above servers the
+.Cm floor
+value is set to the intended stratum number.
+Thus, all stratum 3 configuration files are identical,
+all stratum 4 files are identical and so forth.
+.Pp
+Once operations have stabilized in this scenario,
+the primary servers will find the primary reference source
+and each other, since they both operate at the same
+stratum (1), but not with any secondary server or client,
+since these operate at a higher stratum.
+The secondary
+servers will find the servers at the same stratum level.
+If one of the primary servers loses its GPS receiver,
+it will continue to operate as a client and other clients
+will time out the corresponding association and
+re-associate accordingly.
+.Pp
+Some administrators prefer to avoid running
+.Xr ntpd 1ntpdmdoc
+continuously and run either
+.Xr ntpdate 8
+or
+.Xr ntpd 1ntpdmdoc
+.Fl q
+as a cron job.
+In either case the servers must be
+configured in advance and the program fails if none are
+available when the cron job runs.
+A really slick
+application of manycast is with
+.Xr ntpd 1ntpdmdoc
+.Fl q .
+The program wakes up, scans the local landscape looking
+for the usual suspects, selects the best from among
+the rascals, sets the clock and then departs.
+Servers do not have to be configured in advance and
+all clients throughout the network can have the same
+configuration file.
+.Ss Manycast Interactions with Autokey
+Each time a manycast client sends a client mode packet
+to a multicast group address, all manycast servers
+in scope generate a reply including the host name
+and status word.
+The manycast clients then run
+the Autokey protocol, which collects and verifies
+all certificates involved.
+Following the burst interval
+all but three survivors are cast off,
+but the certificates remain in the local cache.
+It often happens that several complete signing trails
+from the client to the primary servers are collected in this way.
+.Pp
+About once an hour or less often if the poll interval
+exceeds this, the client regenerates the Autokey key list.
+This is in general transparent in client/server mode.
+However, about once per day the server private value
+used to generate cookies is refreshed along with all
+manycast client associations.
+In this case all
+cryptographic values including certificates is refreshed.
+If a new certificate has been generated since
+the last refresh epoch, it will automatically revoke
+all prior certificates that happen to be in the
+certificate cache.
+At the same time, the manycast
+scheme starts all over from the beginning and
+the expanding ring shrinks to the minimum and increments
+from there while collecting all servers in scope.
+.Ss Manycast Options
+.Bl -tag -width indent
+.It Xo Ic tos
+.Oo
+.Cm ceiling Ar ceiling |
+.Cm cohort { 0 | 1 } |
+.Cm floor Ar floor |
+.Cm minclock Ar minclock |
+.Cm minsane Ar minsane
+.Oc
+.Xc
+This command affects the clock selection and clustering
+algorithms.
+It can be used to select the quality and
+quantity of peers used to synchronize the system clock
+and is most useful in manycast mode.
+The variables operate
+as follows:
+.Bl -tag -width indent
+.It Cm ceiling Ar ceiling
+Peers with strata above
+.Cm ceiling
+will be discarded if there are at least
+.Cm minclock
+peers remaining.
+This value defaults to 15, but can be changed
+to any number from 1 to 15.
+.It Cm cohort Bro 0 | 1 Brc
+This is a binary flag which enables (0) or disables (1)
+manycast server replies to manycast clients with the same
+stratum level.
+This is useful to reduce implosions where
+large numbers of clients with the same stratum level
+are present.
+The default is to enable these replies.
+.It Cm floor Ar floor
+Peers with strata below
+.Cm floor
+will be discarded if there are at least
+.Cm minclock
+peers remaining.
+This value defaults to 1, but can be changed
+to any number from 1 to 15.
+.It Cm minclock Ar minclock
+The clustering algorithm repeatedly casts out outlyer
+associations until no more than
+.Cm minclock
+associations remain.
+This value defaults to 3,
+but can be changed to any number from 1 to the number of
+configured sources.
+.It Cm minsane Ar minsane
+This is the minimum number of candidates available
+to the clock selection algorithm in order to produce
+one or more truechimers for the clustering algorithm.
+If fewer than this number are available, the clock is
+undisciplined and allowed to run free.
+The default is 1
+for legacy purposes.
+However, according to principles of
+Byzantine agreement,
+.Cm minsane
+should be at least 4 in order to detect and discard
+a single falseticker.
+.El
+.It Cm ttl Ar hop ...
+This command specifies a list of TTL values in increasing
+order, up to 8 values can be specified.
+In manycast mode these values are used in turn
+in an expanding-ring search.
+The default is eight
+multiples of 32 starting at 31.
+.El
+.Sh Reference Clock Support
+The NTP Version 4 daemon supports some three dozen different radio,
+satellite and modem reference clocks plus a special pseudo-clock
+used for backup or when no other clock source is available.
+Detailed descriptions of individual device drivers and options can
+be found in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+Additional information can be found in the pages linked
+there, including the
+.Qq Debugging Hints for Reference Clock Drivers
+and
+.Qq How To Write a Reference Clock Driver
+pages
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+In addition, support for a PPS
+signal is available as described in the
+.Qq Pulse-per-second (PPS) Signal Interfacing
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+Many
+drivers support special line discipline/streams modules which can
+significantly improve the accuracy using the driver.
+These are
+described in the
+.Qq Line Disciplines and Streams Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.Pp
+A reference clock will generally (though not always) be a radio
+timecode receiver which is synchronized to a source of standard
+time such as the services offered by the NRC in Canada and NIST and
+USNO in the US.
+The interface between the computer and the timecode
+receiver is device dependent, but is usually a serial port.
+A
+device driver specific to each reference clock must be selected and
+compiled in the distribution; however, most common radio, satellite
+and modem clocks are included by default.
+Note that an attempt to
+configure a reference clock when the driver has not been compiled
+or the hardware port has not been appropriately configured results
+in a scalding remark to the system log file, but is otherwise non
+hazardous.
+.Pp
+For the purposes of configuration,
+.Xr ntpd 1ntpdmdoc
+treats
+reference clocks in a manner analogous to normal NTP peers as much
+as possible.
+Reference clocks are identified by a syntactically
+correct but invalid IP address, in order to distinguish them from
+normal NTP peers.
+Reference clock addresses are of the form
+.Sm off
+.Li 127.127. Ar t . Ar u ,
+.Sm on
+where
+.Ar t
+is an integer
+denoting the clock type and
+.Ar u
+indicates the unit
+number in the range 0-3.
+While it may seem overkill, it is in fact
+sometimes useful to configure multiple reference clocks of the same
+type, in which case the unit numbers must be unique.
+.Pp
+The
+.Ic server
+command is used to configure a reference
+clock, where the
+.Ar address
+argument in that command
+is the clock address.
+The
+.Cm key ,
+.Cm version
+and
+.Cm ttl
+options are not used for reference clock support.
+The
+.Cm mode
+option is added for reference clock support, as
+described below.
+The
+.Cm prefer
+option can be useful to
+persuade the server to cherish a reference clock with somewhat more
+enthusiasm than other reference clocks or peers.
+Further
+information on this option can be found in the
+.Qq Mitigation Rules and the prefer Keyword
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page.
+The
+.Cm minpoll
+and
+.Cm maxpoll
+options have
+meaning only for selected clock drivers.
+See the individual clock
+driver document pages for additional information.
+.Pp
+The
+.Ic fudge
+command is used to provide additional
+information for individual clock drivers and normally follows
+immediately after the
+.Ic server
+command.
+The
+.Ar address
+argument specifies the clock address.
+The
+.Cm refid
+and
+.Cm stratum
+options can be used to
+override the defaults for the device.
+There are two optional
+device-dependent time offsets and four flags that can be included
+in the
+.Ic fudge
+command as well.
+.Pp
+The stratum number of a reference clock is by default zero.
+Since the
+.Xr ntpd 1ntpdmdoc
+daemon adds one to the stratum of each
+peer, a primary server ordinarily displays an external stratum of
+one.
+In order to provide engineered backups, it is often useful to
+specify the reference clock stratum as greater than zero.
+The
+.Cm stratum
+option is used for this purpose.
+Also, in cases
+involving both a reference clock and a pulse-per-second (PPS)
+discipline signal, it is useful to specify the reference clock
+identifier as other than the default, depending on the driver.
+The
+.Cm refid
+option is used for this purpose.
+Except where noted,
+these options apply to all clock drivers.
+.Ss Reference Clock Commands
+.Bl -tag -width indent
+.It Xo Ic server
+.Sm off
+.Li 127.127. Ar t . Ar u
+.Sm on
+.Op Cm prefer
+.Op Cm mode Ar int
+.Op Cm minpoll Ar int
+.Op Cm maxpoll Ar int
+.Xc
+This command can be used to configure reference clocks in
+special ways.
+The options are interpreted as follows:
+.Bl -tag -width indent
+.It Cm prefer
+Marks the reference clock as preferred.
+All other things being
+equal, this host will be chosen for synchronization among a set of
+correctly operating hosts.
+See the
+.Qq Mitigation Rules and the prefer Keyword
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+for further information.
+.It Cm mode Ar int
+Specifies a mode number which is interpreted in a
+device-specific fashion.
+For instance, it selects a dialing
+protocol in the ACTS driver and a device subtype in the
+parse
+drivers.
+.It Cm minpoll Ar int
+.It Cm maxpoll Ar int
+These options specify the minimum and maximum polling interval
+for reference clock messages, as a power of 2 in seconds
+For
+most directly connected reference clocks, both
+.Cm minpoll
+and
+.Cm maxpoll
+default to 6 (64 s).
+For modem reference clocks,
+.Cm minpoll
+defaults to 10 (17.1 m) and
+.Cm maxpoll
+defaults to 14 (4.5 h).
+The allowable range is 4 (16 s) to 17 (36.4 h) inclusive.
+.El
+.It Xo Ic fudge
+.Sm off
+.Li 127.127. Ar t . Ar u
+.Sm on
+.Op Cm time1 Ar sec
+.Op Cm time2 Ar sec
+.Op Cm stratum Ar int
+.Op Cm refid Ar string
+.Op Cm mode Ar int
+.Op Cm flag1 Cm 0 \&| Cm 1
+.Op Cm flag2 Cm 0 \&| Cm 1
+.Op Cm flag3 Cm 0 \&| Cm 1
+.Op Cm flag4 Cm 0 \&| Cm 1
+.Xc
+This command can be used to configure reference clocks in
+special ways.
+It must immediately follow the
+.Ic server
+command which configures the driver.
+Note that the same capability
+is possible at run time using the
+.Xr ntpdc 1ntpdcmdoc
+program.
+The options are interpreted as
+follows:
+.Bl -tag -width indent
+.It Cm time1 Ar sec
+Specifies a constant to be added to the time offset produced by
+the driver, a fixed-point decimal number in seconds.
+This is used
+as a calibration constant to adjust the nominal time offset of a
+particular clock to agree with an external standard, such as a
+precision PPS signal.
+It also provides a way to correct a
+systematic error or bias due to serial port or operating system
+latencies, different cable lengths or receiver internal delay.
+The
+specified offset is in addition to the propagation delay provided
+by other means, such as internal DIPswitches.
+Where a calibration
+for an individual system and driver is available, an approximate
+correction is noted in the driver documentation pages.
+Note: in order to facilitate calibration when more than one
+radio clock or PPS signal is supported, a special calibration
+feature is available.
+It takes the form of an argument to the
+.Ic enable
+command described in
+.Sx Miscellaneous Options
+page and operates as described in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.It Cm time2 Ar secs
+Specifies a fixed-point decimal number in seconds, which is
+interpreted in a driver-dependent way.
+See the descriptions of
+specific drivers in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.It Cm stratum Ar int
+Specifies the stratum number assigned to the driver, an integer
+between 0 and 15.
+This number overrides the default stratum number
+ordinarily assigned by the driver itself, usually zero.
+.It Cm refid Ar string
+Specifies an ASCII string of from one to four characters which
+defines the reference identifier used by the driver.
+This string
+overrides the default identifier ordinarily assigned by the driver
+itself.
+.It Cm mode Ar int
+Specifies a mode number which is interpreted in a
+device-specific fashion.
+For instance, it selects a dialing
+protocol in the ACTS driver and a device subtype in the
+parse
+drivers.
+.It Cm flag1 Cm 0 \&| Cm 1
+.It Cm flag2 Cm 0 \&| Cm 1
+.It Cm flag3 Cm 0 \&| Cm 1
+.It Cm flag4 Cm 0 \&| Cm 1
+These four flags are used for customizing the clock driver.
+The
+interpretation of these values, and whether they are used at all,
+is a function of the particular clock driver.
+However, by
+convention
+.Cm flag4
+is used to enable recording monitoring
+data to the
+.Cm clockstats
+file configured with the
+.Ic filegen
+command.
+Further information on the
+.Ic filegen
+command can be found in
+.Sx Monitoring Options .
+.El
+.El
+.Sh Miscellaneous Options
+.Bl -tag -width indent
+.It Ic broadcastdelay Ar seconds
+The broadcast and multicast modes require a special calibration
+to determine the network delay between the local and remote
+servers.
+Ordinarily, this is done automatically by the initial
+protocol exchanges between the client and server.
+In some cases,
+the calibration procedure may fail due to network or server access
+controls, for example.
+This command specifies the default delay to
+be used under these circumstances.
+Typically (for Ethernet), a
+number between 0.003 and 0.007 seconds is appropriate.
+The default
+when this command is not used is 0.004 seconds.
+.It Ic calldelay Ar delay
+This option controls the delay in seconds between the first and second
+packets sent in burst or iburst mode to allow additional time for a modem
+or ISDN call to complete.
+.It Ic driftfile Ar driftfile
+This command specifies the complete path and name of the file used to
+record the frequency of the local clock oscillator.
+This is the same
+operation as the
+.Fl f
+command line option.
+If the file exists, it is read at
+startup in order to set the initial frequency and then updated once per
+hour with the current frequency computed by the daemon.
+If the file name is
+specified, but the file itself does not exist, the starts with an initial
+frequency of zero and creates the file when writing it for the first time.
+If this command is not given, the daemon will always start with an initial
+frequency of zero.
+.Pp
+The file format consists of a single line containing a single
+floating point number, which records the frequency offset measured
+in parts-per-million (PPM).
+The file is updated by first writing
+the current drift value into a temporary file and then renaming
+this file to replace the old version.
+This implies that
+.Xr ntpd 1ntpdmdoc
+must have write permission for the directory the
+drift file is located in, and that file system links, symbolic or
+otherwise, should be avoided.
+.It Xo Ic enable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+.It Xo Ic disable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+Provides a way to enable or disable various server options.
+Flags not mentioned are unaffected.
+Note that all of these flags
+can be controlled remotely using the
+.Xr ntpdc 1ntpdcmdoc
+utility program.
+.Bl -tag -width indent
+.It Cm auth
+Enables the server to synchronize with unconfigured peers only if the
+peer has been correctly authenticated using either public key or
+private key cryptography.
+The default for this flag is
+.Ic enable .
+.It Cm bclient
+Enables the server to listen for a message from a broadcast or
+multicast server, as in the
+.Ic multicastclient
+command with default
+address.
+The default for this flag is
+.Ic disable .
+.It Cm calibrate
+Enables the calibrate feature for reference clocks.
+The default for
+this flag is
+.Ic disable .
+.It Cm kernel
+Enables the kernel time discipline, if available.
+The default for this
+flag is
+.Ic enable
+if support is available, otherwise
+.Ic disable .
+.It Cm monitor
+Enables the monitoring facility.
+See the
+.Xr ntpdc 1ntpdcmdoc
+program
+and the
+.Ic monlist
+command or further information.
+The
+default for this flag is
+.Ic enable .
+.It Cm ntp
+Enables time and frequency discipline.
+In effect, this switch opens and
+closes the feedback loop, which is useful for testing.
+The default for
+this flag is
+.Ic enable .
+.It Cm pps
+Enables the pulse-per-second (PPS) signal when frequency and time is
+disciplined by the precision time kernel modifications.
+See the
+.Qq A Kernel Model for Precision Timekeeping
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page for further information.
+The default for this flag is
+.Ic disable .
+.It Cm stats
+Enables the statistics facility.
+See the
+.Sx Monitoring Options
+section for further information.
+The default for this flag is
+.Ic disable .
+.El
+.It Ic includefile Ar includefile
+This command allows additional configuration commands
+to be included from a separate file.
+Include files may
+be nested to a depth of five; upon reaching the end of any
+include file, command processing resumes in the previous
+configuration file.
+This option is useful for sites that run
+.Xr ntpd 1ntpdmdoc
+on multiple hosts, with (mostly) common options (e.g., a
+restriction list).
+.It Ic logconfig Ar configkeyword
+This command controls the amount and type of output written to
+the system
+.Xr syslog 3
+facility or the alternate
+.Ic logfile
+log file.
+By default, all output is turned on.
+All
+.Ar configkeyword
+keywords can be prefixed with
+.Ql = ,
+.Ql +
+and
+.Ql - ,
+where
+.Ql =
+sets the
+.Xr syslog 3
+priority mask,
+.Ql +
+adds and
+.Ql -
+removes
+messages.
+.Xr syslog 3
+messages can be controlled in four
+classes
+.Po
+.Cm clock ,
+.Cm peer ,
+.Cm sys
+and
+.Cm sync
+.Pc .
+Within these classes four types of messages can be
+controlled: informational messages
+.Po
+.Cm info
+.Pc ,
+event messages
+.Po
+.Cm events
+.Pc ,
+statistics messages
+.Po
+.Cm statistics
+.Pc
+and
+status messages
+.Po
+.Cm status
+.Pc .
+.Pp
+Configuration keywords are formed by concatenating the message class with
+the event class.
+The
+.Cm all
+prefix can be used instead of a message class.
+A
+message class may also be followed by the
+.Cm all
+keyword to enable/disable all
+messages of the respective message class.Thus, a minimal log configuration
+could look like this:
+.Bd -literal
+logconfig =syncstatus +sysevents
+.Ed
+.Pp
+This would just list the synchronizations state of
+.Xr ntpd 1ntpdmdoc
+and the major system events.
+For a simple reference server, the
+following minimum message configuration could be useful:
+.Bd -literal
+logconfig =syncall +clockall
+.Ed
+.Pp
+This configuration will list all clock information and
+synchronization information.
+All other events and messages about
+peers, system events and so on is suppressed.
+.It Ic logfile Ar logfile
+This command specifies the location of an alternate log file to
+be used instead of the default system
+.Xr syslog 3
+facility.
+This is the same operation as the -l command line option.
+.It Ic setvar Ar variable Op Cm default
+This command adds an additional system variable.
+These
+variables can be used to distribute additional information such as
+the access policy.
+If the variable of the form
+.Sm off
+.Va name = Ar value
+.Sm on
+is followed by the
+.Cm default
+keyword, the
+variable will be listed as part of the default system variables
+.Po
+.Xr ntpq 1ntpqmdoc
+.Ic rv
+command
+.Pc ) .
+These additional variables serve
+informational purposes only.
+They are not related to the protocol
+other that they can be listed.
+The known protocol variables will
+always override any variables defined via the
+.Ic setvar
+mechanism.
+There are three special variables that contain the names
+of all variable of the same group.
+The
+.Va sys_var_list
+holds
+the names of all system variables.
+The
+.Va peer_var_list
+holds
+the names of all peer variables and the
+.Va clock_var_list
+holds the names of the reference clock variables.
+.It Xo Ic tinker
+.Oo
+.Cm allan Ar allan |
+.Cm dispersion Ar dispersion |
+.Cm freq Ar freq |
+.Cm huffpuff Ar huffpuff |
+.Cm panic Ar panic |
+.Cm step Ar srep |
+.Cm stepout Ar stepout
+.Oc
+.Xc
+This command can be used to alter several system variables in
+very exceptional circumstances.
+It should occur in the
+configuration file before any other configuration options.
+The
+default values of these variables have been carefully optimized for
+a wide range of network speeds and reliability expectations.
+In
+general, they interact in intricate ways that are hard to predict
+and some combinations can result in some very nasty behavior.
+Very
+rarely is it necessary to change the default values; but, some
+folks cannot resist twisting the knobs anyway and this command is
+for them.
+Emphasis added: twisters are on their own and can expect
+no help from the support group.
+.Pp
+The variables operate as follows:
+.Bl -tag -width indent
+.It Cm allan Ar allan
+The argument becomes the new value for the minimum Allan
+intercept, which is a parameter of the PLL/FLL clock discipline
+algorithm.
+The value in log2 seconds defaults to 7 (1024 s), which is also the lower
+limit.
+.It Cm dispersion Ar dispersion
+The argument becomes the new value for the dispersion increase rate,
+normally .000015 s/s.
+.It Cm freq Ar freq
+The argument becomes the initial value of the frequency offset in
+parts-per-million.
+This overrides the value in the frequency file, if
+present, and avoids the initial training state if it is not.
+.It Cm huffpuff Ar huffpuff
+The argument becomes the new value for the experimental
+huff-n'-puff filter span, which determines the most recent interval
+the algorithm will search for a minimum delay.
+The lower limit is
+900 s (15 m), but a more reasonable value is 7200 (2 hours).
+There
+is no default, since the filter is not enabled unless this command
+is given.
+.It Cm panic Ar panic
+The argument is the panic threshold, normally 1000 s.
+If set to zero,
+the panic sanity check is disabled and a clock offset of any value will
+be accepted.
+.It Cm step Ar step
+The argument is the step threshold, which by default is 0.128 s.
+It can
+be set to any positive number in seconds.
+If set to zero, step
+adjustments will never occur.
+Note: The kernel time discipline is
+disabled if the step threshold is set to zero or greater than the
+default.
+.It Cm stepout Ar stepout
+The argument is the stepout timeout, which by default is 900 s.
+It can
+be set to any positive number in seconds.
+If set to zero, the stepout
+pulses will not be suppressed.
+.El
+.It Xo Ic trap Ar host_address
+.Op Cm port Ar port_number
+.Op Cm interface Ar interface_address
+.Xc
+This command configures a trap receiver at the given host
+address and port number for sending messages with the specified
+local interface address.
+If the port number is unspecified, a value
+of 18447 is used.
+If the interface address is not specified, the
+message is sent with a source address of the local interface the
+message is sent through.
+Note that on a multihomed host the
+interface used may vary from time to time with routing changes.
+.Pp
+The trap receiver will generally log event messages and other
+information from the server in a log file.
+While such monitor
+programs may also request their own trap dynamically, configuring a
+trap receiver will ensure that no messages are lost when the server
+is started.
+.It Cm hop Ar ...
+This command specifies a list of TTL values in increasing order, up to 8
+values can be specified.
+In manycast mode these values are used in turn in
+an expanding-ring search.
+The default is eight multiples of 32 starting at
+31.
+.El
.Sh FILES
+.Bl -tag -width /etc/ntp.drift -compact
+.It Pa /etc/ntp.conf
+the default name of the configuration file
+.It Pa ntp.keys
+private MD5 keys
+.It Pa ntpkey
+RSA private key
+.It Pa ntpkey_ Ns Ar host
+RSA public key
+.It Pa ntp_dh
+Diffie-Hellman agreement parameters
+.El
.Sh "SEE ALSO"
+.Sh SEE ALSO
+.Xr ntpd 1ntpdmdoc ,
+.Xr ntpdc 1ntpdcmdoc ,
+.Xr ntpq 1ntpqmdoc
+.Pp
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+.Li http://www.ntp.org/ .
+A snapshot of this documentation is available in HTML format in
+.Pa /usr/share/doc/ntp .
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 4)
+.%O RFC5905
+.Re
.Sh "AUTHORS"
The University of Delaware
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The syntax checking is not picky; some combinations of
+ridiculous and even hilarious options and modes may not be
+detected.
+.Pp
+The
+.Pa ntpkey_ Ns Ar host
+files are really digital
+certificates.
+These should be obtained via secure directory
+services when they become universally available.Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntp.conf\fP
option definitions.
<p>This document describes the configuration file for the NTP Project's
<code>ntpd</code> program.
- <p>This document applies to version 4.2.7p343 of <code>ntp.conf</code>.
+ <p>This document applies to version 4.2.7p344 of <code>ntp.conf</code>.
<ul class="menu">
<li><a accesskey="1" href="#ntp_002econf-Description">ntp.conf Description</a>
-.TH ntp.conf 5 "01 Jan 2013" "4.2.7p343" "File Formats"
+.TH ntp.conf 5 "03 Jan 2013" "4.2.7p344" "File Formats"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntp.man)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:33:41 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:10 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp.conf.def
.\" and the template file agman-cmd.tpl
.\"
All arguments must be options.
.PP
.SH DESCRIPTION
+The
+.B
+configuration file is read at initial startup by the
+.Xr ntpd @NTPD_MS@
+daemon in order to specify the synchronization sources,
+modes and other related information.
+Usually, it is installed in the
+.Pa /etc
+directory,
+but could be installed elsewhere
+(see the daemon's
+c
+command line option).
+.PP
+The file format is similar to other
+.Ux
+configuration files.
+Comments begin with a
+.Ql #
+character and extend to the end of the line;
+blank lines are ignored.
+Configuration commands consist of an initial keyword
+followed by a list of arguments,
+some of which may be optional, separated by whitespace.
+Commands may not be continued over multiple lines.
+Arguments may be host names,
+host addresses written in numeric, dotted-quad form,
+integers, floating point numbers (when specifying times in seconds)
+and text strings.
+.PP
+The rest of this page describes the configuration and control options.
+The
+.Qq Notes on Configuring NTP and Setting up an NTP Subnet
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+contains an extended discussion of these options.
+In addition to the discussion of general
+.Sx Configuration Options ,
+there are sections describing the following supported functionality
+and the options used to control it:
+.in +4
+.ti -4
+\fB*\fP
+
+.Sx Authentication Support
+.ti -4
+\fB*\fP
+
+.Sx Monitoring Support
+.ti -4
+\fB*\fP
+
+.Sx Access Control Support
+.ti -4
+\fB*\fP
+
+.Sx Automatic NTP Configuration Options
+.ti -4
+\fB*\fP
+
+.Sx Reference Clock Support
+.ti -4
+\fB*\fP
+
+.Sx Miscellaneous Options
+.in -4
+.PP
+Following these is a section describing
+.Sx Miscellaneous Options .
+While there is a rich set of options available,
+the only required option is one or more
+.Ic pool ,
+.Ic server ,
+.Ic peer ,
+.Ic broadcast
+or
+.Ic manycastclient
+commands.
+.SH Configuration Support
+Following is a description of the configuration commands in
+NTPv4.
+These commands have the same basic functions as in NTPv3 and
+in some cases new functions and new arguments.
+There are two
+classes of commands, configuration commands that configure a
+persistent association with a remote server or peer or reference
+clock, and auxiliary commands that specify environmental variables
+that control various related operations.
+.SS Configuration Commands
+The various modes are determined by the command keyword and the
+type of the required IP address.
+Addresses are classed by type as
+(s) a remote server or peer (IPv4 class A, B and C), (b) the
+broadcast address of a local interface, (m) a multicast address (IPv4
+class D), or (r) a reference clock address (127.127.x.x).
+Note that
+only those options applicable to each command are listed below.
+Use
+of options not listed may not be caught as an error, but may result
+in some weird and even destructive behavior.
+.PP
+If the Basic Socket Interface Extensions for IPv6 (RFC-2553)
+is detected, support for the IPv6 address family is generated
+in addition to the default support of the IPv4 address family.
+In a few cases, including the reslist billboard generated
+by ntpdc, IPv6 addresses are automatically generated.
+IPv6 addresses can be identified by the presence of colons
+.Dq \&:
+in the address field.
+IPv6 addresses can be used almost everywhere where
+IPv4 addresses can be used,
+with the exception of reference clock addresses,
+which are always IPv4.
+.PP
+Note that in contexts where a host name is expected, a
+4
+qualifier preceding
+the host name forces DNS resolution to the IPv4 namespace,
+while a
+6
+qualifier forces DNS resolution to the IPv6 namespace.
+See IPv6 references for the
+equivalent classes for that address family.
+.TP
+.BR Xo Ic pool Ar address
+[ "\fIburst\fR" ]
+[ "\fIiburst\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fImaxpoll\fR" "\fImaxpoll\fR" ]
+.Xc
+.TP
+.BR Xo Ic server Ar address
+[ "\fIkey\fR" "\fIkey\fR" \&| "\fIautokey\fR" ]
+[ "\fIburst\fR" ]
+[ "\fIiburst\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fImaxpoll\fR" "\fImaxpoll\fR" ]
+.Xc
+.TP
+.BR Xo Ic peer Ar address
+[ "\fIkey\fR" "\fIkey\fR" \&| "\fIautokey\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fImaxpoll\fR" "\fImaxpoll\fR" ]
+.Xc
+.TP
+.BR Xo Ic broadcast Ar address
+[ "\fIkey\fR" "\fIkey\fR" \&| "\fIautokey\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fIttl\fR" "\fIttl\fR" ]
+.Xc
+.TP
+.BR Xo Ic manycastclient Ar address
+[ "\fIkey\fR" "\fIkey\fR" \&| "\fIautokey\fR" ]
+[ "\fIversion\fR" "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+[ "\fIminpoll\fR" "\fIminpoll\fR" ]
+[ "\fImaxpoll\fR" "\fImaxpoll\fR" ]
+[ "\fIttl\fR" "\fIttl\fR" ]
+.Xc
+.PP
+These five commands specify the time server name or address to
+be used and the mode in which to operate.
+The
+\fIaddress\fR
+can be
+either a DNS name or an IP address in dotted-quad notation.
+Additional information on association behavior can be found in the
+.Qq Association Management
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.TP
+.BR Ic pool
+For type s addresses, this command mobilizes a persistent
+client mode association with a number of remote servers.
+In this mode the local clock can synchronized to the
+remote server, but the remote server can never be synchronized to
+the local clock.
+.TP
+.BR Ic server
+For type s and r addresses, this command mobilizes a persistent
+client mode association with the specified remote server or local
+radio clock.
+In this mode the local clock can synchronized to the
+remote server, but the remote server can never be synchronized to
+the local clock.
+This command should
+.I not
+be used for type
+b or m addresses.
+.TP
+.BR Ic peer
+For type s addresses (only), this command mobilizes a
+persistent symmetric-active mode association with the specified
+remote peer.
+In this mode the local clock can be synchronized to
+the remote peer or the remote peer can be synchronized to the local
+clock.
+This is useful in a network of servers where, depending on
+various failure scenarios, either the local or remote peer may be
+the better source of time.
+This command should NOT be used for type
+b, m or r addresses.
+.TP
+.BR Ic broadcast
+For type b and m addresses (only), this
+command mobilizes a persistent broadcast mode association.
+Multiple
+commands can be used to specify multiple local broadcast interfaces
+(subnets) and/or multiple multicast groups.
+Note that local
+broadcast messages go only to the interface associated with the
+subnet specified, but multicast messages go to all interfaces.
+In broadcast mode the local server sends periodic broadcast
+messages to a client population at the
+\fIaddress\fR
+specified, which is usually the broadcast address on (one of) the
+local network(s) or a multicast address assigned to NTP.
+The IANA
+has assigned the multicast group address IPv4 224.0.1.1 and
+IPv6 ff05::101 (site local) exclusively to
+NTP, but other nonconflicting addresses can be used to contain the
+messages within administrative boundaries.
+Ordinarily, this
+specification applies only to the local server operating as a
+sender; for operation as a broadcast client, see the
+.Ic broadcastclient
+or
+.Ic multicastclient
+commands
+below.
+.TP
+.BR Ic manycastclient
+For type m addresses (only), this command mobilizes a
+manycast client mode association for the multicast address
+specified.
+In this case a specific address must be supplied which
+matches the address used on the
+.Ic manycastserver
+command for
+the designated manycast servers.
+The NTP multicast address
+224.0.1.1 assigned by the IANA should NOT be used, unless specific
+means are taken to avoid spraying large areas of the Internet with
+these messages and causing a possibly massive implosion of replies
+at the sender.
+The
+.Ic manycastserver
+command specifies that the local server
+is to operate in client mode with the remote servers that are
+discovered as the result of broadcast/multicast messages.
+The
+client broadcasts a request message to the group address associated
+with the specified
+\fIaddress\fR
+and specifically enabled
+servers respond to these messages.
+The client selects the servers
+providing the best time and continues as with the
+.Ic server
+command.
+The remaining servers are discarded as if never
+heard.
+.PP
+Options:
+.TP
+.BR Cm autokey
+All packets sent to and received from the server or peer are to
+include authentication fields encrypted using the autokey scheme
+described in
+.Sx Authentication Options .
+.TP
+.BR Cm burst
+when the server is reachable, send a burst of eight packets
+instead of the usual one.
+The packet spacing is normally 2 s;
+however, the spacing between the first and second packets
+can be changed with the calldelay command to allow
+additional time for a modem or ISDN call to complete.
+This is designed to improve timekeeping quality
+with the
+.Ic server
+command and s addresses.
+.TP
+.BR Cm iburst
+When the server is unreachable, send a burst of eight packets
+instead of the usual one.
+The packet spacing is normally 2 s;
+however, the spacing between the first two packets can be
+changed with the calldelay command to allow
+additional time for a modem or ISDN call to complete.
+This is designed to speed the initial synchronization
+acquisition with the
+.Ic server
+command and s addresses and when
+.Xr ntpd @NTPD_MS@
+is started with the
+q
+option.
+.TP
+.BR Cm key Ar key
+All packets sent to and received from the server or peer are to
+include authentication fields encrypted using the specified
+\fIkey\fR
+identifier with values from 1 to 65534, inclusive.
+The
+default is to include no encryption field.
+.TP
+.BR Cm minpoll Ar minpoll
+.TP
+.BR Cm maxpoll Ar maxpoll
+These options specify the minimum and maximum poll intervals
+for NTP messages, as a power of 2 in seconds
+The maximum poll
+interval defaults to 10 (1,024 s), but can be increased by the
+.Cm maxpoll
+option to an upper limit of 17 (36.4 h).
+The
+minimum poll interval defaults to 6 (64 s), but can be decreased by
+the
+.Cm minpoll
+option to a lower limit of 4 (16 s).
+.TP
+.BR Cm noselect
+Marks the server as unused, except for display purposes.
+The server is discarded by the selection algroithm.
+.TP
+.BR Cm prefer
+Marks the server as preferred.
+All other things being equal,
+this host will be chosen for synchronization among a set of
+correctly operating hosts.
+See the
+.Qq Mitigation Rules and the prefer Keyword
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+for further information.
+.TP
+.BR Cm ttl Ar ttl
+This option is used only with broadcast server and manycast
+client modes.
+It specifies the time-to-live
+\fIttl\fR
+to
+use on broadcast server and multicast server and the maximum
+\fIttl\fR
+for the expanding ring search with manycast
+client packets.
+Selection of the proper value, which defaults to
+127, is something of a black art and should be coordinated with the
+network administrator.
+.TP
+.BR Cm version Ar version
+Specifies the version number to be used for outgoing NTP
+packets.
+Versions 1-4 are the choices, with version 4 the
+default.
+.SS Auxiliary Commands
+.TP
+.BR Ic broadcastclient
+This command enables reception of broadcast server messages to
+any local interface (type b) address.
+Upon receiving a message for
+the first time, the broadcast client measures the nominal server
+propagation delay using a brief client/server exchange with the
+server, then enters the broadcast client mode, in which it
+synchronizes to succeeding broadcast messages.
+Note that, in order
+to avoid accidental or malicious disruption in this mode, both the
+server and client should operate using symmetric-key or public-key
+authentication as described in
+.Sx Authentication Options .
+.TP
+.BR Ic manycastserver Ar address ...
+This command enables reception of manycast client messages to
+the multicast group address(es) (type m) specified.
+At least one
+address is required, but the NTP multicast address 224.0.1.1
+assigned by the IANA should NOT be used, unless specific means are
+taken to limit the span of the reply and avoid a possibly massive
+implosion at the original sender.
+Note that, in order to avoid
+accidental or malicious disruption in this mode, both the server
+and client should operate using symmetric-key or public-key
+authentication as described in
+.Sx Authentication Options .
+.TP
+.BR Ic multicastclient Ar address ...
+This command enables reception of multicast server messages to
+the multicast group address(es) (type m) specified.
+Upon receiving
+a message for the first time, the multicast client measures the
+nominal server propagation delay using a brief client/server
+exchange with the server, then enters the broadcast client mode, in
+which it synchronizes to succeeding multicast messages.
+Note that,
+in order to avoid accidental or malicious disruption in this mode,
+both the server and client should operate using symmetric-key or
+public-key authentication as described in
+.Sx Authentication Options .
+.SH Authentication Support
+Authentication support allows the NTP client to verify that the
+server is in fact known and trusted and not an intruder intending
+accidentally or on purpose to masquerade as that server.
+The NTPv3
+specification RFC-1305 defines a scheme which provides
+cryptographic authentication of received NTP packets.
+Originally,
+this was done using the Data Encryption Standard (DES) algorithm
+operating in Cipher Block Chaining (CBC) mode, commonly called
+DES-CBC.
+Subsequently, this was replaced by the RSA Message Digest
+5 (MD5) algorithm using a private key, commonly called keyed-MD5.
+Either algorithm computes a message digest, or one-way hash, which
+can be used to verify the server has the correct private key and
+key identifier.
+.PP
+NTPv4 retains the NTPv3 scheme, properly described as symmetric key
+cryptography and, in addition, provides a new Autokey scheme
+based on public key cryptography.
+Public key cryptography is generally considered more secure
+than symmetric key cryptography, since the security is based
+on a private value which is generated by each server and
+never revealed.
+With Autokey all key distribution and
+management functions involve only public values, which
+considerably simplifies key distribution and storage.
+Public key management is based on X.509 certificates,
+which can be provided by commercial services or
+produced by utility programs in the OpenSSL software library
+or the NTPv4 distribution.
+.PP
+While the algorithms for symmetric key cryptography are
+included in the NTPv4 distribution, public key cryptography
+requires the OpenSSL software library to be installed
+before building the NTP distribution.
+Directions for doing that
+are on the Building and Installing the Distribution page.
+.PP
+Authentication is configured separately for each association
+using the
+.Cm key
+or
+.Cm autokey
+subcommand on the
+.Ic peer ,
+.Ic server ,
+.Ic broadcast
+and
+.Ic manycastclient
+configuration commands as described in
+.Sx Configuration Options
+page.
+The authentication
+options described below specify the locations of the key files,
+if other than default, which symmetric keys are trusted
+and the interval between various operations, if other than default.
+.PP
+Authentication is always enabled,
+although ineffective if not configured as
+described below.
+If a NTP packet arrives
+including a message authentication
+code (MAC), it is accepted only if it
+passes all cryptographic checks.
+The
+checks require correct key ID, key value
+and message digest.
+If the packet has
+been modified in any way or replayed
+by an intruder, it will fail one or more
+of these checks and be discarded.
+Furthermore, the Autokey scheme requires a
+preliminary protocol exchange to obtain
+the server certificate, verify its
+credentials and initialize the protocol
+.PP
+The
+.Cm auth
+flag controls whether new associations or
+remote configuration commands require cryptographic authentication.
+This flag can be set or reset by the
+.Ic enable
+and
+.Ic disable
+commands and also by remote
+configuration commands sent by a
+.Xr ntpdc @NTPDC_MS@
+program running in
+another machine.
+If this flag is enabled, which is the default
+case, new broadcast client and symmetric passive associations and
+remote configuration commands must be cryptographically
+authenticated using either symmetric key or public key cryptography.
+If this
+flag is disabled, these operations are effective
+even if not cryptographic
+authenticated.
+It should be understood
+that operating with the
+.Ic auth
+flag disabled invites a significant vulnerability
+where a rogue hacker can
+masquerade as a falseticker and seriously
+disrupt system timekeeping.
+It is
+important to note that this flag has no purpose
+other than to allow or disallow
+a new association in response to new broadcast
+and symmetric active messages
+and remote configuration commands and, in particular,
+the flag has no effect on
+the authentication process itself.
+.PP
+An attractive alternative where multicast support is available
+is manycast mode, in which clients periodically troll
+for servers as described in the
+.Sx Automatic NTP Configuration Options
+page.
+Either symmetric key or public key
+cryptographic authentication can be used in this mode.
+The principle advantage
+of manycast mode is that potential servers need not be
+configured in advance,
+since the client finds them during regular operation,
+and the configuration
+files for all clients can be identical.
+.PP
+The security model and protocol schemes for
+both symmetric key and public key
+cryptography are summarized below;
+further details are in the briefings, papers
+and reports at the NTP project page linked from
+.Li http://www.ntp.org/ .
+.SS Symmetric-Key Cryptography
+The original RFC-1305 specification allows any one of possibly
+65,534 keys, each distinguished by a 32-bit key identifier, to
+authenticate an association.
+The servers and clients involved must
+agree on the key and key identifier to
+authenticate NTP packets.
+Keys and
+related information are specified in a key
+file, usually called
+.Pa ntp.keys ,
+which must be distributed and stored using
+secure means beyond the scope of the NTP protocol itself.
+Besides the keys used
+for ordinary NTP associations,
+additional keys can be used as passwords for the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+utility programs.
+.PP
+When
+.Xr ntpd @NTPD_MS@
+is first started, it reads the key file specified in the
+.Ic keys
+configuration command and installs the keys
+in the key cache.
+However,
+individual keys must be activated with the
+.Ic trusted
+command before use.
+This
+allows, for instance, the installation of possibly
+several batches of keys and
+then activating or deactivating each batch
+remotely using
+.Xr ntpdc @NTPDC_MS@ .
+This also provides a revocation capability that can be used
+if a key becomes compromised.
+The
+.Ic requestkey
+command selects the key used as the password for the
+.Xr ntpdc @NTPDC_MS@
+utility, while the
+.Ic controlkey
+command selects the key used as the password for the
+.Xr ntpq @NTPQ_MS@
+utility.
+.SS Public Key Cryptography
+NTPv4 supports the original NTPv3 symmetric key scheme
+described in RFC-1305 and in addition the Autokey protocol,
+which is based on public key cryptography.
+The Autokey Version 2 protocol described on the Autokey Protocol
+page verifies packet integrity using MD5 message digests
+and verifies the source with digital signatures and any of several
+digest/signature schemes.
+Optional identity schemes described on the Identity Schemes
+page and based on cryptographic challenge/response algorithms
+are also available.
+Using all of these schemes provides strong security against
+replay with or without modification, spoofing, masquerade
+and most forms of clogging attacks.
+.\" .Pp
+.\" The cryptographic means necessary for all Autokey operations
+.\" is provided by the OpenSSL software library.
+.\" This library is available from http://www.openssl.org/
+.\" and can be installed using the procedures outlined
+.\" in the Building and Installing the Distribution page.
+.\" Once installed,
+.\" the configure and build
+.\" process automatically detects the library and links
+.\" the library routines required.
+.PP
+The Autokey protocol has several modes of operation
+corresponding to the various NTP modes supported.
+Most modes use a special cookie which can be
+computed independently by the client and server,
+but encrypted in transmission.
+All modes use in addition a variant of the S-KEY scheme,
+in which a pseudo-random key list is generated and used
+in reverse order.
+These schemes are described along with an executive summary,
+current status, briefing slides and reading list on the
+.Sx Autonomous Authentication
+page.
+.PP
+The specific cryptographic environment used by Autokey servers
+and clients is determined by a set of files
+and soft links generated by the
+.Xr ntp-keygen 1ntpkeygenmdoc
+program.
+This includes a required host key file,
+required certificate file and optional sign key file,
+leapsecond file and identity scheme files.
+The
+digest/signature scheme is specified in the X.509 certificate
+along with the matching sign key.
+There are several schemes
+available in the OpenSSL software library, each identified
+by a specific string such as
+.Cm md5WithRSAEncryption ,
+which stands for the MD5 message digest with RSA
+encryption scheme.
+The current NTP distribution supports
+all the schemes in the OpenSSL library, including
+those based on RSA and DSA digital signatures.
+.PP
+NTP secure groups can be used to define cryptographic compartments
+and security hierarchies.
+It is important that every host
+in the group be able to construct a certificate trail to one
+or more trusted hosts in the same group.
+Each group
+host runs the Autokey protocol to obtain the certificates
+for all hosts along the trail to one or more trusted hosts.
+This requires the configuration file in all hosts to be
+engineered so that, even under anticipated failure conditions,
+the NTP subnet will form such that every group host can find
+a trail to at least one trusted host.
+.SS Naming and Addressing
+It is important to note that Autokey does not use DNS to
+resolve addresses, since DNS can't be completely trusted
+until the name servers have synchronized clocks.
+The cryptographic name used by Autokey to bind the host identity
+credentials and cryptographic values must be independent
+of interface, network and any other naming convention.
+The name appears in the host certificate in either or both
+the subject and issuer fields, so protection against
+DNS compromise is essential.
+.PP
+By convention, the name of an Autokey host is the name returned
+by the Unix
+.Xr gethostname 2
+system call or equivalent in other systems.
+By the system design
+model, there are no provisions to allow alternate names or aliases.
+However, this is not to say that DNS aliases, different names
+for each interface, etc., are constrained in any way.
+.PP
+It is also important to note that Autokey verifies authenticity
+using the host name, network address and public keys,
+all of which are bound together by the protocol specifically
+to deflect masquerade attacks.
+For this reason Autokey
+includes the source and destinatino IP addresses in message digest
+computations and so the same addresses must be available
+at both the server and client.
+For this reason operation
+with network address translation schemes is not possible.
+This reflects the intended robust security model where government
+and corporate NTP servers are operated outside firewall perimeters.
+.SS Operation
+A specific combination of authentication scheme (none,
+symmetric key, public key) and identity scheme is called
+a cryptotype, although not all combinations are compatible.
+There may be management configurations where the clients,
+servers and peers may not all support the same cryptotypes.
+A secure NTPv4 subnet can be configured in many ways while
+keeping in mind the principles explained above and
+in this section.
+Note however that some cryptotype
+combinations may successfully interoperate with each other,
+but may not represent good security practice.
+.PP
+The cryptotype of an association is determined at the time
+of mobilization, either at configuration time or some time
+later when a message of appropriate cryptotype arrives.
+When mobilized by a
+.Ic server
+or
+.Ic peer
+configuration command and no
+.Ic key
+or
+.Ic autokey
+subcommands are present, the association is not
+authenticated; if the
+.Ic key
+subcommand is present, the association is authenticated
+using the symmetric key ID specified; if the
+.Ic autokey
+subcommand is present, the association is authenticated
+using Autokey.
+.PP
+When multiple identity schemes are supported in the Autokey
+protocol, the first message exchange determines which one is used.
+The client request message contains bits corresponding
+to which schemes it has available.
+The server response message
+contains bits corresponding to which schemes it has available.
+Both server and client match the received bits with their own
+and select a common scheme.
+.PP
+Following the principle that time is a public value,
+a server responds to any client packet that matches
+its cryptotype capabilities.
+Thus, a server receiving
+an unauthenticated packet will respond with an unauthenticated
+packet, while the same server receiving a packet of a cryptotype
+it supports will respond with packets of that cryptotype.
+However, unconfigured broadcast or manycast client
+associations or symmetric passive associations will not be
+mobilized unless the server supports a cryptotype compatible
+with the first packet received.
+By default, unauthenticated associations will not be mobilized
+unless overridden in a decidedly dangerous way.
+.PP
+Some examples may help to reduce confusion.
+Client Alice has no specific cryptotype selected.
+Server Bob has both a symmetric key file and minimal Autokey files.
+Alice's unauthenticated messages arrive at Bob, who replies with
+unauthenticated messages.
+Cathy has a copy of Bob's symmetric
+key file and has selected key ID 4 in messages to Bob.
+Bob verifies the message with his key ID 4.
+If it's the
+same key and the message is verified, Bob sends Cathy a reply
+authenticated with that key.
+If verification fails,
+Bob sends Cathy a thing called a crypto-NAK, which tells her
+something broke.
+She can see the evidence using the
+.Xr ntpq @NTPQ_MS@
+program.
+.PP
+Denise has rolled her own host key and certificate.
+She also uses one of the identity schemes as Bob.
+She sends the first Autokey message to Bob and they
+both dance the protocol authentication and identity steps.
+If all comes out okay, Denise and Bob continue as described above.
+.PP
+It should be clear from the above that Bob can support
+all the girls at the same time, as long as he has compatible
+authentication and identity credentials.
+Now, Bob can act just like the girls in his own choice of servers;
+he can run multiple configured associations with multiple different
+servers (or the same server, although that might not be useful).
+But, wise security policy might preclude some cryptotype
+combinations; for instance, running an identity scheme
+with one server and no authentication with another might not be wise.
+.SS Key Management
+The cryptographic values used by the Autokey protocol are
+incorporated as a set of files generated by the
+.Xr ntp-keygen 1ntpkeygenmdoc
+utility program, including symmetric key, host key and
+public certificate files, as well as sign key, identity parameters
+and leapseconds files.
+Alternatively, host and sign keys and
+certificate files can be generated by the OpenSSL utilities
+and certificates can be imported from public certificate
+authorities.
+Note that symmetric keys are necessary for the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+utility programs.
+The remaining files are necessary only for the
+Autokey protocol.
+.PP
+Certificates imported from OpenSSL or public certificate
+authorities have certian limitations.
+The certificate should be in ASN.1 syntax, X.509 Version 3
+format and encoded in PEM, which is the same format
+used by OpenSSL.
+The overall length of the certificate encoded
+in ASN.1 must not exceed 1024 bytes.
+The subject distinguished
+name field (CN) is the fully qualified name of the host
+on which it is used; the remaining subject fields are ignored.
+The certificate extension fields must not contain either
+a subject key identifier or a issuer key identifier field;
+however, an extended key usage field for a trusted host must
+contain the value
+.Cm trustRoot ; .
+Other extension fields are ignored.
+.SS Authentication Commands
+.TP
+.BR Ic autokey Op Ar logsec
+Specifies the interval between regenerations of the session key
+list used with the Autokey protocol.
+Note that the size of the key
+list for each association depends on this interval and the current
+poll interval.
+The default value is 12 (4096 s or about 1.1 hours).
+For poll intervals above the specified interval, a session key list
+with a single entry will be regenerated for every message
+sent.
+.TP
+.BR Ic controlkey Ar key
+Specifies the key identifier to use with the
+.Xr ntpq @NTPQ_MS@
+utility, which uses the standard
+protocol defined in RFC-1305.
+The
+\fIkey\fR
+argument is
+the key identifier for a trusted key, where the value can be in the
+range 1 to 65,534, inclusive.
+.TP
+.BR Xo Ic crypto
+[ "\fIcert\fR" "\fIfile\fR" ]
+[ "\fIleap\fR" "\fIfile\fR" ]
+[ "\fIrandfile\fR" "\fIfile\fR" ]
+[ "\fIhost\fR" "\fIfile\fR" ]
+[ "\fIsign\fR" "\fIfile\fR" ]
+[ "\fIgq\fR" "\fIfile\fR" ]
+[ "\fIgqpar\fR" "\fIfile\fR" ]
+[ "\fIiffpar\fR" "\fIfile\fR" ]
+[ "\fImvpar\fR" "\fIfile\fR" ]
+[ "\fIpw\fR" "\fIpassword\fR" ]
+.Xc
+This command requires the OpenSSL library.
+It activates public key
+cryptography, selects the message digest and signature
+encryption scheme and loads the required private and public
+values described above.
+If one or more files are left unspecified,
+the default names are used as described above.
+Unless the complete path and name of the file are specified, the
+location of a file is relative to the keys directory specified
+in the
+.Ic keysdir
+command or default
+.Pa /usr/local/etc .
+Following are the subcommands:
+.in +4
+.ti -4
+.IR Cm cert Ar file
+Specifies the location of the required host public certificate file.
+This overrides the link
+.Pa ntpkey_cert_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm gqpar Ar file
+Specifies the location of the optional GQ parameters file.
+This
+overrides the link
+.Pa ntpkey_gq_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm host Ar file
+Specifies the location of the required host key file.
+This overrides
+the link
+.Pa ntpkey_key_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm iffpar Ar file
+Specifies the location of the optional IFF parameters file.This
+overrides the link
+.Pa ntpkey_iff_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm leap Ar file
+Specifies the location of the optional leapsecond file.
+This overrides the link
+.Pa ntpkey_leap
+in the keys directory.
+.ti -4
+.IR Cm mvpar Ar file
+Specifies the location of the optional MV parameters file.
+This
+overrides the link
+.Pa ntpkey_mv_ Ns Ar hostname
+in the keys directory.
+.ti -4
+.IR Cm pw Ar password
+Specifies the password to decrypt files containing private keys and
+identity parameters.
+This is required only if these files have been
+encrypted.
+.ti -4
+.IR Cm randfile Ar file
+Specifies the location of the random seed file used by the OpenSSL
+library.
+The defaults are described in the main text above.
+.ti -4
+.IR Cm sign Ar file
+Specifies the location of the optional sign key file.
+This overrides
+the link
+.Pa ntpkey_sign_ Ns Ar hostname
+in the keys directory.
+If this file is
+not found, the host key is also the sign key.
+.in -4
+.TP
+.BR Ic keys Ar keyfile
+Specifies the complete path and location of the MD5 key file
+containing the keys and key identifiers used by
+.Xr ntpd @NTPD_MS@ ,
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+when operating with symmetric key cryptography.
+This is the same operation as the
+k
+command line option.
+.TP
+.BR Ic keysdir Ar path
+This command specifies the default directory path for
+cryptographic keys, parameters and certificates.
+The default is
+.Pa /usr/local/etc/ .
+.TP
+.BR Ic requestkey Ar key
+Specifies the key identifier to use with the
+.Xr ntpdc @NTPDC_MS@
+utility program, which uses a
+proprietary protocol specific to this implementation of
+.Xr ntpd @NTPD_MS@ .
+The
+\fIkey\fR
+argument is a key identifier
+for the trusted key, where the value can be in the range 1 to
+65,534, inclusive.
+.TP
+.BR Ic revoke Ar logsec
+Specifies the interval between re-randomization of certain
+cryptographic values used by the Autokey scheme, as a power of 2 in
+seconds.
+These values need to be updated frequently in order to
+deflect brute-force attacks on the algorithms of the scheme;
+however, updating some values is a relatively expensive operation.
+The default interval is 16 (65,536 s or about 18 hours).
+For poll
+intervals above the specified interval, the values will be updated
+for every message sent.
+.TP
+.BR Ic trustedkey Ar key ...
+Specifies the key identifiers which are trusted for the
+purposes of authenticating peers with symmetric key cryptography,
+as well as keys used by the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+programs.
+The authentication procedures require that both the local
+and remote servers share the same key and key identifier for this
+purpose, although different keys can be used with different
+servers.
+The
+\fIkey\fR
+arguments are 32-bit unsigned
+integers with values from 1 to 65,534.
+.SS Error Codes
+The following error codes are reported via the NTP control
+and monitoring protocol trap mechanism.
+.TP
+.BR 101
+.Pq bad field format or length
+The packet has invalid version, length or format.
+.TP
+.BR 102
+.Pq bad timestamp
+The packet timestamp is the same or older than the most recent received.
+This could be due to a replay or a server clock time step.
+.TP
+.BR 103
+.Pq bad filestamp
+The packet filestamp is the same or older than the most recent received.
+This could be due to a replay or a key file generation error.
+.TP
+.BR 104
+.Pq bad or missing public key
+The public key is missing, has incorrect format or is an unsupported type.
+.TP
+.BR 105
+.Pq unsupported digest type
+The server requires an unsupported digest/signature scheme.
+.TP
+.BR 106
+.Pq mismatched digest types
+Not used.
+.TP
+.BR 107
+.Pq bad signature length
+The signature length does not match the current public key.
+.TP
+.BR 108
+.Pq signature not verified
+The message fails the signature check.
+It could be bogus or signed by a
+different private key.
+.TP
+.BR 109
+.Pq certificate not verified
+The certificate is invalid or signed with the wrong key.
+.TP
+.BR 110
+.Pq certificate not verified
+The certificate is not yet valid or has expired or the signature could not
+be verified.
+.TP
+.BR 111
+.Pq bad or missing cookie
+The cookie is missing, corrupted or bogus.
+.TP
+.BR 112
+.Pq bad or missing leapseconds table
+The leapseconds table is missing, corrupted or bogus.
+.TP
+.BR 113
+.Pq bad or missing certificate
+The certificate is missing, corrupted or bogus.
+.TP
+.BR 114
+.Pq bad or missing identity
+The identity key is missing, corrupt or bogus.
+.SH Monitoring Support
+.Xr ntpd @NTPD_MS@
+includes a comprehensive monitoring facility suitable
+for continuous, long term recording of server and client
+timekeeping performance.
+See the
+.Ic statistics
+command below
+for a listing and example of each type of statistics currently
+supported.
+Statistic files are managed using file generation sets
+and scripts in the
+.Pa ./scripts
+directory of this distribution.
+Using
+these facilities and
+.Ux
+.Xr cron 8
+jobs, the data can be
+automatically summarized and archived for retrospective analysis.
+.SS Monitoring Commands
+.TP
+.BR Ic statistics Ar name ...
+Enables writing of statistics records.
+Currently, four kinds of
+\fIname\fR
+statistics are supported.
+.in +4
+.ti -4
+.IR Cm clockstats
+Enables recording of clock driver statistics information.
+Each update
+received from a clock driver appends a line of the following form to
+the file generation set named
+.Cm clockstats :
+.br
+.in +4
+.nf
+49213 525.624 127.127.4.1 93 226 00:08:29.606 D
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The next field shows the
+clock address in dotted-quad notation.
+The final field shows the last
+timecode received from the clock in decoded ASCII format, where
+meaningful.
+In some clock drivers a good deal of additional information
+can be gathered and displayed as well.
+See information specific to each
+clock for further details.
+.ti -4
+.IR Cm cryptostats
+This option requires the OpenSSL cryptographic software library.
+It
+enables recording of cryptographic public key protocol information.
+Each message received by the protocol module appends a line of the
+following form to the file generation set named
+.Cm cryptostats :
+.br
+.in +4
+.nf
+49213 525.624 127.127.4.1 message
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The next field shows the peer
+address in dotted-quad notation, The final message field includes the
+message type and certain ancillary information.
+See the
+.Sx Authentication Options
+section for further information.
+.ti -4
+.IR Cm loopstats
+Enables recording of loop filter statistics information.
+Each
+update of the local clock outputs a line of the following form to
+the file generation set named
+.Cm loopstats :
+.br
+.in +4
+.nf
+50935 75440.031 0.000006019 13.778190 0.000351733 0.0133806
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next five fields
+show time offset (seconds), frequency offset (parts per million -
+PPM), RMS jitter (seconds), Allan deviation (PPM) and clock
+discipline time constant.
+.ti -4
+.IR Cm peerstats
+Enables recording of peer statistics information.
+This includes
+statistics records of all peers of a NTP server and of special
+signals, where present and configured.
+Each valid update appends a
+line of the following form to the current element of a file
+generation set named
+.Cm peerstats :
+.br
+.in +4
+.nf
+48773 10847.650 127.127.4.1 9714 -0.001605376 0.000000000 0.001424877 0.000958674
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next two fields
+show the peer address in dotted-quad notation and status,
+respectively.
+The status field is encoded in hex in the format
+described in Appendix A of the NTP specification RFC 1305.
+The final four fields show the offset,
+delay, dispersion and RMS jitter, all in seconds.
+.ti -4
+.IR Cm rawstats
+Enables recording of raw-timestamp statistics information.
+This
+includes statistics records of all peers of a NTP server and of
+special signals, where present and configured.
+Each NTP message
+received from a peer or clock driver appends a line of the
+following form to the file generation set named
+.Cm rawstats :
+.br
+.in +4
+.nf
+50928 2132.543 128.4.1.1 128.4.1.20 3102453281.584327000 3102453281.58622800031 02453332.540806000 3102453332.541458000
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next two fields
+show the remote peer or clock address followed by the local address
+in dotted-quad notation.
+The final four fields show the originate,
+receive, transmit and final NTP timestamps in order.
+The timestamp
+values are as received and before processing by the various data
+smoothing and mitigation algorithms.
+.ti -4
+.IR Cm sysstats
+Enables recording of ntpd statistics counters on a periodic basis.
+Each
+hour a line of the following form is appended to the file generation
+set named
+.Cm sysstats :
+.br
+.in +4
+.nf
+50928 2132.543 36000 81965 0 9546 56 71793 512 540 10 147
+.in -4
+.fi
+.PP
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The remaining ten fields show
+the statistics counter values accumulated since the last generated
+line.
+.in +4
+.ti -4
+.IR Time since restart Cm 36000
+Time in hours since the system was last rebooted.
+.ti -4
+.IR Packets received Cm 81965
+Total number of packets received.
+.ti -4
+.IR Packets processed Cm 0
+Number of packets received in response to previous packets sent
+.ti -4
+.IR Current version Cm 9546
+Number of packets matching the current NTP version.
+.ti -4
+.IR Previous version Cm 56
+Number of packets matching the previous NTP version.
+.ti -4
+.IR Bad version Cm 71793
+Number of packets matching neither NTP version.
+.ti -4
+.IR Access denied Cm 512
+Number of packets denied access for any reason.
+.ti -4
+.IR Bad length or format Cm 540
+Number of packets with invalid length, format or port number.
+.ti -4
+.IR Bad authentication Cm 10
+Number of packets not verified as authentic.
+.ti -4
+.IR Rate exceeded Cm 147
+Number of packets discarded due to rate limitation.
+.in -4
+.ti -4
+.IR Cm statsdir Ar directory_path
+Indicates the full path of a directory where statistics files
+should be created (see below).
+This keyword allows
+the (otherwise constant)
+.Cm filegen
+filename prefix to be modified for file generation sets, which
+is useful for handling statistics logs.
+.ti -4
+.IR Cm filegen Ar name Xo
+[ "\fIfile\fR" "\fIfilename\fR" ]
+[ "\fItype\fR" "\fItypename\fR" ]
+[ "\fIlink\fR" | nolink ]
+[ "\fIenable\fR" | disable ]
+.Xc
+Configures setting of generation file set name.
+Generation
+file sets provide a means for handling files that are
+continuously growing during the lifetime of a server.
+Server statistics are a typical example for such files.
+Generation file sets provide access to a set of files used
+to store the actual data.
+At any time at most one element
+of the set is being written to.
+The type given specifies
+when and how data will be directed to a new element of the set.
+This way, information stored in elements of a file set
+that are currently unused are available for administrational
+operations without the risk of disturbing the operation of ntpd.
+(Most important: they can be removed to free space for new data
+produced.)
+.PP
+Note that this command can be sent from the
+.Xr ntpdc @NTPDC_MS@
+program running at a remote location.
+.in +4
+.ti -4
+.IR Cm name
+This is the type of the statistics records, as shown in the
+.Cm statistics
+command.
+.ti -4
+.IR Cm file Ar filename
+This is the file name for the statistics records.
+Filenames of set
+members are built from three concatenated elements
+\fICm prefix ,\fR
+\fICm filename\fR
+and
+\fICm suffix :\fR
+.in +4
+.ti -4
+.IR Cm prefix
+This is a constant filename path.
+It is not subject to
+modifications via the
+\fIfilegen\fR
+option.
+It is defined by the
+server, usually specified as a compile-time constant.
+It may,
+however, be configurable for individual file generation sets
+via other commands.
+For example, the prefix used with
+\fIloopstats\fR
+and
+\fIpeerstats\fR
+generation can be configured using the
+\fIstatsdir\fR
+option explained above.
+.ti -4
+.IR Cm filename
+This string is directly concatenated to the prefix mentioned
+above (no intervening
+.Ql / ) .
+This can be modified using
+the file argument to the
+\fIfilegen\fR
+statement.
+No
+.Pa ..
+elements are
+allowed in this component to prevent filenames referring to
+parts outside the filesystem hierarchy denoted by
+\fIprefix .\fR
+.ti -4
+.IR Cm suffix
+This part is reflects individual elements of a file set.
+It is
+generated according to the type of a file set.
+.in -4
+.ti -4
+.IR Cm type Ar typename
+A file generation set is characterized by its type.
+The following
+types are supported:
+.in +4
+.ti -4
+.IR Cm none
+The file set is actually a single plain file.
+.ti -4
+.IR Cm pid
+One element of file set is used per incarnation of a ntpd
+server.
+This type does not perform any changes to file set
+members during runtime, however it provides an easy way of
+separating files belonging to different
+.Xr ntpd @NTPD_MS@
+server incarnations.
+The set member filename is built by appending a
+.Ql \&.
+to concatenated
+\fIprefix\fR
+and
+\fIfilename\fR
+strings, and
+appending the decimal representation of the process ID of the
+.Xr ntpd @NTPD_MS@
+server process.
+.ti -4
+.IR Cm day
+One file generation set element is created per day.
+A day is
+defined as the period between 00:00 and 24:00 UTC.
+The file set
+member suffix consists of a
+.Ql \&.
+and a day specification in
+the form
+.Cm YYYYMMdd .
+.Cm YYYY
+is a 4-digit year number (e.g., 1992).
+.Cm MM
+is a two digit month number.
+.Cm dd
+is a two digit day number.
+Thus, all information written at 10 December 1992 would end up
+in a file named
+\fIprefix\fR
+\fIfilename Ns .19921210 .\fR
+.ti -4
+.IR Cm week
+Any file set member contains data related to a certain week of
+a year.
+The term week is defined by computing day-of-year
+modulo 7.
+Elements of such a file generation set are
+distinguished by appending the following suffix to the file set
+filename base: A dot, a 4-digit year number, the letter
+.Cm W ,
+and a 2-digit week number.
+For example, information from January,
+10th 1992 would end up in a file with suffix
+.No . Ns Ar 1992W1 .
+.ti -4
+.IR Cm month
+One generation file set element is generated per month.
+The
+file name suffix consists of a dot, a 4-digit year number, and
+a 2-digit month.
+.ti -4
+.IR Cm year
+One generation file element is generated per year.
+The filename
+suffix consists of a dot and a 4 digit year number.
+.ti -4
+.IR Cm age
+This type of file generation sets changes to a new element of
+the file set every 24 hours of server operation.
+The filename
+suffix consists of a dot, the letter
+.Cm a ,
+and an 8-digit number.
+This number is taken to be the number of seconds the server is
+running at the start of the corresponding 24-hour period.
+Information is only written to a file generation by specifying
+.Cm enable ;
+output is prevented by specifying
+.Cm disable .
+.in -4
+.ti -4
+.IR Cm link | nolink
+It is convenient to be able to access the current element of a file
+generation set by a fixed name.
+This feature is enabled by
+specifying
+.Cm link
+and disabled using
+.Cm nolink .
+If link is specified, a
+hard link from the current file set element to a file without
+suffix is created.
+When there is already a file with this name and
+the number of links of this file is one, it is renamed appending a
+dot, the letter
+.Cm C ,
+and the pid of the ntpd server process.
+When the
+number of links is greater than one, the file is unlinked.
+This
+allows the current file to be accessed by a constant name.
+.ti -4
+.IR Cm enable \&| Cm disable
+Enables or disables the recording function.
+.in -4
+.in -4
+.SH Access Control Support
+The
+.Xr ntpd @NTPD_MS@
+daemon implements a general purpose address/mask based restriction
+list.
+The list contains address/match entries sorted first
+by increasing address values and and then by increasing mask values.
+A match occurs when the bitwise AND of the mask and the packet
+source address is equal to the bitwise AND of the mask and
+address in the list.
+The list is searched in order with the
+last match found defining the restriction flags associated
+with the entry.
+Additional information and examples can be found in the
+.Qq Notes on Configuring NTP and Setting up a NTP Subnet
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.PP
+The restriction facility was implemented in conformance
+with the access policies for the original NSFnet backbone
+time servers.
+Later the facility was expanded to deflect
+cryptographic and clogging attacks.
+While this facility may
+be useful for keeping unwanted or broken or malicious clients
+from congesting innocent servers, it should not be considered
+an alternative to the NTP authentication facilities.
+Source address based restrictions are easily circumvented
+by a determined cracker.
+.PP
+Clients can be denied service because they are explicitly
+included in the restrict list created by the restrict command
+or implicitly as the result of cryptographic or rate limit
+violations.
+Cryptographic violations include certificate
+or identity verification failure; rate limit violations generally
+result from defective NTP implementations that send packets
+at abusive rates.
+Some violations cause denied service
+only for the offending packet, others cause denied service
+for a timed period and others cause the denied service for
+an indefinate period.
+When a client or network is denied access
+for an indefinate period, the only way at present to remove
+the restrictions is by restarting the server.
+.SS The Kiss-of-Death Packet
+Ordinarily, packets denied service are simply dropped with no
+further action except incrementing statistics counters.
+Sometimes a
+more proactive response is needed, such as a server message that
+explicitly requests the client to stop sending and leave a message
+for the system operator.
+A special packet format has been created
+for this purpose called the "kiss-of-death" (KoD) packet.
+KoD packets have the leap bits set unsynchronized and stratum set
+to zero and the reference identifier field set to a four-byte
+ASCII code.
+If the
+.Cm noserve
+or
+.Cm notrust
+flag of the matching restrict list entry is set,
+the code is "DENY"; if the
+.Cm limited
+flag is set and the rate limit
+is exceeded, the code is "RATE".
+Finally, if a cryptographic violation occurs, the code is "CRYP".
+.PP
+A client receiving a KoD performs a set of sanity checks to
+minimize security exposure, then updates the stratum and
+reference identifier peer variables, sets the access
+denied (TEST4) bit in the peer flash variable and sends
+a message to the log.
+As long as the TEST4 bit is set,
+the client will send no further packets to the server.
+The only way at present to recover from this condition is
+to restart the protocol at both the client and server.
+This
+happens automatically at the client when the association times out.
+It will happen at the server only if the server operator cooperates.
+.SS Access Control Commands
+.TP
+.BR Xo Ic discard
+[ "\fIaverage\fR" "\fIavg\fR" ]
+[ "\fIminimum\fR" "\fImin\fR" ]
+[ "\fImonitor\fR" "\fIprob\fR" ]
+.Xc
+Set the parameters of the
+.Cm limited
+facility which protects the server from
+client abuse.
+The
+.Cm average
+subcommand specifies the minimum average packet
+spacing, while the
+.Cm minimum
+subcommand specifies the minimum packet spacing.
+Packets that violate these minima are discarded
+and a kiss-o'-death packet returned if enabled.
+The default
+minimum average and minimum are 5 and 2, respectively.
+The monitor subcommand specifies the probability of discard
+for packets that overflow the rate-control window.
+.TP
+.BR Xo Ic restrict address
+[ "\fImask\fR" "\fImask\fR" ]
+[ "\fIflag\fR" ... ]
+.Xc
+The
+\fIaddress\fR
+argument expressed in
+dotted-quad form is the address of a host or network.
+Alternatively, the
+\fIaddress\fR
+argument can be a valid host DNS name.
+The
+\fImask\fR
+argument expressed in dotted-quad form defaults to
+.Cm 255.255.255.255 ,
+meaning that the
+\fIaddress\fR
+is treated as the address of an individual host.
+A default entry (address
+.Cm 0.0.0.0 ,
+mask
+.Cm 0.0.0.0 )
+is always included and is always the first entry in the list.
+Note that text string
+.Cm default ,
+with no mask option, may
+be used to indicate the default entry.
+In the current implementation,
+.Cm flag
+always
+restricts access, i.e., an entry with no flags indicates that free
+access to the server is to be given.
+The flags are not orthogonal,
+in that more restrictive flags will often make less restrictive
+ones redundant.
+The flags can generally be classed into two
+categories, those which restrict time service and those which
+restrict informational queries and attempts to do run-time
+reconfiguration of the server.
+One or more of the following flags
+may be specified:
+.in +4
+.ti -4
+.IR Cm ignore
+Deny packets of all kinds, including
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+queries.
+.ti -4
+.IR Cm kod
+If this flag is set when an access violation occurs, a kiss-o'-death
+(KoD) packet is sent.
+KoD packets are rate limited to no more than one
+per second.
+If another KoD packet occurs within one second after the
+last one, the packet is dropped.
+.ti -4
+.IR Cm limited
+Deny service if the packet spacing violates the lower limits specified
+in the discard command.
+A history of clients is kept using the
+monitoring capability of
+.Xr ntpd @NTPD_MS@ .
+Thus, monitoring is always active as
+long as there is a restriction entry with the
+.Cm limited
+flag.
+.ti -4
+.IR Cm lowpriotrap
+Declare traps set by matching hosts to be low priority.
+The
+number of traps a server can maintain is limited (the current limit
+is 3).
+Traps are usually assigned on a first come, first served
+basis, with later trap requestors being denied service.
+This flag
+modifies the assignment algorithm by allowing low priority traps to
+be overridden by later requests for normal priority traps.
+.ti -4
+.IR Cm nomodify
+Deny
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+queries which attempt to modify the state of the
+server (i.e., run time reconfiguration).
+Queries which return
+information are permitted.
+.ti -4
+.IR Cm noquery
+Deny
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+queries.
+Time service is not affected.
+.ti -4
+.IR Cm nopeer
+Deny packets which would result in mobilizing a new association.
+This
+includes broadcast and symmetric active packets when a configured
+association does not exist.
+.ti -4
+.IR Cm noserve
+Deny all packets except
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+queries.
+.ti -4
+.IR Cm notrap
+Decline to provide mode 6 control message trap service to matching
+hosts.
+The trap service is a subsystem of the ntpdq control message
+protocol which is intended for use by remote event logging programs.
+.ti -4
+.IR Cm notrust
+Deny service unless the packet is cryptographically authenticated.
+.ti -4
+.IR Cm ntpport
+This is actually a match algorithm modifier, rather than a
+restriction flag.
+Its presence causes the restriction entry to be
+matched only if the source port in the packet is the standard NTP
+UDP port (123).
+Both
+.Cm ntpport
+and
+.Cm non-ntpport
+may
+be specified.
+The
+.Cm ntpport
+is considered more specific and
+is sorted later in the list.
+.ti -4
+.IR Cm version
+Deny packets that do not match the current NTP version.
+.in -4
+.PP
+Default restriction list entries with the flags ignore, interface,
+ntpport, for each of the local host's interface addresses are
+inserted into the table at startup to prevent the server
+from attempting to synchronize to its own time.
+A default entry is also always present, though if it is
+otherwise unconfigured; no flags are associated
+with the default entry (i.e., everything besides your own
+NTP server is unrestricted).
+.SH Automatic NTP Configuration Options
+.SS Manycasting
+Manycasting is a automatic discovery and configuration paradigm
+new to NTPv4.
+It is intended as a means for a multicast client
+to troll the nearby network neighborhood to find cooperating
+manycast servers, validate them using cryptographic means
+and evaluate their time values with respect to other servers
+that might be lurking in the vicinity.
+The intended result is that each manycast client mobilizes
+client associations with some number of the "best"
+of the nearby manycast servers, yet automatically reconfigures
+to sustain this number of servers should one or another fail.
+.PP
+Note that the manycasting paradigm does not coincide
+with the anycast paradigm described in RFC-1546,
+which is designed to find a single server from a clique
+of servers providing the same service.
+The manycast paradigm is designed to find a plurality
+of redundant servers satisfying defined optimality criteria.
+.PP
+Manycasting can be used with either symmetric key
+or public key cryptography.
+The public key infrastructure (PKI)
+offers the best protection against compromised keys
+and is generally considered stronger, at least with relatively
+large key sizes.
+It is implemented using the Autokey protocol and
+the OpenSSL cryptographic library available from
+.Li http://www.openssl.org/ .
+The library can also be used with other NTPv4 modes
+as well and is highly recommended, especially for broadcast modes.
+.PP
+A persistent manycast client association is configured
+using the manycastclient command, which is similar to the
+server command but with a multicast (IPv4 class
+.Cm D
+or IPv6 prefix
+.Cm FF )
+group address.
+The IANA has designated IPv4 address 224.1.1.1
+and IPv6 address FF05::101 (site local) for NTP.
+When more servers are needed, it broadcasts manycast
+client messages to this address at the minimum feasible rate
+and minimum feasible time-to-live (TTL) hops, depending
+on how many servers have already been found.
+There can be as many manycast client associations
+as different group address, each one serving as a template
+for a future ephemeral unicast client/server association.
+.PP
+Manycast servers configured with the
+.Ic manycastserver
+command listen on the specified group address for manycast
+client messages.
+Note the distinction between manycast client,
+which actively broadcasts messages, and manycast server,
+which passively responds to them.
+If a manycast server is
+in scope of the current TTL and is itself synchronized
+to a valid source and operating at a stratum level equal
+to or lower than the manycast client, it replies to the
+manycast client message with an ordinary unicast server message.
+.PP
+The manycast client receiving this message mobilizes
+an ephemeral client/server association according to the
+matching manycast client template, but only if cryptographically
+authenticated and the server stratum is less than or equal
+to the client stratum.
+Authentication is explicitly required
+and either symmetric key or public key (Autokey) can be used.
+Then, the client polls the server at its unicast address
+in burst mode in order to reliably set the host clock
+and validate the source.
+This normally results
+in a volley of eight client/server at 2-s intervals
+during which both the synchronization and cryptographic
+protocols run concurrently.
+Following the volley,
+the client runs the NTP intersection and clustering
+algorithms, which act to discard all but the "best"
+associations according to stratum and synchronization
+distance.
+The surviving associations then continue
+in ordinary client/server mode.
+.PP
+The manycast client polling strategy is designed to reduce
+as much as possible the volume of manycast client messages
+and the effects of implosion due to near-simultaneous
+arrival of manycast server messages.
+The strategy is determined by the
+.Ic manycastclient ,
+.Ic tos
+and
+.Ic ttl
+configuration commands.
+The manycast poll interval is
+normally eight times the system poll interval,
+which starts out at the
+.Cm minpoll
+value specified in the
+.Ic manycastclient ,
+command and, under normal circumstances, increments to the
+.Cm maxpolll
+value specified in this command.
+Initially, the TTL is
+set at the minimum hops specified by the ttl command.
+At each retransmission the TTL is increased until reaching
+the maximum hops specified by this command or a sufficient
+number client associations have been found.
+Further retransmissions use the same TTL.
+.PP
+The quality and reliability of the suite of associations
+discovered by the manycast client is determined by the NTP
+mitigation algorithms and the
+.Cm minclock
+and
+.Cm minsane
+values specified in the
+.Ic tos
+configuration command.
+At least
+.Cm minsane
+candidate servers must be available and the mitigation
+algorithms produce at least
+.Cm minclock
+survivors in order to synchronize the clock.
+Byzantine agreement principles require at least four
+candidates in order to correctly discard a single falseticker.
+For legacy purposes,
+.Cm minsane
+defaults to 1 and
+.Cm minclock
+defaults to 3.
+For manycast service
+.Cm minsane
+should be explicitly set to 4, assuming at least that
+number of servers are available.
+.PP
+If at least
+.Cm minclock
+servers are found, the manycast poll interval is immediately
+set to eight times
+.Cm maxpoll .
+If less than
+.Cm minclock
+servers are found when the TTL has reached the maximum hops,
+the manycast poll interval is doubled.
+For each transmission
+after that, the poll interval is doubled again until
+reaching the maximum of eight times
+.Cm maxpoll .
+Further transmissions use the same poll interval and
+TTL values.
+Note that while all this is going on,
+each client/server association found is operating normally
+it the system poll interval.
+.PP
+Administratively scoped multicast boundaries are normally
+specified by the network router configuration and,
+in the case of IPv6, the link/site scope prefix.
+By default, the increment for TTL hops is 32 starting
+from 31; however, the
+.Ic ttl
+configuration command can be
+used to modify the values to match the scope rules.
+.PP
+It is often useful to narrow the range of acceptable
+servers which can be found by manycast client associations.
+Because manycast servers respond only when the client
+stratum is equal to or greater than the server stratum,
+primary (stratum 1) servers fill find only primary servers
+in TTL range, which is probably the most common objective.
+However, unless configured otherwise, all manycast clients
+in TTL range will eventually find all primary servers
+in TTL range, which is probably not the most common
+objective in large networks.
+The
+.Ic tos
+command can be used to modify this behavior.
+Servers with stratum below
+.Cm floor
+or above
+.Cm ceiling
+specified in the
+.Ic tos
+command are strongly discouraged during the selection
+process; however, these servers may be temporally
+accepted if the number of servers within TTL range is
+less than
+.Cm minclock .
+.PP
+The above actions occur for each manycast client message,
+which repeats at the designated poll interval.
+However, once the ephemeral client association is mobilized,
+subsequent manycast server replies are discarded,
+since that would result in a duplicate association.
+If during a poll interval the number of client associations
+falls below
+.Cm minclock ,
+all manycast client prototype associations are reset
+to the initial poll interval and TTL hops and operation
+resumes from the beginning.
+It is important to avoid
+frequent manycast client messages, since each one requires
+all manycast servers in TTL range to respond.
+The result could well be an implosion, either minor or major,
+depending on the number of servers in range.
+The recommended value for
+.Cm maxpoll
+is 12 (4,096 s).
+.PP
+It is possible and frequently useful to configure a host
+as both manycast client and manycast server.
+A number of hosts configured this way and sharing a common
+group address will automatically organize themselves
+in an optimum configuration based on stratum and
+synchronization distance.
+For example, consider an NTP
+subnet of two primary servers and a hundred or more
+dependent clients.
+With two exceptions, all servers
+and clients have identical configuration files including both
+.Ic multicastclient
+and
+.Ic multicastserver
+commands using, for instance, multicast group address
+239.1.1.1.
+The only exception is that each primary server
+configuration file must include commands for the primary
+reference source such as a GPS receiver.
+.PP
+The remaining configuration files for all secondary
+servers and clients have the same contents, except for the
+.Ic tos
+command, which is specific for each stratum level.
+For stratum 1 and stratum 2 servers, that command is
+not necessary.
+For stratum 3 and above servers the
+.Cm floor
+value is set to the intended stratum number.
+Thus, all stratum 3 configuration files are identical,
+all stratum 4 files are identical and so forth.
+.PP
+Once operations have stabilized in this scenario,
+the primary servers will find the primary reference source
+and each other, since they both operate at the same
+stratum (1), but not with any secondary server or client,
+since these operate at a higher stratum.
+The secondary
+servers will find the servers at the same stratum level.
+If one of the primary servers loses its GPS receiver,
+it will continue to operate as a client and other clients
+will time out the corresponding association and
+re-associate accordingly.
+.PP
+Some administrators prefer to avoid running
+.Xr ntpd @NTPD_MS@
+continuously and run either
+.Xr ntpdate 8
+or
+.Xr ntpd @NTPD_MS@
+q
+as a cron job.
+In either case the servers must be
+configured in advance and the program fails if none are
+available when the cron job runs.
+A really slick
+application of manycast is with
+.Xr ntpd @NTPD_MS@
+q .
+The program wakes up, scans the local landscape looking
+for the usual suspects, selects the best from among
+the rascals, sets the clock and then departs.
+Servers do not have to be configured in advance and
+all clients throughout the network can have the same
+configuration file.
+.SS Manycast Interactions with Autokey
+Each time a manycast client sends a client mode packet
+to a multicast group address, all manycast servers
+in scope generate a reply including the host name
+and status word.
+The manycast clients then run
+the Autokey protocol, which collects and verifies
+all certificates involved.
+Following the burst interval
+all but three survivors are cast off,
+but the certificates remain in the local cache.
+It often happens that several complete signing trails
+from the client to the primary servers are collected in this way.
+.PP
+About once an hour or less often if the poll interval
+exceeds this, the client regenerates the Autokey key list.
+This is in general transparent in client/server mode.
+However, about once per day the server private value
+used to generate cookies is refreshed along with all
+manycast client associations.
+In this case all
+cryptographic values including certificates is refreshed.
+If a new certificate has been generated since
+the last refresh epoch, it will automatically revoke
+all prior certificates that happen to be in the
+certificate cache.
+At the same time, the manycast
+scheme starts all over from the beginning and
+the expanding ring shrinks to the minimum and increments
+from there while collecting all servers in scope.
+.SS Manycast Options
+.TP
+.BR Xo Ic tos
+.Oo
+.Cm ceiling Ar ceiling |
+.Cm cohort { 0 | 1 } |
+.Cm floor Ar floor |
+.Cm minclock Ar minclock |
+.Cm minsane Ar minsane
+.Oc
+.Xc
+This command affects the clock selection and clustering
+algorithms.
+It can be used to select the quality and
+quantity of peers used to synchronize the system clock
+and is most useful in manycast mode.
+The variables operate
+as follows:
+.in +4
+.ti -4
+.IR Cm ceiling Ar ceiling
+Peers with strata above
+.Cm ceiling
+will be discarded if there are at least
+.Cm minclock
+peers remaining.
+This value defaults to 15, but can be changed
+to any number from 1 to 15.
+.ti -4
+.IR Cm cohort Bro 0 | 1 Brc
+This is a binary flag which enables (0) or disables (1)
+manycast server replies to manycast clients with the same
+stratum level.
+This is useful to reduce implosions where
+large numbers of clients with the same stratum level
+are present.
+The default is to enable these replies.
+.ti -4
+.IR Cm floor Ar floor
+Peers with strata below
+.Cm floor
+will be discarded if there are at least
+.Cm minclock
+peers remaining.
+This value defaults to 1, but can be changed
+to any number from 1 to 15.
+.ti -4
+.IR Cm minclock Ar minclock
+The clustering algorithm repeatedly casts out outlyer
+associations until no more than
+.Cm minclock
+associations remain.
+This value defaults to 3,
+but can be changed to any number from 1 to the number of
+configured sources.
+.ti -4
+.IR Cm minsane Ar minsane
+This is the minimum number of candidates available
+to the clock selection algorithm in order to produce
+one or more truechimers for the clustering algorithm.
+If fewer than this number are available, the clock is
+undisciplined and allowed to run free.
+The default is 1
+for legacy purposes.
+However, according to principles of
+Byzantine agreement,
+.Cm minsane
+should be at least 4 in order to detect and discard
+a single falseticker.
+.in -4
+.TP
+.BR Cm ttl Ar hop ...
+This command specifies a list of TTL values in increasing
+order, up to 8 values can be specified.
+In manycast mode these values are used in turn
+in an expanding-ring search.
+The default is eight
+multiples of 32 starting at 31.
+.SH Reference Clock Support
+The NTP Version 4 daemon supports some three dozen different radio,
+satellite and modem reference clocks plus a special pseudo-clock
+used for backup or when no other clock source is available.
+Detailed descriptions of individual device drivers and options can
+be found in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+Additional information can be found in the pages linked
+there, including the
+.Qq Debugging Hints for Reference Clock Drivers
+and
+.Qq How To Write a Reference Clock Driver
+pages
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+In addition, support for a PPS
+signal is available as described in the
+.Qq Pulse-per-second (PPS) Signal Interfacing
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+Many
+drivers support special line discipline/streams modules which can
+significantly improve the accuracy using the driver.
+These are
+described in the
+.Qq Line Disciplines and Streams Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.PP
+A reference clock will generally (though not always) be a radio
+timecode receiver which is synchronized to a source of standard
+time such as the services offered by the NRC in Canada and NIST and
+USNO in the US.
+The interface between the computer and the timecode
+receiver is device dependent, but is usually a serial port.
+A
+device driver specific to each reference clock must be selected and
+compiled in the distribution; however, most common radio, satellite
+and modem clocks are included by default.
+Note that an attempt to
+configure a reference clock when the driver has not been compiled
+or the hardware port has not been appropriately configured results
+in a scalding remark to the system log file, but is otherwise non
+hazardous.
+.PP
+For the purposes of configuration,
+.Xr ntpd @NTPD_MS@
+treats
+reference clocks in a manner analogous to normal NTP peers as much
+as possible.
+Reference clocks are identified by a syntactically
+correct but invalid IP address, in order to distinguish them from
+normal NTP peers.
+Reference clock addresses are of the form
+.Sm off
+.Li 127.127. Ar t . Ar u ,
+.Sm on
+where
+\fIt\fR
+is an integer
+denoting the clock type and
+\fIu\fR
+indicates the unit
+number in the range 0-3.
+While it may seem overkill, it is in fact
+sometimes useful to configure multiple reference clocks of the same
+type, in which case the unit numbers must be unique.
+.PP
+The
+.Ic server
+command is used to configure a reference
+clock, where the
+\fIaddress\fR
+argument in that command
+is the clock address.
+The
+.Cm key ,
+.Cm version
+and
+.Cm ttl
+options are not used for reference clock support.
+The
+.Cm mode
+option is added for reference clock support, as
+described below.
+The
+.Cm prefer
+option can be useful to
+persuade the server to cherish a reference clock with somewhat more
+enthusiasm than other reference clocks or peers.
+Further
+information on this option can be found in the
+.Qq Mitigation Rules and the prefer Keyword
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page.
+The
+.Cm minpoll
+and
+.Cm maxpoll
+options have
+meaning only for selected clock drivers.
+See the individual clock
+driver document pages for additional information.
+.PP
+The
+.Ic fudge
+command is used to provide additional
+information for individual clock drivers and normally follows
+immediately after the
+.Ic server
+command.
+The
+\fIaddress\fR
+argument specifies the clock address.
+The
+.Cm refid
+and
+.Cm stratum
+options can be used to
+override the defaults for the device.
+There are two optional
+device-dependent time offsets and four flags that can be included
+in the
+.Ic fudge
+command as well.
+.PP
+The stratum number of a reference clock is by default zero.
+Since the
+.Xr ntpd @NTPD_MS@
+daemon adds one to the stratum of each
+peer, a primary server ordinarily displays an external stratum of
+one.
+In order to provide engineered backups, it is often useful to
+specify the reference clock stratum as greater than zero.
+The
+.Cm stratum
+option is used for this purpose.
+Also, in cases
+involving both a reference clock and a pulse-per-second (PPS)
+discipline signal, it is useful to specify the reference clock
+identifier as other than the default, depending on the driver.
+The
+.Cm refid
+option is used for this purpose.
+Except where noted,
+these options apply to all clock drivers.
+.SS Reference Clock Commands
+.TP
+.BR Xo Ic server
+.Sm off
+.Li 127.127. Ar t . Ar u
+.Sm on
+[ "\fIprefer\fR" ]
+[ "\fImode\fR" "\fIint\fR" ]
+[ "\fIminpoll\fR" "\fIint\fR" ]
+[ "\fImaxpoll\fR" "\fIint\fR" ]
+.Xc
+This command can be used to configure reference clocks in
+special ways.
+The options are interpreted as follows:
+.in +4
+.ti -4
+.IR Cm prefer
+Marks the reference clock as preferred.
+All other things being
+equal, this host will be chosen for synchronization among a set of
+correctly operating hosts.
+See the
+.Qq Mitigation Rules and the prefer Keyword
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+for further information.
+.ti -4
+.IR Cm mode Ar int
+Specifies a mode number which is interpreted in a
+device-specific fashion.
+For instance, it selects a dialing
+protocol in the ACTS driver and a device subtype in the
+parse
+drivers.
+.ti -4
+.IR Cm minpoll Ar int
+.ti -4
+.IR Cm maxpoll Ar int
+These options specify the minimum and maximum polling interval
+for reference clock messages, as a power of 2 in seconds
+For
+most directly connected reference clocks, both
+.Cm minpoll
+and
+.Cm maxpoll
+default to 6 (64 s).
+For modem reference clocks,
+.Cm minpoll
+defaults to 10 (17.1 m) and
+.Cm maxpoll
+defaults to 14 (4.5 h).
+The allowable range is 4 (16 s) to 17 (36.4 h) inclusive.
+.in -4
+.TP
+.BR Xo Ic fudge
+.Sm off
+.Li 127.127. Ar t . Ar u
+.Sm on
+[ "\fItime1\fR" "\fIsec\fR" ]
+[ "\fItime2\fR" "\fIsec\fR" ]
+[ "\fIstratum\fR" "\fIint\fR" ]
+[ "\fIrefid\fR" "\fIstring\fR" ]
+[ "\fImode\fR" "\fIint\fR" ]
+[ "\fIflag1\fR" "\fI0\fR" \&| "\fI1\fR" ]
+[ "\fIflag2\fR" "\fI0\fR" \&| "\fI1\fR" ]
+[ "\fIflag3\fR" "\fI0\fR" \&| "\fI1\fR" ]
+[ "\fIflag4\fR" "\fI0\fR" \&| "\fI1\fR" ]
+.Xc
+This command can be used to configure reference clocks in
+special ways.
+It must immediately follow the
+.Ic server
+command which configures the driver.
+Note that the same capability
+is possible at run time using the
+.Xr ntpdc @NTPDC_MS@
+program.
+The options are interpreted as
+follows:
+.in +4
+.ti -4
+.IR Cm time1 Ar sec
+Specifies a constant to be added to the time offset produced by
+the driver, a fixed-point decimal number in seconds.
+This is used
+as a calibration constant to adjust the nominal time offset of a
+particular clock to agree with an external standard, such as a
+precision PPS signal.
+It also provides a way to correct a
+systematic error or bias due to serial port or operating system
+latencies, different cable lengths or receiver internal delay.
+The
+specified offset is in addition to the propagation delay provided
+by other means, such as internal DIPswitches.
+Where a calibration
+for an individual system and driver is available, an approximate
+correction is noted in the driver documentation pages.
+Note: in order to facilitate calibration when more than one
+radio clock or PPS signal is supported, a special calibration
+feature is available.
+It takes the form of an argument to the
+.Ic enable
+command described in
+.Sx Miscellaneous Options
+page and operates as described in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.ti -4
+.IR Cm time2 Ar secs
+Specifies a fixed-point decimal number in seconds, which is
+interpreted in a driver-dependent way.
+See the descriptions of
+specific drivers in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.ti -4
+.IR Cm stratum Ar int
+Specifies the stratum number assigned to the driver, an integer
+between 0 and 15.
+This number overrides the default stratum number
+ordinarily assigned by the driver itself, usually zero.
+.ti -4
+.IR Cm refid Ar string
+Specifies an ASCII string of from one to four characters which
+defines the reference identifier used by the driver.
+This string
+overrides the default identifier ordinarily assigned by the driver
+itself.
+.ti -4
+.IR Cm mode Ar int
+Specifies a mode number which is interpreted in a
+device-specific fashion.
+For instance, it selects a dialing
+protocol in the ACTS driver and a device subtype in the
+parse
+drivers.
+.ti -4
+.IR Cm flag1 Cm 0 \&| Cm 1
+.ti -4
+.IR Cm flag2 Cm 0 \&| Cm 1
+.ti -4
+.IR Cm flag3 Cm 0 \&| Cm 1
+.ti -4
+.IR Cm flag4 Cm 0 \&| Cm 1
+These four flags are used for customizing the clock driver.
+The
+interpretation of these values, and whether they are used at all,
+is a function of the particular clock driver.
+However, by
+convention
+.Cm flag4
+is used to enable recording monitoring
+data to the
+.Cm clockstats
+file configured with the
+.Ic filegen
+command.
+Further information on the
+.Ic filegen
+command can be found in
+.Sx Monitoring Options .
+.in -4
+.SH Miscellaneous Options
+.TP
+.BR Ic broadcastdelay Ar seconds
+The broadcast and multicast modes require a special calibration
+to determine the network delay between the local and remote
+servers.
+Ordinarily, this is done automatically by the initial
+protocol exchanges between the client and server.
+In some cases,
+the calibration procedure may fail due to network or server access
+controls, for example.
+This command specifies the default delay to
+be used under these circumstances.
+Typically (for Ethernet), a
+number between 0.003 and 0.007 seconds is appropriate.
+The default
+when this command is not used is 0.004 seconds.
+.TP
+.BR Ic calldelay Ar delay
+This option controls the delay in seconds between the first and second
+packets sent in burst or iburst mode to allow additional time for a modem
+or ISDN call to complete.
+.TP
+.BR Ic driftfile Ar driftfile
+This command specifies the complete path and name of the file used to
+record the frequency of the local clock oscillator.
+This is the same
+operation as the
+f
+command line option.
+If the file exists, it is read at
+startup in order to set the initial frequency and then updated once per
+hour with the current frequency computed by the daemon.
+If the file name is
+specified, but the file itself does not exist, the starts with an initial
+frequency of zero and creates the file when writing it for the first time.
+If this command is not given, the daemon will always start with an initial
+frequency of zero.
+.PP
+The file format consists of a single line containing a single
+floating point number, which records the frequency offset measured
+in parts-per-million (PPM).
+The file is updated by first writing
+the current drift value into a temporary file and then renaming
+this file to replace the old version.
+This implies that
+.Xr ntpd @NTPD_MS@
+must have write permission for the directory the
+drift file is located in, and that file system links, symbolic or
+otherwise, should be avoided.
+.TP
+.BR Xo Ic enable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+.TP
+.BR Xo Ic disable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+Provides a way to enable or disable various server options.
+Flags not mentioned are unaffected.
+Note that all of these flags
+can be controlled remotely using the
+.Xr ntpdc @NTPDC_MS@
+utility program.
+.in +4
+.ti -4
+.IR Cm auth
+Enables the server to synchronize with unconfigured peers only if the
+peer has been correctly authenticated using either public key or
+private key cryptography.
+The default for this flag is
+.Ic enable .
+.ti -4
+.IR Cm bclient
+Enables the server to listen for a message from a broadcast or
+multicast server, as in the
+.Ic multicastclient
+command with default
+address.
+The default for this flag is
+.Ic disable .
+.ti -4
+.IR Cm calibrate
+Enables the calibrate feature for reference clocks.
+The default for
+this flag is
+.Ic disable .
+.ti -4
+.IR Cm kernel
+Enables the kernel time discipline, if available.
+The default for this
+flag is
+.Ic enable
+if support is available, otherwise
+.Ic disable .
+.ti -4
+.IR Cm monitor
+Enables the monitoring facility.
+See the
+.Xr ntpdc @NTPDC_MS@
+program
+and the
+.Ic monlist
+command or further information.
+The
+default for this flag is
+.Ic enable .
+.ti -4
+.IR Cm ntp
+Enables time and frequency discipline.
+In effect, this switch opens and
+closes the feedback loop, which is useful for testing.
+The default for
+this flag is
+.Ic enable .
+.ti -4
+.IR Cm pps
+Enables the pulse-per-second (PPS) signal when frequency and time is
+disciplined by the precision time kernel modifications.
+See the
+.Qq A Kernel Model for Precision Timekeeping
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page for further information.
+The default for this flag is
+.Ic disable .
+.ti -4
+.IR Cm stats
+Enables the statistics facility.
+See the
+.Sx Monitoring Options
+section for further information.
+The default for this flag is
+.Ic disable .
+.in -4
+.TP
+.BR Ic includefile Ar includefile
+This command allows additional configuration commands
+to be included from a separate file.
+Include files may
+be nested to a depth of five; upon reaching the end of any
+include file, command processing resumes in the previous
+configuration file.
+This option is useful for sites that run
+.Xr ntpd @NTPD_MS@
+on multiple hosts, with (mostly) common options (e.g., a
+restriction list).
+.TP
+.BR Ic logconfig Ar configkeyword
+This command controls the amount and type of output written to
+the system
+.Xr syslog 3
+facility or the alternate
+.Ic logfile
+log file.
+By default, all output is turned on.
+All
+\fIconfigkeyword\fR
+keywords can be prefixed with
+.Ql = ,
+.Ql +
+and
+.Ql - ,
+where
+.Ql =
+sets the
+.Xr syslog 3
+priority mask,
+.Ql +
+adds and
+.Ql -
+removes
+messages.
+.Xr syslog 3
+messages can be controlled in four
+classes
+.Po
+.Cm clock ,
+.Cm peer ,
+.Cm sys
+and
+.Cm sync
+.Pc .
+Within these classes four types of messages can be
+controlled: informational messages
+.Po
+.Cm info
+.Pc ,
+event messages
+.Po
+.Cm events
+.Pc ,
+statistics messages
+.Po
+.Cm statistics
+.Pc
+and
+status messages
+.Po
+.Cm status
+.Pc .
+.PP
+Configuration keywords are formed by concatenating the message class with
+the event class.
+The
+.Cm all
+prefix can be used instead of a message class.
+A
+message class may also be followed by the
+.Cm all
+keyword to enable/disable all
+messages of the respective message class.Thus, a minimal log configuration
+could look like this:
+.br
+.in +4
+.nf
+logconfig =syncstatus +sysevents
+.in -4
+.fi
+.PP
+This would just list the synchronizations state of
+.Xr ntpd @NTPD_MS@
+and the major system events.
+For a simple reference server, the
+following minimum message configuration could be useful:
+.br
+.in +4
+.nf
+logconfig =syncall +clockall
+.in -4
+.fi
+.PP
+This configuration will list all clock information and
+synchronization information.
+All other events and messages about
+peers, system events and so on is suppressed.
+.TP
+.BR Ic logfile Ar logfile
+This command specifies the location of an alternate log file to
+be used instead of the default system
+.Xr syslog 3
+facility.
+This is the same operation as the -l command line option.
+.TP
+.BR Ic setvar Ar variable Op Cm default
+This command adds an additional system variable.
+These
+variables can be used to distribute additional information such as
+the access policy.
+If the variable of the form
+.Sm off
+.Va name = Ar value
+.Sm on
+is followed by the
+.Cm default
+keyword, the
+variable will be listed as part of the default system variables
+.Po
+.Xr ntpq @NTPQ_MS@
+.Ic rv
+command
+.Pc ) .
+These additional variables serve
+informational purposes only.
+They are not related to the protocol
+other that they can be listed.
+The known protocol variables will
+always override any variables defined via the
+.Ic setvar
+mechanism.
+There are three special variables that contain the names
+of all variable of the same group.
+The
+.Va sys_var_list
+holds
+the names of all system variables.
+The
+.Va peer_var_list
+holds
+the names of all peer variables and the
+.Va clock_var_list
+holds the names of the reference clock variables.
+.TP
+.BR Xo Ic tinker
+.Oo
+.Cm allan Ar allan |
+.Cm dispersion Ar dispersion |
+.Cm freq Ar freq |
+.Cm huffpuff Ar huffpuff |
+.Cm panic Ar panic |
+.Cm step Ar srep |
+.Cm stepout Ar stepout
+.Oc
+.Xc
+This command can be used to alter several system variables in
+very exceptional circumstances.
+It should occur in the
+configuration file before any other configuration options.
+The
+default values of these variables have been carefully optimized for
+a wide range of network speeds and reliability expectations.
+In
+general, they interact in intricate ways that are hard to predict
+and some combinations can result in some very nasty behavior.
+Very
+rarely is it necessary to change the default values; but, some
+folks cannot resist twisting the knobs anyway and this command is
+for them.
+Emphasis added: twisters are on their own and can expect
+no help from the support group.
+.PP
+The variables operate as follows:
+.in +4
+.ti -4
+.IR Cm allan Ar allan
+The argument becomes the new value for the minimum Allan
+intercept, which is a parameter of the PLL/FLL clock discipline
+algorithm.
+The value in log2 seconds defaults to 7 (1024 s), which is also the lower
+limit.
+.ti -4
+.IR Cm dispersion Ar dispersion
+The argument becomes the new value for the dispersion increase rate,
+normally .000015 s/s.
+.ti -4
+.IR Cm freq Ar freq
+The argument becomes the initial value of the frequency offset in
+parts-per-million.
+This overrides the value in the frequency file, if
+present, and avoids the initial training state if it is not.
+.ti -4
+.IR Cm huffpuff Ar huffpuff
+The argument becomes the new value for the experimental
+huff-n'-puff filter span, which determines the most recent interval
+the algorithm will search for a minimum delay.
+The lower limit is
+900 s (15 m), but a more reasonable value is 7200 (2 hours).
+There
+is no default, since the filter is not enabled unless this command
+is given.
+.ti -4
+.IR Cm panic Ar panic
+The argument is the panic threshold, normally 1000 s.
+If set to zero,
+the panic sanity check is disabled and a clock offset of any value will
+be accepted.
+.ti -4
+.IR Cm step Ar step
+The argument is the step threshold, which by default is 0.128 s.
+It can
+be set to any positive number in seconds.
+If set to zero, step
+adjustments will never occur.
+Note: The kernel time discipline is
+disabled if the step threshold is set to zero or greater than the
+default.
+.ti -4
+.IR Cm stepout Ar stepout
+The argument is the stepout timeout, which by default is 900 s.
+It can
+be set to any positive number in seconds.
+If set to zero, the stepout
+pulses will not be suppressed.
+.in -4
+.TP
+.BR Xo Ic trap Ar host_address
+[ "\fIport\fR" "\fIport_number\fR" ]
+[ "\fIinterface\fR" "\fIinterface_address\fR" ]
+.Xc
+This command configures a trap receiver at the given host
+address and port number for sending messages with the specified
+local interface address.
+If the port number is unspecified, a value
+of 18447 is used.
+If the interface address is not specified, the
+message is sent with a source address of the local interface the
+message is sent through.
+Note that on a multihomed host the
+interface used may vary from time to time with routing changes.
+.PP
+The trap receiver will generally log event messages and other
+information from the server in a log file.
+While such monitor
+programs may also request their own trap dynamically, configuring a
+trap receiver will ensure that no messages are lost when the server
+is started.
+.TP
+.BR Cm hop Ar ...
+This command specifies a list of TTL values in increasing order, up to 8
+values can be specified.
+In manycast mode these values are used in turn in
+an expanding-ring search.
+The default is eight multiples of 32 starting at
+31.
.SH FILES
+.TP
+.BR Pa /etc/ntp.conf
+the default name of the configuration file
+.TP
+.BR Pa ntp.keys
+private MD5 keys
+.TP
+.BR Pa ntpkey
+RSA private key
+.TP
+.BR Pa ntpkey_ Ns Ar host
+RSA public key
+.TP
+.BR Pa ntp_dh
+Diffie-Hellman agreement parameters
.SH "SEE ALSO"
+.SH SEE ALSO
+.Xr ntpd @NTPD_MS@ ,
+.Xr ntpdc @NTPDC_MS@ ,
+.Xr ntpq @NTPQ_MS@
+.PP
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+.Li http://www.ntp.org/ .
+A snapshot of this documentation is available in HTML format in
+.Pa /usr/share/doc/ntp .
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 4)
+.%O RFC5905
+.Re
.SH "AUTHORS"
The University of Delaware
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The syntax checking is not picky; some combinations of
+ridiculous and even hilarious options and modes may not be
+detected.
+.PP
+The
+.Pa ntpkey_ Ns Ar host
+files are really digital
+certificates.
+These should be obtained via secure directory
+services when they become universally available.Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntp.conf\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTP_CONF 5 File Formats
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntp.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:19:44 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:31 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp.conf.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
All arguments must be options.
.Pp
.Sh DESCRIPTION
+The
+.Nm
+configuration file is read at initial startup by the
+.Xr ntpd @NTPD_MS@
+daemon in order to specify the synchronization sources,
+modes and other related information.
+Usually, it is installed in the
+.Pa /etc
+directory,
+but could be installed elsewhere
+(see the daemon's
+.Fl c
+command line option).
+.Pp
+The file format is similar to other
+.Ux
+configuration files.
+Comments begin with a
+.Ql #
+character and extend to the end of the line;
+blank lines are ignored.
+Configuration commands consist of an initial keyword
+followed by a list of arguments,
+some of which may be optional, separated by whitespace.
+Commands may not be continued over multiple lines.
+Arguments may be host names,
+host addresses written in numeric, dotted-quad form,
+integers, floating point numbers (when specifying times in seconds)
+and text strings.
+.Pp
+The rest of this page describes the configuration and control options.
+The
+.Qq Notes on Configuring NTP and Setting up an NTP Subnet
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+contains an extended discussion of these options.
+In addition to the discussion of general
+.Sx Configuration Options ,
+there are sections describing the following supported functionality
+and the options used to control it:
+.Bl -bullet -offset indent
+.It
+.Sx Authentication Support
+.It
+.Sx Monitoring Support
+.It
+.Sx Access Control Support
+.It
+.Sx Automatic NTP Configuration Options
+.It
+.Sx Reference Clock Support
+.It
+.Sx Miscellaneous Options
+.El
+.Pp
+Following these is a section describing
+.Sx Miscellaneous Options .
+While there is a rich set of options available,
+the only required option is one or more
+.Ic pool ,
+.Ic server ,
+.Ic peer ,
+.Ic broadcast
+or
+.Ic manycastclient
+commands.
+.Sh Configuration Support
+Following is a description of the configuration commands in
+NTPv4.
+These commands have the same basic functions as in NTPv3 and
+in some cases new functions and new arguments.
+There are two
+classes of commands, configuration commands that configure a
+persistent association with a remote server or peer or reference
+clock, and auxiliary commands that specify environmental variables
+that control various related operations.
+.Ss Configuration Commands
+The various modes are determined by the command keyword and the
+type of the required IP address.
+Addresses are classed by type as
+(s) a remote server or peer (IPv4 class A, B and C), (b) the
+broadcast address of a local interface, (m) a multicast address (IPv4
+class D), or (r) a reference clock address (127.127.x.x).
+Note that
+only those options applicable to each command are listed below.
+Use
+of options not listed may not be caught as an error, but may result
+in some weird and even destructive behavior.
+.Pp
+If the Basic Socket Interface Extensions for IPv6 (RFC-2553)
+is detected, support for the IPv6 address family is generated
+in addition to the default support of the IPv4 address family.
+In a few cases, including the reslist billboard generated
+by ntpdc, IPv6 addresses are automatically generated.
+IPv6 addresses can be identified by the presence of colons
+.Dq \&:
+in the address field.
+IPv6 addresses can be used almost everywhere where
+IPv4 addresses can be used,
+with the exception of reference clock addresses,
+which are always IPv4.
+.Pp
+Note that in contexts where a host name is expected, a
+.Fl 4
+qualifier preceding
+the host name forces DNS resolution to the IPv4 namespace,
+while a
+.Fl 6
+qualifier forces DNS resolution to the IPv6 namespace.
+See IPv6 references for the
+equivalent classes for that address family.
+.Bl -tag -width indent
+.It Xo Ic pool Ar address
+.Op Cm burst
+.Op Cm iburst
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm maxpoll Ar maxpoll
+.Xc
+.It Xo Ic server Ar address
+.Op Cm key Ar key \&| Cm autokey
+.Op Cm burst
+.Op Cm iburst
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm maxpoll Ar maxpoll
+.Xc
+.It Xo Ic peer Ar address
+.Op Cm key Ar key \&| Cm autokey
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm maxpoll Ar maxpoll
+.Xc
+.It Xo Ic broadcast Ar address
+.Op Cm key Ar key \&| Cm autokey
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm ttl Ar ttl
+.Xc
+.It Xo Ic manycastclient Ar address
+.Op Cm key Ar key \&| Cm autokey
+.Op Cm version Ar version
+.Op Cm prefer
+.Op Cm minpoll Ar minpoll
+.Op Cm maxpoll Ar maxpoll
+.Op Cm ttl Ar ttl
+.Xc
+.El
+.Pp
+These five commands specify the time server name or address to
+be used and the mode in which to operate.
+The
+.Ar address
+can be
+either a DNS name or an IP address in dotted-quad notation.
+Additional information on association behavior can be found in the
+.Qq Association Management
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.Bl -tag -width indent
+.It Ic pool
+For type s addresses, this command mobilizes a persistent
+client mode association with a number of remote servers.
+In this mode the local clock can synchronized to the
+remote server, but the remote server can never be synchronized to
+the local clock.
+.It Ic server
+For type s and r addresses, this command mobilizes a persistent
+client mode association with the specified remote server or local
+radio clock.
+In this mode the local clock can synchronized to the
+remote server, but the remote server can never be synchronized to
+the local clock.
+This command should
+.Em not
+be used for type
+b or m addresses.
+.It Ic peer
+For type s addresses (only), this command mobilizes a
+persistent symmetric-active mode association with the specified
+remote peer.
+In this mode the local clock can be synchronized to
+the remote peer or the remote peer can be synchronized to the local
+clock.
+This is useful in a network of servers where, depending on
+various failure scenarios, either the local or remote peer may be
+the better source of time.
+This command should NOT be used for type
+b, m or r addresses.
+.It Ic broadcast
+For type b and m addresses (only), this
+command mobilizes a persistent broadcast mode association.
+Multiple
+commands can be used to specify multiple local broadcast interfaces
+(subnets) and/or multiple multicast groups.
+Note that local
+broadcast messages go only to the interface associated with the
+subnet specified, but multicast messages go to all interfaces.
+In broadcast mode the local server sends periodic broadcast
+messages to a client population at the
+.Ar address
+specified, which is usually the broadcast address on (one of) the
+local network(s) or a multicast address assigned to NTP.
+The IANA
+has assigned the multicast group address IPv4 224.0.1.1 and
+IPv6 ff05::101 (site local) exclusively to
+NTP, but other nonconflicting addresses can be used to contain the
+messages within administrative boundaries.
+Ordinarily, this
+specification applies only to the local server operating as a
+sender; for operation as a broadcast client, see the
+.Ic broadcastclient
+or
+.Ic multicastclient
+commands
+below.
+.It Ic manycastclient
+For type m addresses (only), this command mobilizes a
+manycast client mode association for the multicast address
+specified.
+In this case a specific address must be supplied which
+matches the address used on the
+.Ic manycastserver
+command for
+the designated manycast servers.
+The NTP multicast address
+224.0.1.1 assigned by the IANA should NOT be used, unless specific
+means are taken to avoid spraying large areas of the Internet with
+these messages and causing a possibly massive implosion of replies
+at the sender.
+The
+.Ic manycastserver
+command specifies that the local server
+is to operate in client mode with the remote servers that are
+discovered as the result of broadcast/multicast messages.
+The
+client broadcasts a request message to the group address associated
+with the specified
+.Ar address
+and specifically enabled
+servers respond to these messages.
+The client selects the servers
+providing the best time and continues as with the
+.Ic server
+command.
+The remaining servers are discarded as if never
+heard.
+.El
+.Pp
+Options:
+.Bl -tag -width indent
+.It Cm autokey
+All packets sent to and received from the server or peer are to
+include authentication fields encrypted using the autokey scheme
+described in
+.Sx Authentication Options .
+.It Cm burst
+when the server is reachable, send a burst of eight packets
+instead of the usual one.
+The packet spacing is normally 2 s;
+however, the spacing between the first and second packets
+can be changed with the calldelay command to allow
+additional time for a modem or ISDN call to complete.
+This is designed to improve timekeeping quality
+with the
+.Ic server
+command and s addresses.
+.It Cm iburst
+When the server is unreachable, send a burst of eight packets
+instead of the usual one.
+The packet spacing is normally 2 s;
+however, the spacing between the first two packets can be
+changed with the calldelay command to allow
+additional time for a modem or ISDN call to complete.
+This is designed to speed the initial synchronization
+acquisition with the
+.Ic server
+command and s addresses and when
+.Xr ntpd @NTPD_MS@
+is started with the
+.Fl q
+option.
+.It Cm key Ar key
+All packets sent to and received from the server or peer are to
+include authentication fields encrypted using the specified
+.Ar key
+identifier with values from 1 to 65534, inclusive.
+The
+default is to include no encryption field.
+.It Cm minpoll Ar minpoll
+.It Cm maxpoll Ar maxpoll
+These options specify the minimum and maximum poll intervals
+for NTP messages, as a power of 2 in seconds
+The maximum poll
+interval defaults to 10 (1,024 s), but can be increased by the
+.Cm maxpoll
+option to an upper limit of 17 (36.4 h).
+The
+minimum poll interval defaults to 6 (64 s), but can be decreased by
+the
+.Cm minpoll
+option to a lower limit of 4 (16 s).
+.It Cm noselect
+Marks the server as unused, except for display purposes.
+The server is discarded by the selection algroithm.
+.It Cm prefer
+Marks the server as preferred.
+All other things being equal,
+this host will be chosen for synchronization among a set of
+correctly operating hosts.
+See the
+.Qq Mitigation Rules and the prefer Keyword
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+for further information.
+.It Cm ttl Ar ttl
+This option is used only with broadcast server and manycast
+client modes.
+It specifies the time-to-live
+.Ar ttl
+to
+use on broadcast server and multicast server and the maximum
+.Ar ttl
+for the expanding ring search with manycast
+client packets.
+Selection of the proper value, which defaults to
+127, is something of a black art and should be coordinated with the
+network administrator.
+.It Cm version Ar version
+Specifies the version number to be used for outgoing NTP
+packets.
+Versions 1-4 are the choices, with version 4 the
+default.
+.El
+.Ss Auxiliary Commands
+.Bl -tag -width indent
+.It Ic broadcastclient
+This command enables reception of broadcast server messages to
+any local interface (type b) address.
+Upon receiving a message for
+the first time, the broadcast client measures the nominal server
+propagation delay using a brief client/server exchange with the
+server, then enters the broadcast client mode, in which it
+synchronizes to succeeding broadcast messages.
+Note that, in order
+to avoid accidental or malicious disruption in this mode, both the
+server and client should operate using symmetric-key or public-key
+authentication as described in
+.Sx Authentication Options .
+.It Ic manycastserver Ar address ...
+This command enables reception of manycast client messages to
+the multicast group address(es) (type m) specified.
+At least one
+address is required, but the NTP multicast address 224.0.1.1
+assigned by the IANA should NOT be used, unless specific means are
+taken to limit the span of the reply and avoid a possibly massive
+implosion at the original sender.
+Note that, in order to avoid
+accidental or malicious disruption in this mode, both the server
+and client should operate using symmetric-key or public-key
+authentication as described in
+.Sx Authentication Options .
+.It Ic multicastclient Ar address ...
+This command enables reception of multicast server messages to
+the multicast group address(es) (type m) specified.
+Upon receiving
+a message for the first time, the multicast client measures the
+nominal server propagation delay using a brief client/server
+exchange with the server, then enters the broadcast client mode, in
+which it synchronizes to succeeding multicast messages.
+Note that,
+in order to avoid accidental or malicious disruption in this mode,
+both the server and client should operate using symmetric-key or
+public-key authentication as described in
+.Sx Authentication Options .
+.El
+.Sh Authentication Support
+Authentication support allows the NTP client to verify that the
+server is in fact known and trusted and not an intruder intending
+accidentally or on purpose to masquerade as that server.
+The NTPv3
+specification RFC-1305 defines a scheme which provides
+cryptographic authentication of received NTP packets.
+Originally,
+this was done using the Data Encryption Standard (DES) algorithm
+operating in Cipher Block Chaining (CBC) mode, commonly called
+DES-CBC.
+Subsequently, this was replaced by the RSA Message Digest
+5 (MD5) algorithm using a private key, commonly called keyed-MD5.
+Either algorithm computes a message digest, or one-way hash, which
+can be used to verify the server has the correct private key and
+key identifier.
+.Pp
+NTPv4 retains the NTPv3 scheme, properly described as symmetric key
+cryptography and, in addition, provides a new Autokey scheme
+based on public key cryptography.
+Public key cryptography is generally considered more secure
+than symmetric key cryptography, since the security is based
+on a private value which is generated by each server and
+never revealed.
+With Autokey all key distribution and
+management functions involve only public values, which
+considerably simplifies key distribution and storage.
+Public key management is based on X.509 certificates,
+which can be provided by commercial services or
+produced by utility programs in the OpenSSL software library
+or the NTPv4 distribution.
+.Pp
+While the algorithms for symmetric key cryptography are
+included in the NTPv4 distribution, public key cryptography
+requires the OpenSSL software library to be installed
+before building the NTP distribution.
+Directions for doing that
+are on the Building and Installing the Distribution page.
+.Pp
+Authentication is configured separately for each association
+using the
+.Cm key
+or
+.Cm autokey
+subcommand on the
+.Ic peer ,
+.Ic server ,
+.Ic broadcast
+and
+.Ic manycastclient
+configuration commands as described in
+.Sx Configuration Options
+page.
+The authentication
+options described below specify the locations of the key files,
+if other than default, which symmetric keys are trusted
+and the interval between various operations, if other than default.
+.Pp
+Authentication is always enabled,
+although ineffective if not configured as
+described below.
+If a NTP packet arrives
+including a message authentication
+code (MAC), it is accepted only if it
+passes all cryptographic checks.
+The
+checks require correct key ID, key value
+and message digest.
+If the packet has
+been modified in any way or replayed
+by an intruder, it will fail one or more
+of these checks and be discarded.
+Furthermore, the Autokey scheme requires a
+preliminary protocol exchange to obtain
+the server certificate, verify its
+credentials and initialize the protocol
+.Pp
+The
+.Cm auth
+flag controls whether new associations or
+remote configuration commands require cryptographic authentication.
+This flag can be set or reset by the
+.Ic enable
+and
+.Ic disable
+commands and also by remote
+configuration commands sent by a
+.Xr ntpdc @NTPDC_MS@
+program running in
+another machine.
+If this flag is enabled, which is the default
+case, new broadcast client and symmetric passive associations and
+remote configuration commands must be cryptographically
+authenticated using either symmetric key or public key cryptography.
+If this
+flag is disabled, these operations are effective
+even if not cryptographic
+authenticated.
+It should be understood
+that operating with the
+.Ic auth
+flag disabled invites a significant vulnerability
+where a rogue hacker can
+masquerade as a falseticker and seriously
+disrupt system timekeeping.
+It is
+important to note that this flag has no purpose
+other than to allow or disallow
+a new association in response to new broadcast
+and symmetric active messages
+and remote configuration commands and, in particular,
+the flag has no effect on
+the authentication process itself.
+.Pp
+An attractive alternative where multicast support is available
+is manycast mode, in which clients periodically troll
+for servers as described in the
+.Sx Automatic NTP Configuration Options
+page.
+Either symmetric key or public key
+cryptographic authentication can be used in this mode.
+The principle advantage
+of manycast mode is that potential servers need not be
+configured in advance,
+since the client finds them during regular operation,
+and the configuration
+files for all clients can be identical.
+.Pp
+The security model and protocol schemes for
+both symmetric key and public key
+cryptography are summarized below;
+further details are in the briefings, papers
+and reports at the NTP project page linked from
+.Li http://www.ntp.org/ .
+.Ss Symmetric-Key Cryptography
+The original RFC-1305 specification allows any one of possibly
+65,534 keys, each distinguished by a 32-bit key identifier, to
+authenticate an association.
+The servers and clients involved must
+agree on the key and key identifier to
+authenticate NTP packets.
+Keys and
+related information are specified in a key
+file, usually called
+.Pa ntp.keys ,
+which must be distributed and stored using
+secure means beyond the scope of the NTP protocol itself.
+Besides the keys used
+for ordinary NTP associations,
+additional keys can be used as passwords for the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+utility programs.
+.Pp
+When
+.Xr ntpd @NTPD_MS@
+is first started, it reads the key file specified in the
+.Ic keys
+configuration command and installs the keys
+in the key cache.
+However,
+individual keys must be activated with the
+.Ic trusted
+command before use.
+This
+allows, for instance, the installation of possibly
+several batches of keys and
+then activating or deactivating each batch
+remotely using
+.Xr ntpdc @NTPDC_MS@ .
+This also provides a revocation capability that can be used
+if a key becomes compromised.
+The
+.Ic requestkey
+command selects the key used as the password for the
+.Xr ntpdc @NTPDC_MS@
+utility, while the
+.Ic controlkey
+command selects the key used as the password for the
+.Xr ntpq @NTPQ_MS@
+utility.
+.Ss Public Key Cryptography
+NTPv4 supports the original NTPv3 symmetric key scheme
+described in RFC-1305 and in addition the Autokey protocol,
+which is based on public key cryptography.
+The Autokey Version 2 protocol described on the Autokey Protocol
+page verifies packet integrity using MD5 message digests
+and verifies the source with digital signatures and any of several
+digest/signature schemes.
+Optional identity schemes described on the Identity Schemes
+page and based on cryptographic challenge/response algorithms
+are also available.
+Using all of these schemes provides strong security against
+replay with or without modification, spoofing, masquerade
+and most forms of clogging attacks.
+.\" .Pp
+.\" The cryptographic means necessary for all Autokey operations
+.\" is provided by the OpenSSL software library.
+.\" This library is available from http://www.openssl.org/
+.\" and can be installed using the procedures outlined
+.\" in the Building and Installing the Distribution page.
+.\" Once installed,
+.\" the configure and build
+.\" process automatically detects the library and links
+.\" the library routines required.
+.Pp
+The Autokey protocol has several modes of operation
+corresponding to the various NTP modes supported.
+Most modes use a special cookie which can be
+computed independently by the client and server,
+but encrypted in transmission.
+All modes use in addition a variant of the S-KEY scheme,
+in which a pseudo-random key list is generated and used
+in reverse order.
+These schemes are described along with an executive summary,
+current status, briefing slides and reading list on the
+.Sx Autonomous Authentication
+page.
+.Pp
+The specific cryptographic environment used by Autokey servers
+and clients is determined by a set of files
+and soft links generated by the
+.Xr ntp-keygen 1ntpkeygenmdoc
+program.
+This includes a required host key file,
+required certificate file and optional sign key file,
+leapsecond file and identity scheme files.
+The
+digest/signature scheme is specified in the X.509 certificate
+along with the matching sign key.
+There are several schemes
+available in the OpenSSL software library, each identified
+by a specific string such as
+.Cm md5WithRSAEncryption ,
+which stands for the MD5 message digest with RSA
+encryption scheme.
+The current NTP distribution supports
+all the schemes in the OpenSSL library, including
+those based on RSA and DSA digital signatures.
+.Pp
+NTP secure groups can be used to define cryptographic compartments
+and security hierarchies.
+It is important that every host
+in the group be able to construct a certificate trail to one
+or more trusted hosts in the same group.
+Each group
+host runs the Autokey protocol to obtain the certificates
+for all hosts along the trail to one or more trusted hosts.
+This requires the configuration file in all hosts to be
+engineered so that, even under anticipated failure conditions,
+the NTP subnet will form such that every group host can find
+a trail to at least one trusted host.
+.Ss Naming and Addressing
+It is important to note that Autokey does not use DNS to
+resolve addresses, since DNS can't be completely trusted
+until the name servers have synchronized clocks.
+The cryptographic name used by Autokey to bind the host identity
+credentials and cryptographic values must be independent
+of interface, network and any other naming convention.
+The name appears in the host certificate in either or both
+the subject and issuer fields, so protection against
+DNS compromise is essential.
+.Pp
+By convention, the name of an Autokey host is the name returned
+by the Unix
+.Xr gethostname 2
+system call or equivalent in other systems.
+By the system design
+model, there are no provisions to allow alternate names or aliases.
+However, this is not to say that DNS aliases, different names
+for each interface, etc., are constrained in any way.
+.Pp
+It is also important to note that Autokey verifies authenticity
+using the host name, network address and public keys,
+all of which are bound together by the protocol specifically
+to deflect masquerade attacks.
+For this reason Autokey
+includes the source and destinatino IP addresses in message digest
+computations and so the same addresses must be available
+at both the server and client.
+For this reason operation
+with network address translation schemes is not possible.
+This reflects the intended robust security model where government
+and corporate NTP servers are operated outside firewall perimeters.
+.Ss Operation
+A specific combination of authentication scheme (none,
+symmetric key, public key) and identity scheme is called
+a cryptotype, although not all combinations are compatible.
+There may be management configurations where the clients,
+servers and peers may not all support the same cryptotypes.
+A secure NTPv4 subnet can be configured in many ways while
+keeping in mind the principles explained above and
+in this section.
+Note however that some cryptotype
+combinations may successfully interoperate with each other,
+but may not represent good security practice.
+.Pp
+The cryptotype of an association is determined at the time
+of mobilization, either at configuration time or some time
+later when a message of appropriate cryptotype arrives.
+When mobilized by a
+.Ic server
+or
+.Ic peer
+configuration command and no
+.Ic key
+or
+.Ic autokey
+subcommands are present, the association is not
+authenticated; if the
+.Ic key
+subcommand is present, the association is authenticated
+using the symmetric key ID specified; if the
+.Ic autokey
+subcommand is present, the association is authenticated
+using Autokey.
+.Pp
+When multiple identity schemes are supported in the Autokey
+protocol, the first message exchange determines which one is used.
+The client request message contains bits corresponding
+to which schemes it has available.
+The server response message
+contains bits corresponding to which schemes it has available.
+Both server and client match the received bits with their own
+and select a common scheme.
+.Pp
+Following the principle that time is a public value,
+a server responds to any client packet that matches
+its cryptotype capabilities.
+Thus, a server receiving
+an unauthenticated packet will respond with an unauthenticated
+packet, while the same server receiving a packet of a cryptotype
+it supports will respond with packets of that cryptotype.
+However, unconfigured broadcast or manycast client
+associations or symmetric passive associations will not be
+mobilized unless the server supports a cryptotype compatible
+with the first packet received.
+By default, unauthenticated associations will not be mobilized
+unless overridden in a decidedly dangerous way.
+.Pp
+Some examples may help to reduce confusion.
+Client Alice has no specific cryptotype selected.
+Server Bob has both a symmetric key file and minimal Autokey files.
+Alice's unauthenticated messages arrive at Bob, who replies with
+unauthenticated messages.
+Cathy has a copy of Bob's symmetric
+key file and has selected key ID 4 in messages to Bob.
+Bob verifies the message with his key ID 4.
+If it's the
+same key and the message is verified, Bob sends Cathy a reply
+authenticated with that key.
+If verification fails,
+Bob sends Cathy a thing called a crypto-NAK, which tells her
+something broke.
+She can see the evidence using the
+.Xr ntpq @NTPQ_MS@
+program.
+.Pp
+Denise has rolled her own host key and certificate.
+She also uses one of the identity schemes as Bob.
+She sends the first Autokey message to Bob and they
+both dance the protocol authentication and identity steps.
+If all comes out okay, Denise and Bob continue as described above.
+.Pp
+It should be clear from the above that Bob can support
+all the girls at the same time, as long as he has compatible
+authentication and identity credentials.
+Now, Bob can act just like the girls in his own choice of servers;
+he can run multiple configured associations with multiple different
+servers (or the same server, although that might not be useful).
+But, wise security policy might preclude some cryptotype
+combinations; for instance, running an identity scheme
+with one server and no authentication with another might not be wise.
+.Ss Key Management
+The cryptographic values used by the Autokey protocol are
+incorporated as a set of files generated by the
+.Xr ntp-keygen 1ntpkeygenmdoc
+utility program, including symmetric key, host key and
+public certificate files, as well as sign key, identity parameters
+and leapseconds files.
+Alternatively, host and sign keys and
+certificate files can be generated by the OpenSSL utilities
+and certificates can be imported from public certificate
+authorities.
+Note that symmetric keys are necessary for the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+utility programs.
+The remaining files are necessary only for the
+Autokey protocol.
+.Pp
+Certificates imported from OpenSSL or public certificate
+authorities have certian limitations.
+The certificate should be in ASN.1 syntax, X.509 Version 3
+format and encoded in PEM, which is the same format
+used by OpenSSL.
+The overall length of the certificate encoded
+in ASN.1 must not exceed 1024 bytes.
+The subject distinguished
+name field (CN) is the fully qualified name of the host
+on which it is used; the remaining subject fields are ignored.
+The certificate extension fields must not contain either
+a subject key identifier or a issuer key identifier field;
+however, an extended key usage field for a trusted host must
+contain the value
+.Cm trustRoot ; .
+Other extension fields are ignored.
+.Ss Authentication Commands
+.Bl -tag -width indent
+.It Ic autokey Op Ar logsec
+Specifies the interval between regenerations of the session key
+list used with the Autokey protocol.
+Note that the size of the key
+list for each association depends on this interval and the current
+poll interval.
+The default value is 12 (4096 s or about 1.1 hours).
+For poll intervals above the specified interval, a session key list
+with a single entry will be regenerated for every message
+sent.
+.It Ic controlkey Ar key
+Specifies the key identifier to use with the
+.Xr ntpq @NTPQ_MS@
+utility, which uses the standard
+protocol defined in RFC-1305.
+The
+.Ar key
+argument is
+the key identifier for a trusted key, where the value can be in the
+range 1 to 65,534, inclusive.
+.It Xo Ic crypto
+.Op Cm cert Ar file
+.Op Cm leap Ar file
+.Op Cm randfile Ar file
+.Op Cm host Ar file
+.Op Cm sign Ar file
+.Op Cm gq Ar file
+.Op Cm gqpar Ar file
+.Op Cm iffpar Ar file
+.Op Cm mvpar Ar file
+.Op Cm pw Ar password
+.Xc
+This command requires the OpenSSL library.
+It activates public key
+cryptography, selects the message digest and signature
+encryption scheme and loads the required private and public
+values described above.
+If one or more files are left unspecified,
+the default names are used as described above.
+Unless the complete path and name of the file are specified, the
+location of a file is relative to the keys directory specified
+in the
+.Ic keysdir
+command or default
+.Pa /usr/local/etc .
+Following are the subcommands:
+.Bl -tag -width indent
+.It Cm cert Ar file
+Specifies the location of the required host public certificate file.
+This overrides the link
+.Pa ntpkey_cert_ Ns Ar hostname
+in the keys directory.
+.It Cm gqpar Ar file
+Specifies the location of the optional GQ parameters file.
+This
+overrides the link
+.Pa ntpkey_gq_ Ns Ar hostname
+in the keys directory.
+.It Cm host Ar file
+Specifies the location of the required host key file.
+This overrides
+the link
+.Pa ntpkey_key_ Ns Ar hostname
+in the keys directory.
+.It Cm iffpar Ar file
+Specifies the location of the optional IFF parameters file.This
+overrides the link
+.Pa ntpkey_iff_ Ns Ar hostname
+in the keys directory.
+.It Cm leap Ar file
+Specifies the location of the optional leapsecond file.
+This overrides the link
+.Pa ntpkey_leap
+in the keys directory.
+.It Cm mvpar Ar file
+Specifies the location of the optional MV parameters file.
+This
+overrides the link
+.Pa ntpkey_mv_ Ns Ar hostname
+in the keys directory.
+.It Cm pw Ar password
+Specifies the password to decrypt files containing private keys and
+identity parameters.
+This is required only if these files have been
+encrypted.
+.It Cm randfile Ar file
+Specifies the location of the random seed file used by the OpenSSL
+library.
+The defaults are described in the main text above.
+.It Cm sign Ar file
+Specifies the location of the optional sign key file.
+This overrides
+the link
+.Pa ntpkey_sign_ Ns Ar hostname
+in the keys directory.
+If this file is
+not found, the host key is also the sign key.
+.El
+.It Ic keys Ar keyfile
+Specifies the complete path and location of the MD5 key file
+containing the keys and key identifiers used by
+.Xr ntpd @NTPD_MS@ ,
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+when operating with symmetric key cryptography.
+This is the same operation as the
+.Fl k
+command line option.
+.It Ic keysdir Ar path
+This command specifies the default directory path for
+cryptographic keys, parameters and certificates.
+The default is
+.Pa /usr/local/etc/ .
+.It Ic requestkey Ar key
+Specifies the key identifier to use with the
+.Xr ntpdc @NTPDC_MS@
+utility program, which uses a
+proprietary protocol specific to this implementation of
+.Xr ntpd @NTPD_MS@ .
+The
+.Ar key
+argument is a key identifier
+for the trusted key, where the value can be in the range 1 to
+65,534, inclusive.
+.It Ic revoke Ar logsec
+Specifies the interval between re-randomization of certain
+cryptographic values used by the Autokey scheme, as a power of 2 in
+seconds.
+These values need to be updated frequently in order to
+deflect brute-force attacks on the algorithms of the scheme;
+however, updating some values is a relatively expensive operation.
+The default interval is 16 (65,536 s or about 18 hours).
+For poll
+intervals above the specified interval, the values will be updated
+for every message sent.
+.It Ic trustedkey Ar key ...
+Specifies the key identifiers which are trusted for the
+purposes of authenticating peers with symmetric key cryptography,
+as well as keys used by the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+programs.
+The authentication procedures require that both the local
+and remote servers share the same key and key identifier for this
+purpose, although different keys can be used with different
+servers.
+The
+.Ar key
+arguments are 32-bit unsigned
+integers with values from 1 to 65,534.
+.El
+.Ss Error Codes
+The following error codes are reported via the NTP control
+and monitoring protocol trap mechanism.
+.Bl -tag -width indent
+.It 101
+.Pq bad field format or length
+The packet has invalid version, length or format.
+.It 102
+.Pq bad timestamp
+The packet timestamp is the same or older than the most recent received.
+This could be due to a replay or a server clock time step.
+.It 103
+.Pq bad filestamp
+The packet filestamp is the same or older than the most recent received.
+This could be due to a replay or a key file generation error.
+.It 104
+.Pq bad or missing public key
+The public key is missing, has incorrect format or is an unsupported type.
+.It 105
+.Pq unsupported digest type
+The server requires an unsupported digest/signature scheme.
+.It 106
+.Pq mismatched digest types
+Not used.
+.It 107
+.Pq bad signature length
+The signature length does not match the current public key.
+.It 108
+.Pq signature not verified
+The message fails the signature check.
+It could be bogus or signed by a
+different private key.
+.It 109
+.Pq certificate not verified
+The certificate is invalid or signed with the wrong key.
+.It 110
+.Pq certificate not verified
+The certificate is not yet valid or has expired or the signature could not
+be verified.
+.It 111
+.Pq bad or missing cookie
+The cookie is missing, corrupted or bogus.
+.It 112
+.Pq bad or missing leapseconds table
+The leapseconds table is missing, corrupted or bogus.
+.It 113
+.Pq bad or missing certificate
+The certificate is missing, corrupted or bogus.
+.It 114
+.Pq bad or missing identity
+The identity key is missing, corrupt or bogus.
+.El
+.Sh Monitoring Support
+.Xr ntpd @NTPD_MS@
+includes a comprehensive monitoring facility suitable
+for continuous, long term recording of server and client
+timekeeping performance.
+See the
+.Ic statistics
+command below
+for a listing and example of each type of statistics currently
+supported.
+Statistic files are managed using file generation sets
+and scripts in the
+.Pa ./scripts
+directory of this distribution.
+Using
+these facilities and
+.Ux
+.Xr cron 8
+jobs, the data can be
+automatically summarized and archived for retrospective analysis.
+.Ss Monitoring Commands
+.Bl -tag -width indent
+.It Ic statistics Ar name ...
+Enables writing of statistics records.
+Currently, four kinds of
+.Ar name
+statistics are supported.
+.Bl -tag -width indent
+.It Cm clockstats
+Enables recording of clock driver statistics information.
+Each update
+received from a clock driver appends a line of the following form to
+the file generation set named
+.Cm clockstats :
+.Bd -literal
+49213 525.624 127.127.4.1 93 226 00:08:29.606 D
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The next field shows the
+clock address in dotted-quad notation.
+The final field shows the last
+timecode received from the clock in decoded ASCII format, where
+meaningful.
+In some clock drivers a good deal of additional information
+can be gathered and displayed as well.
+See information specific to each
+clock for further details.
+.It Cm cryptostats
+This option requires the OpenSSL cryptographic software library.
+It
+enables recording of cryptographic public key protocol information.
+Each message received by the protocol module appends a line of the
+following form to the file generation set named
+.Cm cryptostats :
+.Bd -literal
+49213 525.624 127.127.4.1 message
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The next field shows the peer
+address in dotted-quad notation, The final message field includes the
+message type and certain ancillary information.
+See the
+.Sx Authentication Options
+section for further information.
+.It Cm loopstats
+Enables recording of loop filter statistics information.
+Each
+update of the local clock outputs a line of the following form to
+the file generation set named
+.Cm loopstats :
+.Bd -literal
+50935 75440.031 0.000006019 13.778190 0.000351733 0.0133806
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next five fields
+show time offset (seconds), frequency offset (parts per million -
+PPM), RMS jitter (seconds), Allan deviation (PPM) and clock
+discipline time constant.
+.It Cm peerstats
+Enables recording of peer statistics information.
+This includes
+statistics records of all peers of a NTP server and of special
+signals, where present and configured.
+Each valid update appends a
+line of the following form to the current element of a file
+generation set named
+.Cm peerstats :
+.Bd -literal
+48773 10847.650 127.127.4.1 9714 -0.001605376 0.000000000 0.001424877 0.000958674
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next two fields
+show the peer address in dotted-quad notation and status,
+respectively.
+The status field is encoded in hex in the format
+described in Appendix A of the NTP specification RFC 1305.
+The final four fields show the offset,
+delay, dispersion and RMS jitter, all in seconds.
+.It Cm rawstats
+Enables recording of raw-timestamp statistics information.
+This
+includes statistics records of all peers of a NTP server and of
+special signals, where present and configured.
+Each NTP message
+received from a peer or clock driver appends a line of the
+following form to the file generation set named
+.Cm rawstats :
+.Bd -literal
+50928 2132.543 128.4.1.1 128.4.1.20 3102453281.584327000 3102453281.58622800031 02453332.540806000 3102453332.541458000
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and
+time (seconds and fraction past UTC midnight).
+The next two fields
+show the remote peer or clock address followed by the local address
+in dotted-quad notation.
+The final four fields show the originate,
+receive, transmit and final NTP timestamps in order.
+The timestamp
+values are as received and before processing by the various data
+smoothing and mitigation algorithms.
+.It Cm sysstats
+Enables recording of ntpd statistics counters on a periodic basis.
+Each
+hour a line of the following form is appended to the file generation
+set named
+.Cm sysstats :
+.Bd -literal
+50928 2132.543 36000 81965 0 9546 56 71793 512 540 10 147
+.Ed
+.Pp
+The first two fields show the date (Modified Julian Day) and time
+(seconds and fraction past UTC midnight).
+The remaining ten fields show
+the statistics counter values accumulated since the last generated
+line.
+.Bl -tag -width indent
+.It Time since restart Cm 36000
+Time in hours since the system was last rebooted.
+.It Packets received Cm 81965
+Total number of packets received.
+.It Packets processed Cm 0
+Number of packets received in response to previous packets sent
+.It Current version Cm 9546
+Number of packets matching the current NTP version.
+.It Previous version Cm 56
+Number of packets matching the previous NTP version.
+.It Bad version Cm 71793
+Number of packets matching neither NTP version.
+.It Access denied Cm 512
+Number of packets denied access for any reason.
+.It Bad length or format Cm 540
+Number of packets with invalid length, format or port number.
+.It Bad authentication Cm 10
+Number of packets not verified as authentic.
+.It Rate exceeded Cm 147
+Number of packets discarded due to rate limitation.
+.El
+.It Cm statsdir Ar directory_path
+Indicates the full path of a directory where statistics files
+should be created (see below).
+This keyword allows
+the (otherwise constant)
+.Cm filegen
+filename prefix to be modified for file generation sets, which
+is useful for handling statistics logs.
+.It Cm filegen Ar name Xo
+.Op Cm file Ar filename
+.Op Cm type Ar typename
+.Op Cm link | nolink
+.Op Cm enable | disable
+.Xc
+Configures setting of generation file set name.
+Generation
+file sets provide a means for handling files that are
+continuously growing during the lifetime of a server.
+Server statistics are a typical example for such files.
+Generation file sets provide access to a set of files used
+to store the actual data.
+At any time at most one element
+of the set is being written to.
+The type given specifies
+when and how data will be directed to a new element of the set.
+This way, information stored in elements of a file set
+that are currently unused are available for administrational
+operations without the risk of disturbing the operation of ntpd.
+(Most important: they can be removed to free space for new data
+produced.)
+.Pp
+Note that this command can be sent from the
+.Xr ntpdc @NTPDC_MS@
+program running at a remote location.
+.Bl -tag -width indent
+.It Cm name
+This is the type of the statistics records, as shown in the
+.Cm statistics
+command.
+.It Cm file Ar filename
+This is the file name for the statistics records.
+Filenames of set
+members are built from three concatenated elements
+.Ar Cm prefix ,
+.Ar Cm filename
+and
+.Ar Cm suffix :
+.Bl -tag -width indent
+.It Cm prefix
+This is a constant filename path.
+It is not subject to
+modifications via the
+.Ar filegen
+option.
+It is defined by the
+server, usually specified as a compile-time constant.
+It may,
+however, be configurable for individual file generation sets
+via other commands.
+For example, the prefix used with
+.Ar loopstats
+and
+.Ar peerstats
+generation can be configured using the
+.Ar statsdir
+option explained above.
+.It Cm filename
+This string is directly concatenated to the prefix mentioned
+above (no intervening
+.Ql / ) .
+This can be modified using
+the file argument to the
+.Ar filegen
+statement.
+No
+.Pa ..
+elements are
+allowed in this component to prevent filenames referring to
+parts outside the filesystem hierarchy denoted by
+.Ar prefix .
+.It Cm suffix
+This part is reflects individual elements of a file set.
+It is
+generated according to the type of a file set.
+.El
+.It Cm type Ar typename
+A file generation set is characterized by its type.
+The following
+types are supported:
+.Bl -tag -width indent
+.It Cm none
+The file set is actually a single plain file.
+.It Cm pid
+One element of file set is used per incarnation of a ntpd
+server.
+This type does not perform any changes to file set
+members during runtime, however it provides an easy way of
+separating files belonging to different
+.Xr ntpd @NTPD_MS@
+server incarnations.
+The set member filename is built by appending a
+.Ql \&.
+to concatenated
+.Ar prefix
+and
+.Ar filename
+strings, and
+appending the decimal representation of the process ID of the
+.Xr ntpd @NTPD_MS@
+server process.
+.It Cm day
+One file generation set element is created per day.
+A day is
+defined as the period between 00:00 and 24:00 UTC.
+The file set
+member suffix consists of a
+.Ql \&.
+and a day specification in
+the form
+.Cm YYYYMMdd .
+.Cm YYYY
+is a 4-digit year number (e.g., 1992).
+.Cm MM
+is a two digit month number.
+.Cm dd
+is a two digit day number.
+Thus, all information written at 10 December 1992 would end up
+in a file named
+.Ar prefix
+.Ar filename Ns .19921210 .
+.It Cm week
+Any file set member contains data related to a certain week of
+a year.
+The term week is defined by computing day-of-year
+modulo 7.
+Elements of such a file generation set are
+distinguished by appending the following suffix to the file set
+filename base: A dot, a 4-digit year number, the letter
+.Cm W ,
+and a 2-digit week number.
+For example, information from January,
+10th 1992 would end up in a file with suffix
+.No . Ns Ar 1992W1 .
+.It Cm month
+One generation file set element is generated per month.
+The
+file name suffix consists of a dot, a 4-digit year number, and
+a 2-digit month.
+.It Cm year
+One generation file element is generated per year.
+The filename
+suffix consists of a dot and a 4 digit year number.
+.It Cm age
+This type of file generation sets changes to a new element of
+the file set every 24 hours of server operation.
+The filename
+suffix consists of a dot, the letter
+.Cm a ,
+and an 8-digit number.
+This number is taken to be the number of seconds the server is
+running at the start of the corresponding 24-hour period.
+Information is only written to a file generation by specifying
+.Cm enable ;
+output is prevented by specifying
+.Cm disable .
+.El
+.It Cm link | nolink
+It is convenient to be able to access the current element of a file
+generation set by a fixed name.
+This feature is enabled by
+specifying
+.Cm link
+and disabled using
+.Cm nolink .
+If link is specified, a
+hard link from the current file set element to a file without
+suffix is created.
+When there is already a file with this name and
+the number of links of this file is one, it is renamed appending a
+dot, the letter
+.Cm C ,
+and the pid of the ntpd server process.
+When the
+number of links is greater than one, the file is unlinked.
+This
+allows the current file to be accessed by a constant name.
+.It Cm enable \&| Cm disable
+Enables or disables the recording function.
+.El
+.El
+.El
+.Sh Access Control Support
+The
+.Xr ntpd @NTPD_MS@
+daemon implements a general purpose address/mask based restriction
+list.
+The list contains address/match entries sorted first
+by increasing address values and and then by increasing mask values.
+A match occurs when the bitwise AND of the mask and the packet
+source address is equal to the bitwise AND of the mask and
+address in the list.
+The list is searched in order with the
+last match found defining the restriction flags associated
+with the entry.
+Additional information and examples can be found in the
+.Qq Notes on Configuring NTP and Setting up a NTP Subnet
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.Pp
+The restriction facility was implemented in conformance
+with the access policies for the original NSFnet backbone
+time servers.
+Later the facility was expanded to deflect
+cryptographic and clogging attacks.
+While this facility may
+be useful for keeping unwanted or broken or malicious clients
+from congesting innocent servers, it should not be considered
+an alternative to the NTP authentication facilities.
+Source address based restrictions are easily circumvented
+by a determined cracker.
+.Pp
+Clients can be denied service because they are explicitly
+included in the restrict list created by the restrict command
+or implicitly as the result of cryptographic or rate limit
+violations.
+Cryptographic violations include certificate
+or identity verification failure; rate limit violations generally
+result from defective NTP implementations that send packets
+at abusive rates.
+Some violations cause denied service
+only for the offending packet, others cause denied service
+for a timed period and others cause the denied service for
+an indefinate period.
+When a client or network is denied access
+for an indefinate period, the only way at present to remove
+the restrictions is by restarting the server.
+.Ss The Kiss-of-Death Packet
+Ordinarily, packets denied service are simply dropped with no
+further action except incrementing statistics counters.
+Sometimes a
+more proactive response is needed, such as a server message that
+explicitly requests the client to stop sending and leave a message
+for the system operator.
+A special packet format has been created
+for this purpose called the "kiss-of-death" (KoD) packet.
+KoD packets have the leap bits set unsynchronized and stratum set
+to zero and the reference identifier field set to a four-byte
+ASCII code.
+If the
+.Cm noserve
+or
+.Cm notrust
+flag of the matching restrict list entry is set,
+the code is "DENY"; if the
+.Cm limited
+flag is set and the rate limit
+is exceeded, the code is "RATE".
+Finally, if a cryptographic violation occurs, the code is "CRYP".
+.Pp
+A client receiving a KoD performs a set of sanity checks to
+minimize security exposure, then updates the stratum and
+reference identifier peer variables, sets the access
+denied (TEST4) bit in the peer flash variable and sends
+a message to the log.
+As long as the TEST4 bit is set,
+the client will send no further packets to the server.
+The only way at present to recover from this condition is
+to restart the protocol at both the client and server.
+This
+happens automatically at the client when the association times out.
+It will happen at the server only if the server operator cooperates.
+.Ss Access Control Commands
+.Bl -tag -width indent
+.It Xo Ic discard
+.Op Cm average Ar avg
+.Op Cm minimum Ar min
+.Op Cm monitor Ar prob
+.Xc
+Set the parameters of the
+.Cm limited
+facility which protects the server from
+client abuse.
+The
+.Cm average
+subcommand specifies the minimum average packet
+spacing, while the
+.Cm minimum
+subcommand specifies the minimum packet spacing.
+Packets that violate these minima are discarded
+and a kiss-o'-death packet returned if enabled.
+The default
+minimum average and minimum are 5 and 2, respectively.
+The monitor subcommand specifies the probability of discard
+for packets that overflow the rate-control window.
+.It Xo Ic restrict address
+.Op Cm mask Ar mask
+.Op Ar flag ...
+.Xc
+The
+.Ar address
+argument expressed in
+dotted-quad form is the address of a host or network.
+Alternatively, the
+.Ar address
+argument can be a valid host DNS name.
+The
+.Ar mask
+argument expressed in dotted-quad form defaults to
+.Cm 255.255.255.255 ,
+meaning that the
+.Ar address
+is treated as the address of an individual host.
+A default entry (address
+.Cm 0.0.0.0 ,
+mask
+.Cm 0.0.0.0 )
+is always included and is always the first entry in the list.
+Note that text string
+.Cm default ,
+with no mask option, may
+be used to indicate the default entry.
+In the current implementation,
+.Cm flag
+always
+restricts access, i.e., an entry with no flags indicates that free
+access to the server is to be given.
+The flags are not orthogonal,
+in that more restrictive flags will often make less restrictive
+ones redundant.
+The flags can generally be classed into two
+categories, those which restrict time service and those which
+restrict informational queries and attempts to do run-time
+reconfiguration of the server.
+One or more of the following flags
+may be specified:
+.Bl -tag -width indent
+.It Cm ignore
+Deny packets of all kinds, including
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+queries.
+.It Cm kod
+If this flag is set when an access violation occurs, a kiss-o'-death
+(KoD) packet is sent.
+KoD packets are rate limited to no more than one
+per second.
+If another KoD packet occurs within one second after the
+last one, the packet is dropped.
+.It Cm limited
+Deny service if the packet spacing violates the lower limits specified
+in the discard command.
+A history of clients is kept using the
+monitoring capability of
+.Xr ntpd @NTPD_MS@ .
+Thus, monitoring is always active as
+long as there is a restriction entry with the
+.Cm limited
+flag.
+.It Cm lowpriotrap
+Declare traps set by matching hosts to be low priority.
+The
+number of traps a server can maintain is limited (the current limit
+is 3).
+Traps are usually assigned on a first come, first served
+basis, with later trap requestors being denied service.
+This flag
+modifies the assignment algorithm by allowing low priority traps to
+be overridden by later requests for normal priority traps.
+.It Cm nomodify
+Deny
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+queries which attempt to modify the state of the
+server (i.e., run time reconfiguration).
+Queries which return
+information are permitted.
+.It Cm noquery
+Deny
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+queries.
+Time service is not affected.
+.It Cm nopeer
+Deny packets which would result in mobilizing a new association.
+This
+includes broadcast and symmetric active packets when a configured
+association does not exist.
+.It Cm noserve
+Deny all packets except
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+queries.
+.It Cm notrap
+Decline to provide mode 6 control message trap service to matching
+hosts.
+The trap service is a subsystem of the ntpdq control message
+protocol which is intended for use by remote event logging programs.
+.It Cm notrust
+Deny service unless the packet is cryptographically authenticated.
+.It Cm ntpport
+This is actually a match algorithm modifier, rather than a
+restriction flag.
+Its presence causes the restriction entry to be
+matched only if the source port in the packet is the standard NTP
+UDP port (123).
+Both
+.Cm ntpport
+and
+.Cm non-ntpport
+may
+be specified.
+The
+.Cm ntpport
+is considered more specific and
+is sorted later in the list.
+.It Cm version
+Deny packets that do not match the current NTP version.
+.El
+.Pp
+Default restriction list entries with the flags ignore, interface,
+ntpport, for each of the local host's interface addresses are
+inserted into the table at startup to prevent the server
+from attempting to synchronize to its own time.
+A default entry is also always present, though if it is
+otherwise unconfigured; no flags are associated
+with the default entry (i.e., everything besides your own
+NTP server is unrestricted).
+.El
+.Sh Automatic NTP Configuration Options
+.Ss Manycasting
+Manycasting is a automatic discovery and configuration paradigm
+new to NTPv4.
+It is intended as a means for a multicast client
+to troll the nearby network neighborhood to find cooperating
+manycast servers, validate them using cryptographic means
+and evaluate their time values with respect to other servers
+that might be lurking in the vicinity.
+The intended result is that each manycast client mobilizes
+client associations with some number of the "best"
+of the nearby manycast servers, yet automatically reconfigures
+to sustain this number of servers should one or another fail.
+.Pp
+Note that the manycasting paradigm does not coincide
+with the anycast paradigm described in RFC-1546,
+which is designed to find a single server from a clique
+of servers providing the same service.
+The manycast paradigm is designed to find a plurality
+of redundant servers satisfying defined optimality criteria.
+.Pp
+Manycasting can be used with either symmetric key
+or public key cryptography.
+The public key infrastructure (PKI)
+offers the best protection against compromised keys
+and is generally considered stronger, at least with relatively
+large key sizes.
+It is implemented using the Autokey protocol and
+the OpenSSL cryptographic library available from
+.Li http://www.openssl.org/ .
+The library can also be used with other NTPv4 modes
+as well and is highly recommended, especially for broadcast modes.
+.Pp
+A persistent manycast client association is configured
+using the manycastclient command, which is similar to the
+server command but with a multicast (IPv4 class
+.Cm D
+or IPv6 prefix
+.Cm FF )
+group address.
+The IANA has designated IPv4 address 224.1.1.1
+and IPv6 address FF05::101 (site local) for NTP.
+When more servers are needed, it broadcasts manycast
+client messages to this address at the minimum feasible rate
+and minimum feasible time-to-live (TTL) hops, depending
+on how many servers have already been found.
+There can be as many manycast client associations
+as different group address, each one serving as a template
+for a future ephemeral unicast client/server association.
+.Pp
+Manycast servers configured with the
+.Ic manycastserver
+command listen on the specified group address for manycast
+client messages.
+Note the distinction between manycast client,
+which actively broadcasts messages, and manycast server,
+which passively responds to them.
+If a manycast server is
+in scope of the current TTL and is itself synchronized
+to a valid source and operating at a stratum level equal
+to or lower than the manycast client, it replies to the
+manycast client message with an ordinary unicast server message.
+.Pp
+The manycast client receiving this message mobilizes
+an ephemeral client/server association according to the
+matching manycast client template, but only if cryptographically
+authenticated and the server stratum is less than or equal
+to the client stratum.
+Authentication is explicitly required
+and either symmetric key or public key (Autokey) can be used.
+Then, the client polls the server at its unicast address
+in burst mode in order to reliably set the host clock
+and validate the source.
+This normally results
+in a volley of eight client/server at 2-s intervals
+during which both the synchronization and cryptographic
+protocols run concurrently.
+Following the volley,
+the client runs the NTP intersection and clustering
+algorithms, which act to discard all but the "best"
+associations according to stratum and synchronization
+distance.
+The surviving associations then continue
+in ordinary client/server mode.
+.Pp
+The manycast client polling strategy is designed to reduce
+as much as possible the volume of manycast client messages
+and the effects of implosion due to near-simultaneous
+arrival of manycast server messages.
+The strategy is determined by the
+.Ic manycastclient ,
+.Ic tos
+and
+.Ic ttl
+configuration commands.
+The manycast poll interval is
+normally eight times the system poll interval,
+which starts out at the
+.Cm minpoll
+value specified in the
+.Ic manycastclient ,
+command and, under normal circumstances, increments to the
+.Cm maxpolll
+value specified in this command.
+Initially, the TTL is
+set at the minimum hops specified by the ttl command.
+At each retransmission the TTL is increased until reaching
+the maximum hops specified by this command or a sufficient
+number client associations have been found.
+Further retransmissions use the same TTL.
+.Pp
+The quality and reliability of the suite of associations
+discovered by the manycast client is determined by the NTP
+mitigation algorithms and the
+.Cm minclock
+and
+.Cm minsane
+values specified in the
+.Ic tos
+configuration command.
+At least
+.Cm minsane
+candidate servers must be available and the mitigation
+algorithms produce at least
+.Cm minclock
+survivors in order to synchronize the clock.
+Byzantine agreement principles require at least four
+candidates in order to correctly discard a single falseticker.
+For legacy purposes,
+.Cm minsane
+defaults to 1 and
+.Cm minclock
+defaults to 3.
+For manycast service
+.Cm minsane
+should be explicitly set to 4, assuming at least that
+number of servers are available.
+.Pp
+If at least
+.Cm minclock
+servers are found, the manycast poll interval is immediately
+set to eight times
+.Cm maxpoll .
+If less than
+.Cm minclock
+servers are found when the TTL has reached the maximum hops,
+the manycast poll interval is doubled.
+For each transmission
+after that, the poll interval is doubled again until
+reaching the maximum of eight times
+.Cm maxpoll .
+Further transmissions use the same poll interval and
+TTL values.
+Note that while all this is going on,
+each client/server association found is operating normally
+it the system poll interval.
+.Pp
+Administratively scoped multicast boundaries are normally
+specified by the network router configuration and,
+in the case of IPv6, the link/site scope prefix.
+By default, the increment for TTL hops is 32 starting
+from 31; however, the
+.Ic ttl
+configuration command can be
+used to modify the values to match the scope rules.
+.Pp
+It is often useful to narrow the range of acceptable
+servers which can be found by manycast client associations.
+Because manycast servers respond only when the client
+stratum is equal to or greater than the server stratum,
+primary (stratum 1) servers fill find only primary servers
+in TTL range, which is probably the most common objective.
+However, unless configured otherwise, all manycast clients
+in TTL range will eventually find all primary servers
+in TTL range, which is probably not the most common
+objective in large networks.
+The
+.Ic tos
+command can be used to modify this behavior.
+Servers with stratum below
+.Cm floor
+or above
+.Cm ceiling
+specified in the
+.Ic tos
+command are strongly discouraged during the selection
+process; however, these servers may be temporally
+accepted if the number of servers within TTL range is
+less than
+.Cm minclock .
+.Pp
+The above actions occur for each manycast client message,
+which repeats at the designated poll interval.
+However, once the ephemeral client association is mobilized,
+subsequent manycast server replies are discarded,
+since that would result in a duplicate association.
+If during a poll interval the number of client associations
+falls below
+.Cm minclock ,
+all manycast client prototype associations are reset
+to the initial poll interval and TTL hops and operation
+resumes from the beginning.
+It is important to avoid
+frequent manycast client messages, since each one requires
+all manycast servers in TTL range to respond.
+The result could well be an implosion, either minor or major,
+depending on the number of servers in range.
+The recommended value for
+.Cm maxpoll
+is 12 (4,096 s).
+.Pp
+It is possible and frequently useful to configure a host
+as both manycast client and manycast server.
+A number of hosts configured this way and sharing a common
+group address will automatically organize themselves
+in an optimum configuration based on stratum and
+synchronization distance.
+For example, consider an NTP
+subnet of two primary servers and a hundred or more
+dependent clients.
+With two exceptions, all servers
+and clients have identical configuration files including both
+.Ic multicastclient
+and
+.Ic multicastserver
+commands using, for instance, multicast group address
+239.1.1.1.
+The only exception is that each primary server
+configuration file must include commands for the primary
+reference source such as a GPS receiver.
+.Pp
+The remaining configuration files for all secondary
+servers and clients have the same contents, except for the
+.Ic tos
+command, which is specific for each stratum level.
+For stratum 1 and stratum 2 servers, that command is
+not necessary.
+For stratum 3 and above servers the
+.Cm floor
+value is set to the intended stratum number.
+Thus, all stratum 3 configuration files are identical,
+all stratum 4 files are identical and so forth.
+.Pp
+Once operations have stabilized in this scenario,
+the primary servers will find the primary reference source
+and each other, since they both operate at the same
+stratum (1), but not with any secondary server or client,
+since these operate at a higher stratum.
+The secondary
+servers will find the servers at the same stratum level.
+If one of the primary servers loses its GPS receiver,
+it will continue to operate as a client and other clients
+will time out the corresponding association and
+re-associate accordingly.
+.Pp
+Some administrators prefer to avoid running
+.Xr ntpd @NTPD_MS@
+continuously and run either
+.Xr ntpdate 8
+or
+.Xr ntpd @NTPD_MS@
+.Fl q
+as a cron job.
+In either case the servers must be
+configured in advance and the program fails if none are
+available when the cron job runs.
+A really slick
+application of manycast is with
+.Xr ntpd @NTPD_MS@
+.Fl q .
+The program wakes up, scans the local landscape looking
+for the usual suspects, selects the best from among
+the rascals, sets the clock and then departs.
+Servers do not have to be configured in advance and
+all clients throughout the network can have the same
+configuration file.
+.Ss Manycast Interactions with Autokey
+Each time a manycast client sends a client mode packet
+to a multicast group address, all manycast servers
+in scope generate a reply including the host name
+and status word.
+The manycast clients then run
+the Autokey protocol, which collects and verifies
+all certificates involved.
+Following the burst interval
+all but three survivors are cast off,
+but the certificates remain in the local cache.
+It often happens that several complete signing trails
+from the client to the primary servers are collected in this way.
+.Pp
+About once an hour or less often if the poll interval
+exceeds this, the client regenerates the Autokey key list.
+This is in general transparent in client/server mode.
+However, about once per day the server private value
+used to generate cookies is refreshed along with all
+manycast client associations.
+In this case all
+cryptographic values including certificates is refreshed.
+If a new certificate has been generated since
+the last refresh epoch, it will automatically revoke
+all prior certificates that happen to be in the
+certificate cache.
+At the same time, the manycast
+scheme starts all over from the beginning and
+the expanding ring shrinks to the minimum and increments
+from there while collecting all servers in scope.
+.Ss Manycast Options
+.Bl -tag -width indent
+.It Xo Ic tos
+.Oo
+.Cm ceiling Ar ceiling |
+.Cm cohort { 0 | 1 } |
+.Cm floor Ar floor |
+.Cm minclock Ar minclock |
+.Cm minsane Ar minsane
+.Oc
+.Xc
+This command affects the clock selection and clustering
+algorithms.
+It can be used to select the quality and
+quantity of peers used to synchronize the system clock
+and is most useful in manycast mode.
+The variables operate
+as follows:
+.Bl -tag -width indent
+.It Cm ceiling Ar ceiling
+Peers with strata above
+.Cm ceiling
+will be discarded if there are at least
+.Cm minclock
+peers remaining.
+This value defaults to 15, but can be changed
+to any number from 1 to 15.
+.It Cm cohort Bro 0 | 1 Brc
+This is a binary flag which enables (0) or disables (1)
+manycast server replies to manycast clients with the same
+stratum level.
+This is useful to reduce implosions where
+large numbers of clients with the same stratum level
+are present.
+The default is to enable these replies.
+.It Cm floor Ar floor
+Peers with strata below
+.Cm floor
+will be discarded if there are at least
+.Cm minclock
+peers remaining.
+This value defaults to 1, but can be changed
+to any number from 1 to 15.
+.It Cm minclock Ar minclock
+The clustering algorithm repeatedly casts out outlyer
+associations until no more than
+.Cm minclock
+associations remain.
+This value defaults to 3,
+but can be changed to any number from 1 to the number of
+configured sources.
+.It Cm minsane Ar minsane
+This is the minimum number of candidates available
+to the clock selection algorithm in order to produce
+one or more truechimers for the clustering algorithm.
+If fewer than this number are available, the clock is
+undisciplined and allowed to run free.
+The default is 1
+for legacy purposes.
+However, according to principles of
+Byzantine agreement,
+.Cm minsane
+should be at least 4 in order to detect and discard
+a single falseticker.
+.El
+.It Cm ttl Ar hop ...
+This command specifies a list of TTL values in increasing
+order, up to 8 values can be specified.
+In manycast mode these values are used in turn
+in an expanding-ring search.
+The default is eight
+multiples of 32 starting at 31.
+.El
+.Sh Reference Clock Support
+The NTP Version 4 daemon supports some three dozen different radio,
+satellite and modem reference clocks plus a special pseudo-clock
+used for backup or when no other clock source is available.
+Detailed descriptions of individual device drivers and options can
+be found in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+Additional information can be found in the pages linked
+there, including the
+.Qq Debugging Hints for Reference Clock Drivers
+and
+.Qq How To Write a Reference Clock Driver
+pages
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+In addition, support for a PPS
+signal is available as described in the
+.Qq Pulse-per-second (PPS) Signal Interfacing
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+Many
+drivers support special line discipline/streams modules which can
+significantly improve the accuracy using the driver.
+These are
+described in the
+.Qq Line Disciplines and Streams Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.Pp
+A reference clock will generally (though not always) be a radio
+timecode receiver which is synchronized to a source of standard
+time such as the services offered by the NRC in Canada and NIST and
+USNO in the US.
+The interface between the computer and the timecode
+receiver is device dependent, but is usually a serial port.
+A
+device driver specific to each reference clock must be selected and
+compiled in the distribution; however, most common radio, satellite
+and modem clocks are included by default.
+Note that an attempt to
+configure a reference clock when the driver has not been compiled
+or the hardware port has not been appropriately configured results
+in a scalding remark to the system log file, but is otherwise non
+hazardous.
+.Pp
+For the purposes of configuration,
+.Xr ntpd @NTPD_MS@
+treats
+reference clocks in a manner analogous to normal NTP peers as much
+as possible.
+Reference clocks are identified by a syntactically
+correct but invalid IP address, in order to distinguish them from
+normal NTP peers.
+Reference clock addresses are of the form
+.Sm off
+.Li 127.127. Ar t . Ar u ,
+.Sm on
+where
+.Ar t
+is an integer
+denoting the clock type and
+.Ar u
+indicates the unit
+number in the range 0-3.
+While it may seem overkill, it is in fact
+sometimes useful to configure multiple reference clocks of the same
+type, in which case the unit numbers must be unique.
+.Pp
+The
+.Ic server
+command is used to configure a reference
+clock, where the
+.Ar address
+argument in that command
+is the clock address.
+The
+.Cm key ,
+.Cm version
+and
+.Cm ttl
+options are not used for reference clock support.
+The
+.Cm mode
+option is added for reference clock support, as
+described below.
+The
+.Cm prefer
+option can be useful to
+persuade the server to cherish a reference clock with somewhat more
+enthusiasm than other reference clocks or peers.
+Further
+information on this option can be found in the
+.Qq Mitigation Rules and the prefer Keyword
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page.
+The
+.Cm minpoll
+and
+.Cm maxpoll
+options have
+meaning only for selected clock drivers.
+See the individual clock
+driver document pages for additional information.
+.Pp
+The
+.Ic fudge
+command is used to provide additional
+information for individual clock drivers and normally follows
+immediately after the
+.Ic server
+command.
+The
+.Ar address
+argument specifies the clock address.
+The
+.Cm refid
+and
+.Cm stratum
+options can be used to
+override the defaults for the device.
+There are two optional
+device-dependent time offsets and four flags that can be included
+in the
+.Ic fudge
+command as well.
+.Pp
+The stratum number of a reference clock is by default zero.
+Since the
+.Xr ntpd @NTPD_MS@
+daemon adds one to the stratum of each
+peer, a primary server ordinarily displays an external stratum of
+one.
+In order to provide engineered backups, it is often useful to
+specify the reference clock stratum as greater than zero.
+The
+.Cm stratum
+option is used for this purpose.
+Also, in cases
+involving both a reference clock and a pulse-per-second (PPS)
+discipline signal, it is useful to specify the reference clock
+identifier as other than the default, depending on the driver.
+The
+.Cm refid
+option is used for this purpose.
+Except where noted,
+these options apply to all clock drivers.
+.Ss Reference Clock Commands
+.Bl -tag -width indent
+.It Xo Ic server
+.Sm off
+.Li 127.127. Ar t . Ar u
+.Sm on
+.Op Cm prefer
+.Op Cm mode Ar int
+.Op Cm minpoll Ar int
+.Op Cm maxpoll Ar int
+.Xc
+This command can be used to configure reference clocks in
+special ways.
+The options are interpreted as follows:
+.Bl -tag -width indent
+.It Cm prefer
+Marks the reference clock as preferred.
+All other things being
+equal, this host will be chosen for synchronization among a set of
+correctly operating hosts.
+See the
+.Qq Mitigation Rules and the prefer Keyword
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+for further information.
+.It Cm mode Ar int
+Specifies a mode number which is interpreted in a
+device-specific fashion.
+For instance, it selects a dialing
+protocol in the ACTS driver and a device subtype in the
+parse
+drivers.
+.It Cm minpoll Ar int
+.It Cm maxpoll Ar int
+These options specify the minimum and maximum polling interval
+for reference clock messages, as a power of 2 in seconds
+For
+most directly connected reference clocks, both
+.Cm minpoll
+and
+.Cm maxpoll
+default to 6 (64 s).
+For modem reference clocks,
+.Cm minpoll
+defaults to 10 (17.1 m) and
+.Cm maxpoll
+defaults to 14 (4.5 h).
+The allowable range is 4 (16 s) to 17 (36.4 h) inclusive.
+.El
+.It Xo Ic fudge
+.Sm off
+.Li 127.127. Ar t . Ar u
+.Sm on
+.Op Cm time1 Ar sec
+.Op Cm time2 Ar sec
+.Op Cm stratum Ar int
+.Op Cm refid Ar string
+.Op Cm mode Ar int
+.Op Cm flag1 Cm 0 \&| Cm 1
+.Op Cm flag2 Cm 0 \&| Cm 1
+.Op Cm flag3 Cm 0 \&| Cm 1
+.Op Cm flag4 Cm 0 \&| Cm 1
+.Xc
+This command can be used to configure reference clocks in
+special ways.
+It must immediately follow the
+.Ic server
+command which configures the driver.
+Note that the same capability
+is possible at run time using the
+.Xr ntpdc @NTPDC_MS@
+program.
+The options are interpreted as
+follows:
+.Bl -tag -width indent
+.It Cm time1 Ar sec
+Specifies a constant to be added to the time offset produced by
+the driver, a fixed-point decimal number in seconds.
+This is used
+as a calibration constant to adjust the nominal time offset of a
+particular clock to agree with an external standard, such as a
+precision PPS signal.
+It also provides a way to correct a
+systematic error or bias due to serial port or operating system
+latencies, different cable lengths or receiver internal delay.
+The
+specified offset is in addition to the propagation delay provided
+by other means, such as internal DIPswitches.
+Where a calibration
+for an individual system and driver is available, an approximate
+correction is noted in the driver documentation pages.
+Note: in order to facilitate calibration when more than one
+radio clock or PPS signal is supported, a special calibration
+feature is available.
+It takes the form of an argument to the
+.Ic enable
+command described in
+.Sx Miscellaneous Options
+page and operates as described in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.It Cm time2 Ar secs
+Specifies a fixed-point decimal number in seconds, which is
+interpreted in a driver-dependent way.
+See the descriptions of
+specific drivers in the
+.Qq Reference Clock Drivers
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+.It Cm stratum Ar int
+Specifies the stratum number assigned to the driver, an integer
+between 0 and 15.
+This number overrides the default stratum number
+ordinarily assigned by the driver itself, usually zero.
+.It Cm refid Ar string
+Specifies an ASCII string of from one to four characters which
+defines the reference identifier used by the driver.
+This string
+overrides the default identifier ordinarily assigned by the driver
+itself.
+.It Cm mode Ar int
+Specifies a mode number which is interpreted in a
+device-specific fashion.
+For instance, it selects a dialing
+protocol in the ACTS driver and a device subtype in the
+parse
+drivers.
+.It Cm flag1 Cm 0 \&| Cm 1
+.It Cm flag2 Cm 0 \&| Cm 1
+.It Cm flag3 Cm 0 \&| Cm 1
+.It Cm flag4 Cm 0 \&| Cm 1
+These four flags are used for customizing the clock driver.
+The
+interpretation of these values, and whether they are used at all,
+is a function of the particular clock driver.
+However, by
+convention
+.Cm flag4
+is used to enable recording monitoring
+data to the
+.Cm clockstats
+file configured with the
+.Ic filegen
+command.
+Further information on the
+.Ic filegen
+command can be found in
+.Sx Monitoring Options .
+.El
+.El
+.Sh Miscellaneous Options
+.Bl -tag -width indent
+.It Ic broadcastdelay Ar seconds
+The broadcast and multicast modes require a special calibration
+to determine the network delay between the local and remote
+servers.
+Ordinarily, this is done automatically by the initial
+protocol exchanges between the client and server.
+In some cases,
+the calibration procedure may fail due to network or server access
+controls, for example.
+This command specifies the default delay to
+be used under these circumstances.
+Typically (for Ethernet), a
+number between 0.003 and 0.007 seconds is appropriate.
+The default
+when this command is not used is 0.004 seconds.
+.It Ic calldelay Ar delay
+This option controls the delay in seconds between the first and second
+packets sent in burst or iburst mode to allow additional time for a modem
+or ISDN call to complete.
+.It Ic driftfile Ar driftfile
+This command specifies the complete path and name of the file used to
+record the frequency of the local clock oscillator.
+This is the same
+operation as the
+.Fl f
+command line option.
+If the file exists, it is read at
+startup in order to set the initial frequency and then updated once per
+hour with the current frequency computed by the daemon.
+If the file name is
+specified, but the file itself does not exist, the starts with an initial
+frequency of zero and creates the file when writing it for the first time.
+If this command is not given, the daemon will always start with an initial
+frequency of zero.
+.Pp
+The file format consists of a single line containing a single
+floating point number, which records the frequency offset measured
+in parts-per-million (PPM).
+The file is updated by first writing
+the current drift value into a temporary file and then renaming
+this file to replace the old version.
+This implies that
+.Xr ntpd @NTPD_MS@
+must have write permission for the directory the
+drift file is located in, and that file system links, symbolic or
+otherwise, should be avoided.
+.It Xo Ic enable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+.It Xo Ic disable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+Provides a way to enable or disable various server options.
+Flags not mentioned are unaffected.
+Note that all of these flags
+can be controlled remotely using the
+.Xr ntpdc @NTPDC_MS@
+utility program.
+.Bl -tag -width indent
+.It Cm auth
+Enables the server to synchronize with unconfigured peers only if the
+peer has been correctly authenticated using either public key or
+private key cryptography.
+The default for this flag is
+.Ic enable .
+.It Cm bclient
+Enables the server to listen for a message from a broadcast or
+multicast server, as in the
+.Ic multicastclient
+command with default
+address.
+The default for this flag is
+.Ic disable .
+.It Cm calibrate
+Enables the calibrate feature for reference clocks.
+The default for
+this flag is
+.Ic disable .
+.It Cm kernel
+Enables the kernel time discipline, if available.
+The default for this
+flag is
+.Ic enable
+if support is available, otherwise
+.Ic disable .
+.It Cm monitor
+Enables the monitoring facility.
+See the
+.Xr ntpdc @NTPDC_MS@
+program
+and the
+.Ic monlist
+command or further information.
+The
+default for this flag is
+.Ic enable .
+.It Cm ntp
+Enables time and frequency discipline.
+In effect, this switch opens and
+closes the feedback loop, which is useful for testing.
+The default for
+this flag is
+.Ic enable .
+.It Cm pps
+Enables the pulse-per-second (PPS) signal when frequency and time is
+disciplined by the precision time kernel modifications.
+See the
+.Qq A Kernel Model for Precision Timekeeping
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page for further information.
+The default for this flag is
+.Ic disable .
+.It Cm stats
+Enables the statistics facility.
+See the
+.Sx Monitoring Options
+section for further information.
+The default for this flag is
+.Ic disable .
+.El
+.It Ic includefile Ar includefile
+This command allows additional configuration commands
+to be included from a separate file.
+Include files may
+be nested to a depth of five; upon reaching the end of any
+include file, command processing resumes in the previous
+configuration file.
+This option is useful for sites that run
+.Xr ntpd @NTPD_MS@
+on multiple hosts, with (mostly) common options (e.g., a
+restriction list).
+.It Ic logconfig Ar configkeyword
+This command controls the amount and type of output written to
+the system
+.Xr syslog 3
+facility or the alternate
+.Ic logfile
+log file.
+By default, all output is turned on.
+All
+.Ar configkeyword
+keywords can be prefixed with
+.Ql = ,
+.Ql +
+and
+.Ql - ,
+where
+.Ql =
+sets the
+.Xr syslog 3
+priority mask,
+.Ql +
+adds and
+.Ql -
+removes
+messages.
+.Xr syslog 3
+messages can be controlled in four
+classes
+.Po
+.Cm clock ,
+.Cm peer ,
+.Cm sys
+and
+.Cm sync
+.Pc .
+Within these classes four types of messages can be
+controlled: informational messages
+.Po
+.Cm info
+.Pc ,
+event messages
+.Po
+.Cm events
+.Pc ,
+statistics messages
+.Po
+.Cm statistics
+.Pc
+and
+status messages
+.Po
+.Cm status
+.Pc .
+.Pp
+Configuration keywords are formed by concatenating the message class with
+the event class.
+The
+.Cm all
+prefix can be used instead of a message class.
+A
+message class may also be followed by the
+.Cm all
+keyword to enable/disable all
+messages of the respective message class.Thus, a minimal log configuration
+could look like this:
+.Bd -literal
+logconfig =syncstatus +sysevents
+.Ed
+.Pp
+This would just list the synchronizations state of
+.Xr ntpd @NTPD_MS@
+and the major system events.
+For a simple reference server, the
+following minimum message configuration could be useful:
+.Bd -literal
+logconfig =syncall +clockall
+.Ed
+.Pp
+This configuration will list all clock information and
+synchronization information.
+All other events and messages about
+peers, system events and so on is suppressed.
+.It Ic logfile Ar logfile
+This command specifies the location of an alternate log file to
+be used instead of the default system
+.Xr syslog 3
+facility.
+This is the same operation as the -l command line option.
+.It Ic setvar Ar variable Op Cm default
+This command adds an additional system variable.
+These
+variables can be used to distribute additional information such as
+the access policy.
+If the variable of the form
+.Sm off
+.Va name = Ar value
+.Sm on
+is followed by the
+.Cm default
+keyword, the
+variable will be listed as part of the default system variables
+.Po
+.Xr ntpq @NTPQ_MS@
+.Ic rv
+command
+.Pc ) .
+These additional variables serve
+informational purposes only.
+They are not related to the protocol
+other that they can be listed.
+The known protocol variables will
+always override any variables defined via the
+.Ic setvar
+mechanism.
+There are three special variables that contain the names
+of all variable of the same group.
+The
+.Va sys_var_list
+holds
+the names of all system variables.
+The
+.Va peer_var_list
+holds
+the names of all peer variables and the
+.Va clock_var_list
+holds the names of the reference clock variables.
+.It Xo Ic tinker
+.Oo
+.Cm allan Ar allan |
+.Cm dispersion Ar dispersion |
+.Cm freq Ar freq |
+.Cm huffpuff Ar huffpuff |
+.Cm panic Ar panic |
+.Cm step Ar srep |
+.Cm stepout Ar stepout
+.Oc
+.Xc
+This command can be used to alter several system variables in
+very exceptional circumstances.
+It should occur in the
+configuration file before any other configuration options.
+The
+default values of these variables have been carefully optimized for
+a wide range of network speeds and reliability expectations.
+In
+general, they interact in intricate ways that are hard to predict
+and some combinations can result in some very nasty behavior.
+Very
+rarely is it necessary to change the default values; but, some
+folks cannot resist twisting the knobs anyway and this command is
+for them.
+Emphasis added: twisters are on their own and can expect
+no help from the support group.
+.Pp
+The variables operate as follows:
+.Bl -tag -width indent
+.It Cm allan Ar allan
+The argument becomes the new value for the minimum Allan
+intercept, which is a parameter of the PLL/FLL clock discipline
+algorithm.
+The value in log2 seconds defaults to 7 (1024 s), which is also the lower
+limit.
+.It Cm dispersion Ar dispersion
+The argument becomes the new value for the dispersion increase rate,
+normally .000015 s/s.
+.It Cm freq Ar freq
+The argument becomes the initial value of the frequency offset in
+parts-per-million.
+This overrides the value in the frequency file, if
+present, and avoids the initial training state if it is not.
+.It Cm huffpuff Ar huffpuff
+The argument becomes the new value for the experimental
+huff-n'-puff filter span, which determines the most recent interval
+the algorithm will search for a minimum delay.
+The lower limit is
+900 s (15 m), but a more reasonable value is 7200 (2 hours).
+There
+is no default, since the filter is not enabled unless this command
+is given.
+.It Cm panic Ar panic
+The argument is the panic threshold, normally 1000 s.
+If set to zero,
+the panic sanity check is disabled and a clock offset of any value will
+be accepted.
+.It Cm step Ar step
+The argument is the step threshold, which by default is 0.128 s.
+It can
+be set to any positive number in seconds.
+If set to zero, step
+adjustments will never occur.
+Note: The kernel time discipline is
+disabled if the step threshold is set to zero or greater than the
+default.
+.It Cm stepout Ar stepout
+The argument is the stepout timeout, which by default is 900 s.
+It can
+be set to any positive number in seconds.
+If set to zero, the stepout
+pulses will not be suppressed.
+.El
+.It Xo Ic trap Ar host_address
+.Op Cm port Ar port_number
+.Op Cm interface Ar interface_address
+.Xc
+This command configures a trap receiver at the given host
+address and port number for sending messages with the specified
+local interface address.
+If the port number is unspecified, a value
+of 18447 is used.
+If the interface address is not specified, the
+message is sent with a source address of the local interface the
+message is sent through.
+Note that on a multihomed host the
+interface used may vary from time to time with routing changes.
+.Pp
+The trap receiver will generally log event messages and other
+information from the server in a log file.
+While such monitor
+programs may also request their own trap dynamically, configuring a
+trap receiver will ensure that no messages are lost when the server
+is started.
+.It Cm hop Ar ...
+This command specifies a list of TTL values in increasing order, up to 8
+values can be specified.
+In manycast mode these values are used in turn in
+an expanding-ring search.
+The default is eight multiples of 32 starting at
+31.
+.El
.Sh FILES
+.Bl -tag -width /etc/ntp.drift -compact
+.It Pa /etc/ntp.conf
+the default name of the configuration file
+.It Pa ntp.keys
+private MD5 keys
+.It Pa ntpkey
+RSA private key
+.It Pa ntpkey_ Ns Ar host
+RSA public key
+.It Pa ntp_dh
+Diffie-Hellman agreement parameters
+.El
.Sh "SEE ALSO"
+.Sh SEE ALSO
+.Xr ntpd @NTPD_MS@ ,
+.Xr ntpdc @NTPDC_MS@ ,
+.Xr ntpq @NTPQ_MS@
+.Pp
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+.Li http://www.ntp.org/ .
+A snapshot of this documentation is available in HTML format in
+.Pa /usr/share/doc/ntp .
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 4)
+.%O RFC5905
+.Re
.Sh "AUTHORS"
The University of Delaware
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The syntax checking is not picky; some combinations of
+ridiculous and even hilarious options and modes may not be
+detected.
+.Pp
+The
+.Pa ntpkey_ Ns Ar host
+files are really digital
+certificates.
+These should be obtained via secure directory
+services when they become universally available.Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntp.conf\fP
option definitions.
-.TH ntp.keys 5man "01 Jan 2013" "4.2.7p343" "File Formats"
+.TH ntp.keys 5man "03 Jan 2013" "4.2.7p344" "File Formats"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntp.man)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:33:45 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:15 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp.keys.def
.\" and the template file agman-file.tpl
.\"
.PP
.PP
.SH DESCRIPTION
+This document describes the format of an NTP symmetric key file.
+For a description of the use of this type of file, see the
+.Qq Authentication Support
+section of the
+.Xr ntp.conf 5
+page.
+.PP
+.Xr ntpd 8
+reads its keys from a file specified using the
+k
+command line option or the
+.Ic keys
+statement in the configuration file.
+While key number 0 is fixed by the NTP standard
+(as 56 zero bits)
+and may not be changed,
+one or more keys numbered between 1 and 65534
+may be arbitrarily set in the keys file.
+.PP
+The key file uses the same comment conventions
+as the configuration file.
+Key entries use a fixed format of the form
+.PP
+.D1 Ar keyno type key
+.PP
+where
+\fIkeyno\fR
+is a positive integer (between 1 and 65534),
+\fItype\fR
+is the message digest algorithm,
+and
+\fIkey\fR
+is the key itself.
+.PP
+The
+\fIkey\fR
+may be given in a format
+controlled by the
+\fItype\fR
+field.
+The
+\fItype\fR
+.Li MD5
+is always supported.
+If
+.Li ntpd
+was built with the OpenSSL library
+then any digest library supported by that library may be specified.
+However, if compliance with FIPS 140-2 is required the
+\fItype\fR
+must be either
+.Li SHA
+or
+.Li SHA1 .
+.PP
+What follows are some key types, and corresponding formats:
+.PP
+.TP
+.BR Li MD5
+The key is 1 to 16 printable characters terminated by
+an EOL,
+whitespace,
+or
+a
+.Li #
+(which is the "start of comment" character).
+.PP
+.TP
+.BR Li SHA
+.TP
+.BR Li SHA1
+.TP
+.BR Li RMD160
+The key is a hex-encoded ASCII string of 40 characters,
+which is truncated as necessary.
+.PP
+Note that the keys used by the
+.Xr ntpq 8
+and
+.Xr ntpdc 8
+programs are checked against passwords
+requested by the programs and entered by hand,
+so it is generally appropriate to specify these keys in ASCII format.
.SH FILES
+.TP
+.BR Pa /etc/ntp.keys
+the default name of the configuration file
.SH "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpd 1ntpdmdoc ,
+.Xr ntpdate 1ntpdatemdoc ,
+.Xr ntpdc 1ntpdcmdoc ,
+.Xr sntp 1sntpmdoc
.SH "AUTHORS"
The University of Delaware
.SH "COPYRIGHT"
.SH "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntp.keys\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTP_KEYS 5mdoc File Formats
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntp.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:19:46 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:33 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp.keys.def
.\" and the template file agmdoc-file.tpl
.Sh NAME
.Sy /etc/ntp.keys
.Pp
.Sh DESCRIPTION
+This document describes the format of an NTP symmetric key file.
+For a description of the use of this type of file, see the
+.Qq Authentication Support
+section of the
+.Xr ntp.conf 5
+page.
+.Pp
+.Xr ntpd 8
+reads its keys from a file specified using the
+.Fl k
+command line option or the
+.Ic keys
+statement in the configuration file.
+While key number 0 is fixed by the NTP standard
+(as 56 zero bits)
+and may not be changed,
+one or more keys numbered between 1 and 65534
+may be arbitrarily set in the keys file.
+.Pp
+The key file uses the same comment conventions
+as the configuration file.
+Key entries use a fixed format of the form
+.Pp
+.D1 Ar keyno type key
+.Pp
+where
+.Ar keyno
+is a positive integer (between 1 and 65534),
+.Ar type
+is the message digest algorithm,
+and
+.Ar key
+is the key itself.
+.Pp
+The
+.Ar key
+may be given in a format
+controlled by the
+.Ar type
+field.
+The
+.Ar type
+.Li MD5
+is always supported.
+If
+.Li ntpd
+was built with the OpenSSL library
+then any digest library supported by that library may be specified.
+However, if compliance with FIPS 140-2 is required the
+.Ar type
+must be either
+.Li SHA
+or
+.Li SHA1 .
+.Pp
+What follows are some key types, and corresponding formats:
+.Pp
+.Bl -tag -width RMD160 -compact
+.It Li MD5
+The key is 1 to 16 printable characters terminated by
+an EOL,
+whitespace,
+or
+a
+.Li #
+(which is the "start of comment" character).
+.Pp
+.It Li SHA
+.It Li SHA1
+.It Li RMD160
+The key is a hex-encoded ASCII string of 40 characters,
+which is truncated as necessary.
+.El
+.Pp
+Note that the keys used by the
+.Xr ntpq 8
+and
+.Xr ntpdc 8
+programs are checked against passwords
+requested by the programs and entered by hand,
+so it is generally appropriate to specify these keys in ASCII format.
.Sh FILES
+.Bl -tag -width /etc/ntp.keys -compact
+.It Pa /etc/ntp.keys
+the default name of the configuration file
+.El
.Sh "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpd 1ntpdmdoc ,
+.Xr ntpdate 1ntpdatemdoc ,
+.Xr ntpdc 1ntpdcmdoc ,
+.Xr sntp 1sntpmdoc
.Sh "AUTHORS"
The University of Delaware
.Sh "COPYRIGHT"
.Sh "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntp.keys\fP
option definitions.
<p>This document describes the symmetric key file for the NTP Project's
<code>ntpd</code> program.
- <p>This document applies to version 4.2.7p343 of <code>ntp.keys</code>.
+ <p>This document applies to version 4.2.7p344 of <code>ntp.keys</code>.
<div class="shortcontents">
<h2>Short Contents</h2>
-.TH ntp.keys 5 "01 Jan 2013" "4.2.7p343" "File Formats"
+.TH ntp.keys 5 "03 Jan 2013" "4.2.7p344" "File Formats"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntp.man)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:33:45 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:15 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp.keys.def
.\" and the template file agman-file.tpl
.\"
.PP
.PP
.SH DESCRIPTION
+This document describes the format of an NTP symmetric key file.
+For a description of the use of this type of file, see the
+.Qq Authentication Support
+section of the
+.Xr ntp.conf 5
+page.
+.PP
+.Xr ntpd 8
+reads its keys from a file specified using the
+k
+command line option or the
+.Ic keys
+statement in the configuration file.
+While key number 0 is fixed by the NTP standard
+(as 56 zero bits)
+and may not be changed,
+one or more keys numbered between 1 and 65534
+may be arbitrarily set in the keys file.
+.PP
+The key file uses the same comment conventions
+as the configuration file.
+Key entries use a fixed format of the form
+.PP
+.D1 Ar keyno type key
+.PP
+where
+\fIkeyno\fR
+is a positive integer (between 1 and 65534),
+\fItype\fR
+is the message digest algorithm,
+and
+\fIkey\fR
+is the key itself.
+.PP
+The
+\fIkey\fR
+may be given in a format
+controlled by the
+\fItype\fR
+field.
+The
+\fItype\fR
+.Li MD5
+is always supported.
+If
+.Li ntpd
+was built with the OpenSSL library
+then any digest library supported by that library may be specified.
+However, if compliance with FIPS 140-2 is required the
+\fItype\fR
+must be either
+.Li SHA
+or
+.Li SHA1 .
+.PP
+What follows are some key types, and corresponding formats:
+.PP
+.TP
+.BR Li MD5
+The key is 1 to 16 printable characters terminated by
+an EOL,
+whitespace,
+or
+a
+.Li #
+(which is the "start of comment" character).
+.PP
+.TP
+.BR Li SHA
+.TP
+.BR Li SHA1
+.TP
+.BR Li RMD160
+The key is a hex-encoded ASCII string of 40 characters,
+which is truncated as necessary.
+.PP
+Note that the keys used by the
+.Xr ntpq 8
+and
+.Xr ntpdc 8
+programs are checked against passwords
+requested by the programs and entered by hand,
+so it is generally appropriate to specify these keys in ASCII format.
.SH FILES
+.TP
+.BR Pa /etc/ntp.keys
+the default name of the configuration file
.SH "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpd @NTPD_MS@ ,
+.Xr ntpdate @NTPDATE_MS@ ,
+.Xr ntpdc @NTPDC_MS@ ,
+.Xr sntp @SNTP_MS@
.SH "AUTHORS"
The University of Delaware
.SH "COPYRIGHT"
.SH "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntp.keys\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTP_KEYS 5 File Formats
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntp.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:19:46 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:33 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp.keys.def
.\" and the template file agmdoc-file.tpl
.Sh NAME
.Sy /etc/ntp.keys
.Pp
.Sh DESCRIPTION
+This document describes the format of an NTP symmetric key file.
+For a description of the use of this type of file, see the
+.Qq Authentication Support
+section of the
+.Xr ntp.conf 5
+page.
+.Pp
+.Xr ntpd 8
+reads its keys from a file specified using the
+.Fl k
+command line option or the
+.Ic keys
+statement in the configuration file.
+While key number 0 is fixed by the NTP standard
+(as 56 zero bits)
+and may not be changed,
+one or more keys numbered between 1 and 65534
+may be arbitrarily set in the keys file.
+.Pp
+The key file uses the same comment conventions
+as the configuration file.
+Key entries use a fixed format of the form
+.Pp
+.D1 Ar keyno type key
+.Pp
+where
+.Ar keyno
+is a positive integer (between 1 and 65534),
+.Ar type
+is the message digest algorithm,
+and
+.Ar key
+is the key itself.
+.Pp
+The
+.Ar key
+may be given in a format
+controlled by the
+.Ar type
+field.
+The
+.Ar type
+.Li MD5
+is always supported.
+If
+.Li ntpd
+was built with the OpenSSL library
+then any digest library supported by that library may be specified.
+However, if compliance with FIPS 140-2 is required the
+.Ar type
+must be either
+.Li SHA
+or
+.Li SHA1 .
+.Pp
+What follows are some key types, and corresponding formats:
+.Pp
+.Bl -tag -width RMD160 -compact
+.It Li MD5
+The key is 1 to 16 printable characters terminated by
+an EOL,
+whitespace,
+or
+a
+.Li #
+(which is the "start of comment" character).
+.Pp
+.It Li SHA
+.It Li SHA1
+.It Li RMD160
+The key is a hex-encoded ASCII string of 40 characters,
+which is truncated as necessary.
+.El
+.Pp
+Note that the keys used by the
+.Xr ntpq 8
+and
+.Xr ntpdc 8
+programs are checked against passwords
+requested by the programs and entered by hand,
+so it is generally appropriate to specify these keys in ASCII format.
.Sh FILES
+.Bl -tag -width /etc/ntp.keys -compact
+.It Pa /etc/ntp.keys
+the default name of the configuration file
+.El
.Sh "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpd @NTPD_MS@ ,
+.Xr ntpdate @NTPDATE_MS@ ,
+.Xr ntpdc @NTPDC_MS@ ,
+.Xr sntp @SNTP_MS@
.Sh "AUTHORS"
The University of Delaware
.Sh "COPYRIGHT"
.Sh "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
+This document was derived from FreeBSD.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntp.keys\fP
option definitions.
/*
* EDIT THIS FILE WITH CAUTION (ntpd-opts.c)
*
- * It has been AutoGen-ed January 1, 2013 at 11:32:54 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:07:05 PM by AutoGen 5.17.1pre11
* From the definitions ntpd-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This source file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* ntpd option static const strings
*/
static char const ntpd_opt_strs[2987] =
-/* 0 */ "ntpd 4.2.7p343\n"
+/* 0 */ "ntpd 4.2.7p344\n"
"Copyright (C) 1970-2013 The University of Delaware, all rights reserved.\n"
"This is free software. It is licensed for use, modification and\n"
"redistribution under the terms of the NTP License, copies of which\n"
/* 2753 */ "Output version information and exit\0"
/* 2789 */ "version\0"
/* 2797 */ "NTPD\0"
-/* 2802 */ "ntpd - NTP daemon program - Ver. 4.2.7p343\n"
+/* 2802 */ "ntpd - NTP daemon program - Ver. 4.2.7p344\n"
"USAGE: %s [ -<flag> [<val>] | --<name>[{=| }<val>] ]... \\\n"
"\t\t[ <server1> ... <serverN> ]\n\0"
/* 2935 */ "http://bugs.ntp.org, bugs@ntp.org\0"
/* 2969 */ "\n\n\0"
-/* 2972 */ "ntpd 4.2.7p343";
+/* 2972 */ "ntpd 4.2.7p344";
/*
* ipv4 option description with
#define zExplain (ntpd_opt_strs+2969)
#define zDetail (NULL)
#define zFullVersion (ntpd_opt_strs+2972)
-/* extracted from optcode.tlib near line 350 */
+/* extracted from optcode.tlib near line 353 */
#if defined(ENABLE_NLS)
# define OPTPROC_BASE OPTPROC_TRANSLATE
static void
doOptDebug_Level(tOptions* pOptions, tOptDesc* pOptDesc)
{
+ /*
+ * Be sure the flag-code[0] handles special values for the options pointer
+ * viz. (poptions <= OPTPROC_EMIT_LIMIT) *and also* the special flag bit
+ * ((poptdesc->fOptState & OPTST_RESET) != 0) telling the option to
+ * reset its state.
+ */
/* extracted from debug-opt.def, line 15 */
OPT_VALUE_SET_DEBUG_LEVEL++;
(void)pOptDesc;
(void)pOptions;
}
#endif /* defined(TEST_NTPD_OPTS) */
-/* extracted from optmain.tlib near line 48 */
+/* extracted from optmain.tlib near line 46 */
#if defined(TEST_NTPD_OPTS) /* TEST MAIN PROCEDURE: */
return res;
}
#endif /* defined TEST_NTPD_OPTS */
-/* extracted from optmain.tlib near line 1146 */
+/* extracted from optmain.tlib near line 1188 */
/**
* The directory containing the data associated with ntpd.
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#ifdef HAVE_DCGETTEXT
+# include <gettext.h>
+#endif
#include <autoopts/usage-txt.h>
-static char* AO_gettext(char const* pz);
-static void coerce_it(void** s);
+static char * AO_gettext(char const * pz);
+static void coerce_it(void ** s);
/**
- * AutoGen specific wrapper function for gettext.
- * It relies on the macro _() to convert from English to the target
- * language, then strdup-duplicates the result string.
+ * AutoGen specific wrapper function for gettext. It relies on the macro _()
+ * to convert from English to the target language, then strdup-duplicates the
+ * result string. It tries the "libopts" domain first, then whatever has been
+ * set via the \a textdomain(3) call.
*
* @param[in] pz the input text used as a lookup key.
* @returns the translated text (if there is one),
* or the original text (if not).
*/
static char *
-AO_gettext(char const* pz)
+AO_gettext(char const * pz)
{
- char* pzRes;
+ char * res;
if (pz == NULL)
return NULL;
- pzRes = _(pz);
- if (pzRes == pz)
- return pzRes;
- pzRes = strdup(pzRes);
- if (pzRes == NULL) {
+#ifdef HAVE_DCGETTEXT
+ /*
+ * While processing the option_xlateable_txt data, try to use the
+ * "libopts" domain. Once we switch to the option descriptor data,
+ * do *not* use that domain.
+ */
+ if (option_xlateable_txt.field_ct != 0) {
+ res = dgettext("libopts", pz);
+ if (res == pz)
+ res = (char *)(void *)_(pz);
+ } else
+ res = (char *)(void *)_(pz);
+#else
+ res = (char *)(void *)_(pz);
+#endif
+ if (res == pz)
+ return res;
+ res = strdup(res);
+ if (res == NULL) {
fputs(_("No memory for duping translated strings\n"), stderr);
exit(NTPD_EXIT_FAILURE);
}
- return pzRes;
+ return res;
}
-static void coerce_it(void** s) { *s = AO_gettext(*s);
+/**
+ * All the pointers we use are marked "* const", but they are stored in
+ * writable memory. Coerce the mutability and set the pointer.
+ */
+static void coerce_it(void ** s) { *s = AO_gettext(*s);
}
/**
static void
translate_option_strings(void)
{
- tOptions * const pOpt = &ntpdOptions;
+ tOptions * const opts = &ntpdOptions;
/*
* Guard against re-translation. It won't work. The strings will have
* been changed by the first pass through this code. One shot only.
*/
- if (option_usage_text.field_ct != 0) {
+ if (option_xlateable_txt.field_ct != 0) {
/*
* Do the translations. The first pointer follows the field count
* field. The field count field is the size of a pointer.
*/
- tOptDesc * pOD = pOpt->pOptDesc;
- char ** ppz = (char**)(void*)&(option_usage_text);
- int ix = option_usage_text.field_ct;
+ tOptDesc * od = opts->pOptDesc;
+ char ** ppz = (char**)(void*)&(option_xlateable_txt);
+ int ix = option_xlateable_txt.field_ct;
do {
- ppz++;
+ ppz++; /* skip over field_ct */
*ppz = AO_gettext(*ppz);
} while (--ix > 0);
-
- coerce_it((void*)&(pOpt->pzCopyright));
- coerce_it((void*)&(pOpt->pzCopyNotice));
- coerce_it((void*)&(pOpt->pzFullVersion));
- coerce_it((void*)&(pOpt->pzUsageTitle));
- coerce_it((void*)&(pOpt->pzExplain));
- coerce_it((void*)&(pOpt->pzDetail));
- coerce_it((void*)&(pOpt->pzPackager));
- option_usage_text.field_ct = 0;
-
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++)
- coerce_it((void*)&(pOD->pzText));
+ /* prevent re-translation and disable "libopts" domain lookup */
+ option_xlateable_txt.field_ct = 0;
+
+ coerce_it((void*)&(opts->pzCopyright));
+ coerce_it((void*)&(opts->pzCopyNotice));
+ coerce_it((void*)&(opts->pzFullVersion));
+ coerce_it((void*)&(opts->pzUsageTitle));
+ coerce_it((void*)&(opts->pzExplain));
+ coerce_it((void*)&(opts->pzDetail));
+ coerce_it((void*)&(opts->pzPackager));
+
+ for (ix = opts->optCt; ix > 0; ix--, od++)
+ coerce_it((void*)&(od->pzText));
}
- if ((pOpt->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
- tOptDesc * pOD = pOpt->pOptDesc;
+ if ((opts->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
+ tOptDesc * od = opts->pOptDesc;
int ix;
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++) {
- coerce_it((void*)&(pOD->pz_Name));
- coerce_it((void*)&(pOD->pz_DisableName));
- coerce_it((void*)&(pOD->pz_DisablePfx));
+ for (ix = opts->optCt; ix > 0; ix--, od++) {
+ coerce_it((void*)&(od->pz_Name));
+ coerce_it((void*)&(od->pz_DisableName));
+ coerce_it((void*)&(od->pz_DisablePfx));
}
- /* prevent re-translation */
ntpdOptions.fOptSet |= OPTPROC_NXLAT_OPT_CFG | OPTPROC_NXLAT_OPT;
}
}
/*
* EDIT THIS FILE WITH CAUTION (ntpd-opts.h)
*
- * It has been AutoGen-ed January 1, 2013 at 11:32:53 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:07:03 PM by AutoGen 5.17.1pre11
* From the definitions ntpd-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This header file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* tolerable version is at least as old as what was current when the header
* template was released.
*/
-#define AO_TEMPLATE_VERSION 147461
+#define AO_TEMPLATE_VERSION 151552
#if (AO_TEMPLATE_VERSION < OPTIONS_MINIMUM_VERSION) \
|| (AO_TEMPLATE_VERSION > OPTIONS_STRUCT_VERSION)
# error option template version mismatches autoopts/options.h header
} teOptIndex;
#define OPTION_CT 37
-#define NTPD_VERSION "4.2.7p343"
-#define NTPD_FULL_VERSION "ntpd 4.2.7p343"
+#define NTPD_VERSION "4.2.7p344"
+#define NTPD_FULL_VERSION "ntpd 4.2.7p344"
/*
* Interface defines for all options. Replace "n" with the UPPER_CASED
* Enumeration of ntpd exit codes
*/
typedef enum {
- NTPD_EXIT_SUCCESS = 0,
- NTPD_EXIT_FAILURE = 1,
- NTPD_EXIT_LIBOPTS_FAILURE = 70
+ NTPD_EXIT_SUCCESS = 0,
+ NTPD_EXIT_FAILURE = 1,
+ NTPD_EXIT_USAGE_ERROR = 64,
+ NTPD_EXIT_LIBOPTS_FAILURE = 70
} ntpd_exit_code_t;
/*
* Make sure there are no #define name conflicts with the option names
ntpdOptions.pzCurOpt = NULL)
#define START_OPT RESTART_OPT(1)
#define USAGE(c) (*ntpdOptions.pUsageProc)(&ntpdOptions, c)
-/* extracted from opthead.tlib near line 484 */
+/* extracted from opthead.tlib near line 497 */
#ifdef __cplusplus
extern "C" {
-.TH ntpd 1ntpdman "01 Jan 2013" "4.2.7p343" "User Commands"
+.TH ntpd 1ntpdman "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntpd-opts.man)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:33:48 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:18 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpd-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntpd
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..." [ <server1> ... <serverN> ]
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..." " " "[ <server1> ... <serverN> ]"
.PP
.SH DESCRIPTION
+The
+.B
+utility is an operating system daemon which sets
+and maintains the system time of day in synchronism with Internet
+standard time servers.
+It is a complete implementation of the
+Network Time Protocol (NTP) version 4, as defined by RFC-5905,
+but also retains compatibility with
+version 3, as defined by RFC-1305, and versions 1
+and 2, as defined by RFC-1059 and RFC-1119, respectively.
+.PP
+The
+.B
+utility does most computations in 64-bit floating point
+arithmetic and does relatively clumsy 64-bit fixed point operations
+only when necessary to preserve the ultimate precision, about 232
+picoseconds.
+While the ultimate precision is not achievable with
+ordinary workstations and networks of today, it may be required
+with future gigahertz CPU clocks and gigabit LANs.
+.PP
+Ordinarily,
+.B
+reads the
+.Xr ntp.conf 5
+configuration file at startup time in order to determine the
+synchronization sources and operating modes.
+It is also possible to
+specify a working, although limited, configuration entirely on the
+command line, obviating the need for a configuration file.
+This may
+be particularly useful when the local host is to be configured as a
+broadcast/multicast client, with all peers being determined by
+listening to broadcasts at run time.
+.PP
+If NetInfo support is built into
+.B ,
+then
+.B
+will attempt to read its configuration from the
+NetInfo if the default
+.Xr ntp.conf 5
+file cannot be read and no file is
+specified by the
+c
+option.
+.PP
+Various internal
+.B
+variables can be displayed and
+configuration options altered while the
+.B
+is running
+using the
+.Xr ntpq 8
+and
+.Xr ntpdc 8
+utility programs.
+.PP
+When
+.B
+starts it looks at the value of
+.Xr umask 2 ,
+and if zero
+.B
+will set the
+.Xr umask 2
+to 022.
.SH "OPTIONS"
.TP
.BR \-4 ", " -\-ipv4
.fi
.ad
.SH USAGE
+.SS "How NTP Operates"
+The
+.B
+utility operates by exchanging messages with
+one or more configured servers over a range of designated poll intervals.
+When
+started, whether for the first or subsequent times, the program
+requires several exchanges from the majority of these servers so
+the signal processing and mitigation algorithms can accumulate and
+groom the data and set the clock.
+In order to protect the network
+from bursts, the initial poll interval for each server is delayed
+an interval randomized over a few seconds.
+At the default initial poll
+interval of 64s, several minutes can elapse before the clock is
+set.
+This initial delay to set the clock
+can be safely and dramatically reduced using the
+.Cm iburst
+keyword with the
+.Ic server
+configuration
+command, as described in
+.Xr ntp.conf 5 .
+.PP
+Most operating systems and hardware of today incorporate a
+time-of-year (TOY) chip to maintain the time during periods when
+the power is off.
+When the machine is booted, the chip is used to
+initialize the operating system time.
+After the machine has
+synchronized to a NTP server, the operating system corrects the
+chip from time to time.
+In the default case, if
+.B
+detects that the time on the host
+is more than 1000s from the server time,
+.B
+assumes something must be terribly wrong and the only
+reliable action is for the operator to intervene and set the clock
+by hand.
+(Reasons for this include there is no TOY chip,
+or its battery is dead, or that the TOY chip is just of poor quality.)
+This causes
+.B
+to exit with a panic message to
+the system log.
+The
+g
+option overrides this check and the
+clock will be set to the server time regardless of the chip time
+(up to 68 years in the past or future \(em
+this is a limitation of the NTPv4 protocol).
+However, and to protect against broken hardware, such as when the
+CMOS battery fails or the clock counter becomes defective, once the
+clock has been set an error greater than 1000s will cause
+.B
+to exit anyway.
+.PP
+Under ordinary conditions,
+.B
+adjusts the clock in
+small steps so that the timescale is effectively continuous and
+without discontinuities.
+Under conditions of extreme network
+congestion, the roundtrip delay jitter can exceed three seconds and
+the synchronization distance, which is equal to one-half the
+roundtrip delay plus error budget terms, can become very large.
+The
+.B
+algorithms discard sample offsets exceeding 128 ms,
+unless the interval during which no sample offset is less than 128
+ms exceeds 900s.
+The first sample after that, no matter what the
+offset, steps the clock to the indicated time.
+In practice this
+reduces the false alarm rate where the clock is stepped in error to
+a vanishingly low incidence.
+.PP
+As the result of this behavior, once the clock has been set it
+very rarely strays more than 128 ms even under extreme cases of
+network path congestion and jitter.
+Sometimes, in particular when
+.B
+is first started without a valid drift file
+on a system with a large intrinsic drift
+the error might grow to exceed 128 ms,
+which would cause the clock to be set backwards
+if the local clock time is more than 128 s
+in the future relative to the server.
+In some applications, this behavior may be unacceptable.
+There are several solutions, however.
+If the
+x
+option is included on the command line, the clock will
+never be stepped and only slew corrections will be used.
+But this choice comes with a cost that
+should be carefully explored before deciding to use
+the
+x
+option.
+The maximum slew rate possible is limited
+to 500 parts-per-million (PPM) as a consequence of the correctness
+principles on which the NTP protocol and algorithm design are
+based.
+As a result, the local clock can take a long time to
+converge to an acceptable offset, about 2,000 s for each second the
+clock is outside the acceptable range.
+During this interval the
+local clock will not be consistent with any other network clock and
+the system cannot be used for distributed applications that require
+correctly synchronized network time.
+.PP
+In spite of the above precautions, sometimes when large
+frequency errors are present the resulting time offsets stray
+outside the 128-ms range and an eventual step or slew time
+correction is required.
+If following such a correction the
+frequency error is so large that the first sample is outside the
+acceptable range,
+.B
+enters the same state as when the
+.Pa ntp.drift
+file is not present.
+The intent of this behavior
+is to quickly correct the frequency and restore operation to the
+normal tracking mode.
+In the most extreme cases
+(the host
+.Cm time.ien.it
+comes to mind), there may be occasional
+step/slew corrections and subsequent frequency corrections.
+It
+helps in these cases to use the
+.Cm burst
+keyword when
+configuring the server, but
+ONLY
+when you have permission to do so from the owner of the target host.
+.PP
+Finally,
+in the past many startup scripts would run
+.Xr ntpdate 8
+to get the system clock close to correct before starting
+.Xr ntpd 8 ,
+but this was never more than a mediocre hack and is no longer needed.
+.PP
+There is a way to start
+.Xr ntpd 8
+that often addresses all of the problems mentioned above.
+.SS "Starting NTP (Best Current Practice)"
+First, use the
+.Cm iburst
+option on your
+.Cm server
+entries.
+.PP
+If you can also keep a good
+.Pa ntp.drift
+file then
+.Xr ntpd 8
+will effectively "warm-start" and your system's clock will
+be stable in under 11 seconds' time.
+.PP
+As soon as possible in the startup sequence, start
+.Xr ntpd 8
+with at least the
+g
+and perhaps the
+N
+options.
+Then,
+start the rest of your "normal" processes.
+This will give
+.Xr ntpd 8
+as much time as possible to get the system's clock synchronized and stable.
+.PP
+Finally,
+if you have processes like
+.Cm dovecot
+or database servers
+that require
+monotonically-increasing time,
+run
+.Xr ntp-wait 8
+as late as possible in the boot sequence
+(perhaps with the
+v
+flag)
+and after
+.Xr ntp-wait 8
+exits successfully
+it is as safe as it will ever be to start any process that require
+stable time.
+.SS "Frequency Discipline"
+The
+.B
+behavior at startup depends on whether the
+frequency file, usually
+.Pa ntp.drift ,
+exists.
+This file
+contains the latest estimate of clock frequency error.
+When the
+.B
+is started and the file does not exist, the
+.B
+enters a special mode designed to quickly adapt to
+the particular system clock oscillator time and frequency error.
+This takes approximately 15 minutes, after which the time and
+frequency are set to nominal values and the
+.B
+enters
+normal mode, where the time and frequency are continuously tracked
+relative to the server.
+After one hour the frequency file is
+created and the current frequency offset written to it.
+When the
+.B
+is started and the file does exist, the
+.B
+frequency is initialized from the file and enters normal mode
+immediately.
+After that the current frequency offset is written to
+the file at hourly intervals.
+.SS "Operating Modes"
+The
+.B
+utility can operate in any of several modes, including
+symmetric active/passive, client/server broadcast/multicast and
+manycast, as described in the
+.Qq Association Management
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+It normally operates continuously while
+monitoring for small changes in frequency and trimming the clock
+for the ultimate precision.
+However, it can operate in a one-time
+mode where the time is set from an external server and frequency is
+set from a previously recorded frequency file.
+A
+broadcast/multicast or manycast client can discover remote servers,
+compute server-client propagation delay correction factors and
+configure itself automatically.
+This makes it possible to deploy a
+fleet of workstations without specifying configuration details
+specific to the local environment.
+.PP
+By default,
+.B
+runs in continuous mode where each of
+possibly several external servers is polled at intervals determined
+by an intricate state machine.
+The state machine measures the
+incidental roundtrip delay jitter and oscillator frequency wander
+and determines the best poll interval using a heuristic algorithm.
+Ordinarily, and in most operating environments, the state machine
+will start with 64s intervals and eventually increase in steps to
+1024s.
+A small amount of random variation is introduced in order to
+avoid bunching at the servers.
+In addition, should a server become
+unreachable for some time, the poll interval is increased in steps
+to 1024s in order to reduce network overhead.
+.PP
+In some cases it may not be practical for
+.B
+to run
+continuously.
+A common workaround has been to run the
+.Xr ntpdate 8
+program from a
+.Xr cron 8
+job at designated
+times.
+However, this program does not have the crafted signal
+processing, error checking and mitigation algorithms of
+.B .
+The
+q
+option is intended for this purpose.
+Setting this option will cause
+.B
+to exit just after
+setting the clock for the first time.
+The procedure for initially
+setting the clock is the same as in continuous mode; most
+applications will probably want to specify the
+.Cm iburst
+keyword with the
+.Ic server
+configuration command.
+With this
+keyword a volley of messages are exchanged to groom the data and
+the clock is set in about 10 s.
+If nothing is heard after a
+couple of minutes, the daemon times out and exits.
+After a suitable
+period of mourning, the
+.Xr ntpdate 8
+program may be
+retired.
+.PP
+When kernel support is available to discipline the clock
+frequency, which is the case for stock Solaris, Tru64, Linux and
+.Fx ,
+a useful feature is available to discipline the clock
+frequency.
+First,
+.B
+is run in continuous mode with
+selected servers in order to measure and record the intrinsic clock
+frequency offset in the frequency file.
+It may take some hours for
+the frequency and offset to settle down.
+Then the
+.B
+is
+stopped and run in one-time mode as required.
+At each startup, the
+frequency is read from the file and initializes the kernel
+frequency.
+.SS "Poll Interval Control"
+This version of NTP includes an intricate state machine to
+reduce the network load while maintaining a quality of
+synchronization consistent with the observed jitter and wander.
+There are a number of ways to tailor the operation in order enhance
+accuracy by reducing the interval or to reduce network overhead by
+increasing it.
+However, the user is advised to carefully consider
+the consequences of changing the poll adjustment range from the
+default minimum of 64 s to the default maximum of 1,024 s.
+The
+default minimum can be changed with the
+.Ic tinker
+.Cm minpoll
+command to a value not less than 16 s.
+This value is used for all
+configured associations, unless overridden by the
+.Cm minpoll
+option on the configuration command.
+Note that most device drivers
+will not operate properly if the poll interval is less than 64 s
+and that the broadcast server and manycast client associations will
+also use the default, unless overridden.
+.PP
+In some cases involving dial up or toll services, it may be
+useful to increase the minimum interval to a few tens of minutes
+and maximum interval to a day or so.
+Under normal operation
+conditions, once the clock discipline loop has stabilized the
+interval will be increased in steps from the minimum to the
+maximum.
+However, this assumes the intrinsic clock frequency error
+is small enough for the discipline loop correct it.
+The capture
+range of the loop is 500 PPM at an interval of 64s decreasing by a
+factor of two for each doubling of interval.
+At a minimum of 1,024
+s, for example, the capture range is only 31 PPM.
+If the intrinsic
+error is greater than this, the drift file
+.Pa ntp.drift
+will
+have to be specially tailored to reduce the residual error below
+this limit.
+Once this is done, the drift file is automatically
+updated once per hour and is available to initialize the frequency
+on subsequent daemon restarts.
+.SS "The huff-n'-puff Filter"
+In scenarios where a considerable amount of data are to be
+downloaded or uploaded over telephone modems, timekeeping quality
+can be seriously degraded.
+This occurs because the differential
+delays on the two directions of transmission can be quite large.
+In
+many cases the apparent time errors are so large as to exceed the
+step threshold and a step correction can occur during and after the
+data transfer is in progress.
+.PP
+The huff-n'-puff filter is designed to correct the apparent time
+offset in these cases.
+It depends on knowledge of the propagation
+delay when no other traffic is present.
+In common scenarios this
+occurs during other than work hours.
+The filter maintains a shift
+register that remembers the minimum delay over the most recent
+interval measured usually in hours.
+Under conditions of severe
+delay, the filter corrects the apparent offset using the sign of
+the offset and the difference between the apparent delay and
+minimum delay.
+The name of the filter reflects the negative (huff)
+and positive (puff) correction, which depends on the sign of the
+offset.
+.PP
+The filter is activated by the
+.Ic tinker
+command and
+.Cm huffpuff
+keyword, as described in
+.Xr ntp.conf 5 .
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH FILES
+.TP
+.BR Pa /etc/ntp.conf
+the default name of the configuration file
+.TP
+.BR Pa /etc/ntp.drift
+the default name of the drift file
+.TP
+.BR Pa /etc/ntp.keys
+the default name of the key file
.SH "EXIT STATUS"
One of the following exit values will be returned:
.TP
.BR 1 " (EXIT_FAILURE)"
The operation failed or the command syntax was not valid.
.SH "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpdate 8 ,
+.Xr ntpdc 8 ,
+.Xr ntpq 8
+.PP
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+.Li http://www.ntp.org/ .
+A snapshot of this documentation is available in HTML format in
+.Pa /usr/share/doc/ntp .
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 1)
+.%O RFC1059
+.Re
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 2)
+.%O RFC1119
+.Re
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 3)
+.%O RFC1305
+.Re
+.Rs
+.%A David L. Mills
+.%A J. Martin, Ed.
+.%A J. Burbank
+.%A W. Kasch
+.%T Network Time Protocol Version 4: Protocol and Algorithms Specification
+.%O RFC5905
+.Re
+.Rs
+.%A David L. Mills
+.%A B. Haberman, Ed.
+.%T Network Time Protocol Version 4: Autokey Specification
+.%O RFC5906
+.Re
+.Rs
+.%A H. Gerstung
+.%A C. Elliott
+.%A B. Haberman, Ed.
+.%T Definitions of Managed Objects for Network Time Protocol Version 4: (NTPv4)
+.%O RFC5907
+.Re
+.Rs
+.%A R. Gayraud
+.%A B. Lourdelet
+.%T Network Time Protocol (NTP) Server Option for DHCPv6
+.%O RFC5908
+.Re
.SH "AUTHORS"
The University of Delaware
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The
+.B
+utility has gotten rather fat.
+While not huge, it has gotten
+larger than might be desirable for an elevated-priority
+.B
+running on a workstation, particularly since many of
+the fancy features which consume the space were designed more with
+a busy primary server, rather than a high stratum workstation in
+mind.Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
+Portions of this document came from FreeBSD.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntpd\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTPD 1ntpdmdoc User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntpd-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:19:48 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:34 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpd-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
[ <server1> ... <serverN> ]
.Pp
.Sh DESCRIPTION
+The
+.Nm
+utility is an operating system daemon which sets
+and maintains the system time of day in synchronism with Internet
+standard time servers.
+It is a complete implementation of the
+Network Time Protocol (NTP) version 4, as defined by RFC-5905,
+but also retains compatibility with
+version 3, as defined by RFC-1305, and versions 1
+and 2, as defined by RFC-1059 and RFC-1119, respectively.
+.Pp
+The
+.Nm
+utility does most computations in 64-bit floating point
+arithmetic and does relatively clumsy 64-bit fixed point operations
+only when necessary to preserve the ultimate precision, about 232
+picoseconds.
+While the ultimate precision is not achievable with
+ordinary workstations and networks of today, it may be required
+with future gigahertz CPU clocks and gigabit LANs.
+.Pp
+Ordinarily,
+.Nm
+reads the
+.Xr ntp.conf 5
+configuration file at startup time in order to determine the
+synchronization sources and operating modes.
+It is also possible to
+specify a working, although limited, configuration entirely on the
+command line, obviating the need for a configuration file.
+This may
+be particularly useful when the local host is to be configured as a
+broadcast/multicast client, with all peers being determined by
+listening to broadcasts at run time.
+.Pp
+If NetInfo support is built into
+.Nm ,
+then
+.Nm
+will attempt to read its configuration from the
+NetInfo if the default
+.Xr ntp.conf 5
+file cannot be read and no file is
+specified by the
+.Fl c
+option.
+.Pp
+Various internal
+.Nm
+variables can be displayed and
+configuration options altered while the
+.Nm
+is running
+using the
+.Xr ntpq 8
+and
+.Xr ntpdc 8
+utility programs.
+.Pp
+When
+.Nm
+starts it looks at the value of
+.Xr umask 2 ,
+and if zero
+.Nm
+will set the
+.Xr umask 2
+to 022.
.Sh "OPTIONS"
.Bl -tag
.It \-4 ", " -\-ipv4
.fi
.ad
.Sh USAGE
+.Ss "How NTP Operates"
+The
+.Nm
+utility operates by exchanging messages with
+one or more configured servers over a range of designated poll intervals.
+When
+started, whether for the first or subsequent times, the program
+requires several exchanges from the majority of these servers so
+the signal processing and mitigation algorithms can accumulate and
+groom the data and set the clock.
+In order to protect the network
+from bursts, the initial poll interval for each server is delayed
+an interval randomized over a few seconds.
+At the default initial poll
+interval of 64s, several minutes can elapse before the clock is
+set.
+This initial delay to set the clock
+can be safely and dramatically reduced using the
+.Cm iburst
+keyword with the
+.Ic server
+configuration
+command, as described in
+.Xr ntp.conf 5 .
+.Pp
+Most operating systems and hardware of today incorporate a
+time-of-year (TOY) chip to maintain the time during periods when
+the power is off.
+When the machine is booted, the chip is used to
+initialize the operating system time.
+After the machine has
+synchronized to a NTP server, the operating system corrects the
+chip from time to time.
+In the default case, if
+.Nm
+detects that the time on the host
+is more than 1000s from the server time,
+.Nm
+assumes something must be terribly wrong and the only
+reliable action is for the operator to intervene and set the clock
+by hand.
+(Reasons for this include there is no TOY chip,
+or its battery is dead, or that the TOY chip is just of poor quality.)
+This causes
+.Nm
+to exit with a panic message to
+the system log.
+The
+.Fl g
+option overrides this check and the
+clock will be set to the server time regardless of the chip time
+(up to 68 years in the past or future \(em
+this is a limitation of the NTPv4 protocol).
+However, and to protect against broken hardware, such as when the
+CMOS battery fails or the clock counter becomes defective, once the
+clock has been set an error greater than 1000s will cause
+.Nm
+to exit anyway.
+.Pp
+Under ordinary conditions,
+.Nm
+adjusts the clock in
+small steps so that the timescale is effectively continuous and
+without discontinuities.
+Under conditions of extreme network
+congestion, the roundtrip delay jitter can exceed three seconds and
+the synchronization distance, which is equal to one-half the
+roundtrip delay plus error budget terms, can become very large.
+The
+.Nm
+algorithms discard sample offsets exceeding 128 ms,
+unless the interval during which no sample offset is less than 128
+ms exceeds 900s.
+The first sample after that, no matter what the
+offset, steps the clock to the indicated time.
+In practice this
+reduces the false alarm rate where the clock is stepped in error to
+a vanishingly low incidence.
+.Pp
+As the result of this behavior, once the clock has been set it
+very rarely strays more than 128 ms even under extreme cases of
+network path congestion and jitter.
+Sometimes, in particular when
+.Nm
+is first started without a valid drift file
+on a system with a large intrinsic drift
+the error might grow to exceed 128 ms,
+which would cause the clock to be set backwards
+if the local clock time is more than 128 s
+in the future relative to the server.
+In some applications, this behavior may be unacceptable.
+There are several solutions, however.
+If the
+.Fl x
+option is included on the command line, the clock will
+never be stepped and only slew corrections will be used.
+But this choice comes with a cost that
+should be carefully explored before deciding to use
+the
+.Fl x
+option.
+The maximum slew rate possible is limited
+to 500 parts-per-million (PPM) as a consequence of the correctness
+principles on which the NTP protocol and algorithm design are
+based.
+As a result, the local clock can take a long time to
+converge to an acceptable offset, about 2,000 s for each second the
+clock is outside the acceptable range.
+During this interval the
+local clock will not be consistent with any other network clock and
+the system cannot be used for distributed applications that require
+correctly synchronized network time.
+.Pp
+In spite of the above precautions, sometimes when large
+frequency errors are present the resulting time offsets stray
+outside the 128-ms range and an eventual step or slew time
+correction is required.
+If following such a correction the
+frequency error is so large that the first sample is outside the
+acceptable range,
+.Nm
+enters the same state as when the
+.Pa ntp.drift
+file is not present.
+The intent of this behavior
+is to quickly correct the frequency and restore operation to the
+normal tracking mode.
+In the most extreme cases
+(the host
+.Cm time.ien.it
+comes to mind), there may be occasional
+step/slew corrections and subsequent frequency corrections.
+It
+helps in these cases to use the
+.Cm burst
+keyword when
+configuring the server, but
+ONLY
+when you have permission to do so from the owner of the target host.
+.Pp
+Finally,
+in the past many startup scripts would run
+.Xr ntpdate 8
+to get the system clock close to correct before starting
+.Xr ntpd 8 ,
+but this was never more than a mediocre hack and is no longer needed.
+.Pp
+There is a way to start
+.Xr ntpd 8
+that often addresses all of the problems mentioned above.
+.Ss "Starting NTP (Best Current Practice)"
+First, use the
+.Cm iburst
+option on your
+.Cm server
+entries.
+.Pp
+If you can also keep a good
+.Pa ntp.drift
+file then
+.Xr ntpd 8
+will effectively "warm-start" and your system's clock will
+be stable in under 11 seconds' time.
+.Pp
+As soon as possible in the startup sequence, start
+.Xr ntpd 8
+with at least the
+.Fl g
+and perhaps the
+.Fl N
+options.
+Then,
+start the rest of your "normal" processes.
+This will give
+.Xr ntpd 8
+as much time as possible to get the system's clock synchronized and stable.
+.Pp
+Finally,
+if you have processes like
+.Cm dovecot
+or database servers
+that require
+monotonically-increasing time,
+run
+.Xr ntp-wait 8
+as late as possible in the boot sequence
+(perhaps with the
+.Fl v
+flag)
+and after
+.Xr ntp-wait 8
+exits successfully
+it is as safe as it will ever be to start any process that require
+stable time.
+.Ss "Frequency Discipline"
+The
+.Nm
+behavior at startup depends on whether the
+frequency file, usually
+.Pa ntp.drift ,
+exists.
+This file
+contains the latest estimate of clock frequency error.
+When the
+.Nm
+is started and the file does not exist, the
+.Nm
+enters a special mode designed to quickly adapt to
+the particular system clock oscillator time and frequency error.
+This takes approximately 15 minutes, after which the time and
+frequency are set to nominal values and the
+.Nm
+enters
+normal mode, where the time and frequency are continuously tracked
+relative to the server.
+After one hour the frequency file is
+created and the current frequency offset written to it.
+When the
+.Nm
+is started and the file does exist, the
+.Nm
+frequency is initialized from the file and enters normal mode
+immediately.
+After that the current frequency offset is written to
+the file at hourly intervals.
+.Ss "Operating Modes"
+The
+.Nm
+utility can operate in any of several modes, including
+symmetric active/passive, client/server broadcast/multicast and
+manycast, as described in the
+.Qq Association Management
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+It normally operates continuously while
+monitoring for small changes in frequency and trimming the clock
+for the ultimate precision.
+However, it can operate in a one-time
+mode where the time is set from an external server and frequency is
+set from a previously recorded frequency file.
+A
+broadcast/multicast or manycast client can discover remote servers,
+compute server-client propagation delay correction factors and
+configure itself automatically.
+This makes it possible to deploy a
+fleet of workstations without specifying configuration details
+specific to the local environment.
+.Pp
+By default,
+.Nm
+runs in continuous mode where each of
+possibly several external servers is polled at intervals determined
+by an intricate state machine.
+The state machine measures the
+incidental roundtrip delay jitter and oscillator frequency wander
+and determines the best poll interval using a heuristic algorithm.
+Ordinarily, and in most operating environments, the state machine
+will start with 64s intervals and eventually increase in steps to
+1024s.
+A small amount of random variation is introduced in order to
+avoid bunching at the servers.
+In addition, should a server become
+unreachable for some time, the poll interval is increased in steps
+to 1024s in order to reduce network overhead.
+.Pp
+In some cases it may not be practical for
+.Nm
+to run
+continuously.
+A common workaround has been to run the
+.Xr ntpdate 8
+program from a
+.Xr cron 8
+job at designated
+times.
+However, this program does not have the crafted signal
+processing, error checking and mitigation algorithms of
+.Nm .
+The
+.Fl q
+option is intended for this purpose.
+Setting this option will cause
+.Nm
+to exit just after
+setting the clock for the first time.
+The procedure for initially
+setting the clock is the same as in continuous mode; most
+applications will probably want to specify the
+.Cm iburst
+keyword with the
+.Ic server
+configuration command.
+With this
+keyword a volley of messages are exchanged to groom the data and
+the clock is set in about 10 s.
+If nothing is heard after a
+couple of minutes, the daemon times out and exits.
+After a suitable
+period of mourning, the
+.Xr ntpdate 8
+program may be
+retired.
+.Pp
+When kernel support is available to discipline the clock
+frequency, which is the case for stock Solaris, Tru64, Linux and
+.Fx ,
+a useful feature is available to discipline the clock
+frequency.
+First,
+.Nm
+is run in continuous mode with
+selected servers in order to measure and record the intrinsic clock
+frequency offset in the frequency file.
+It may take some hours for
+the frequency and offset to settle down.
+Then the
+.Nm
+is
+stopped and run in one-time mode as required.
+At each startup, the
+frequency is read from the file and initializes the kernel
+frequency.
+.Ss "Poll Interval Control"
+This version of NTP includes an intricate state machine to
+reduce the network load while maintaining a quality of
+synchronization consistent with the observed jitter and wander.
+There are a number of ways to tailor the operation in order enhance
+accuracy by reducing the interval or to reduce network overhead by
+increasing it.
+However, the user is advised to carefully consider
+the consequences of changing the poll adjustment range from the
+default minimum of 64 s to the default maximum of 1,024 s.
+The
+default minimum can be changed with the
+.Ic tinker
+.Cm minpoll
+command to a value not less than 16 s.
+This value is used for all
+configured associations, unless overridden by the
+.Cm minpoll
+option on the configuration command.
+Note that most device drivers
+will not operate properly if the poll interval is less than 64 s
+and that the broadcast server and manycast client associations will
+also use the default, unless overridden.
+.Pp
+In some cases involving dial up or toll services, it may be
+useful to increase the minimum interval to a few tens of minutes
+and maximum interval to a day or so.
+Under normal operation
+conditions, once the clock discipline loop has stabilized the
+interval will be increased in steps from the minimum to the
+maximum.
+However, this assumes the intrinsic clock frequency error
+is small enough for the discipline loop correct it.
+The capture
+range of the loop is 500 PPM at an interval of 64s decreasing by a
+factor of two for each doubling of interval.
+At a minimum of 1,024
+s, for example, the capture range is only 31 PPM.
+If the intrinsic
+error is greater than this, the drift file
+.Pa ntp.drift
+will
+have to be specially tailored to reduce the residual error below
+this limit.
+Once this is done, the drift file is automatically
+updated once per hour and is available to initialize the frequency
+on subsequent daemon restarts.
+.Ss "The huff-n'-puff Filter"
+In scenarios where a considerable amount of data are to be
+downloaded or uploaded over telephone modems, timekeeping quality
+can be seriously degraded.
+This occurs because the differential
+delays on the two directions of transmission can be quite large.
+In
+many cases the apparent time errors are so large as to exceed the
+step threshold and a step correction can occur during and after the
+data transfer is in progress.
+.Pp
+The huff-n'-puff filter is designed to correct the apparent time
+offset in these cases.
+It depends on knowledge of the propagation
+delay when no other traffic is present.
+In common scenarios this
+occurs during other than work hours.
+The filter maintains a shift
+register that remembers the minimum delay over the most recent
+interval measured usually in hours.
+Under conditions of severe
+delay, the filter corrects the apparent offset using the sign of
+the offset and the difference between the apparent delay and
+minimum delay.
+The name of the filter reflects the negative (huff)
+and positive (puff) correction, which depends on the sign of the
+offset.
+.Pp
+The filter is activated by the
+.Ic tinker
+command and
+.Cm huffpuff
+keyword, as described in
+.Xr ntp.conf 5 .
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh FILES
+.Bl -tag -width /etc/ntp.drift -compact
+.It Pa /etc/ntp.conf
+the default name of the configuration file
+.It Pa /etc/ntp.drift
+the default name of the drift file
+.It Pa /etc/ntp.keys
+the default name of the key file
+.El
.Sh "EXIT STATUS"
One of the following exit values will be returned:
.Bl -tag
The operation failed or the command syntax was not valid.
.El
.Sh "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpdate 8 ,
+.Xr ntpdc 8 ,
+.Xr ntpq 8
+.Pp
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+.Li http://www.ntp.org/ .
+A snapshot of this documentation is available in HTML format in
+.Pa /usr/share/doc/ntp .
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 1)
+.%O RFC1059
+.Re
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 2)
+.%O RFC1119
+.Re
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 3)
+.%O RFC1305
+.Re
+.Rs
+.%A David L. Mills
+.%A J. Martin, Ed.
+.%A J. Burbank
+.%A W. Kasch
+.%T Network Time Protocol Version 4: Protocol and Algorithms Specification
+.%O RFC5905
+.Re
+.Rs
+.%A David L. Mills
+.%A B. Haberman, Ed.
+.%T Network Time Protocol Version 4: Autokey Specification
+.%O RFC5906
+.Re
+.Rs
+.%A H. Gerstung
+.%A C. Elliott
+.%A B. Haberman, Ed.
+.%T Definitions of Managed Objects for Network Time Protocol Version 4: (NTPv4)
+.%O RFC5907
+.Re
+.Rs
+.%A R. Gayraud
+.%A B. Lourdelet
+.%T Network Time Protocol (NTP) Server Option for DHCPv6
+.%O RFC5908
+.Re
.Sh "AUTHORS"
The University of Delaware
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The
+.Nm
+utility has gotten rather fat.
+While not huge, it has gotten
+larger than might be desirable for an elevated-priority
+.Nm
+running on a workstation, particularly since many of
+the fancy features which consume the space were designed more with
+a busy primary server, rather than a high stratum workstation in
+mind.Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
+Portions of this document came from FreeBSD.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntpd\fP
option definitions.
symmetric and broadcast modes, and with both symmetric-key and public-key
cryptography.
- <p>This document applies to version 4.2.7p343 of <code>ntpd</code>.
+ <p>This document applies to version 4.2.7p344 of <code>ntpd</code>.
<ul class="menu">
<li><a accesskey="1" href="#ntpd-Description">ntpd Description</a>: Description
used to select the program, defaulting to <span class="file">more</span>. Both will exit
with a status code of 0.
-<pre class="example">ntpd - NTP daemon program - Ver. 4.2.7p342
+<pre class="example">ntpd - NTP daemon program - Ver. 4.2.7p343
USAGE: ntpd [ -<flag> [<val>] | --<name>[{=| }<val>] ]... \
[ <server1> ... <serverN> ]
Flg Arg Option-Name Description
-.TH ntpd @NTPD_MS@ "01 Jan 2013" "4.2.7p343" "User Commands"
+.TH ntpd @NTPD_MS@ "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntpd-opts.man)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:33:48 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:18 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpd-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntpd
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..." [ <server1> ... <serverN> ]
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..." " " "[ <server1> ... <serverN> ]"
.PP
.SH DESCRIPTION
+The
+.B
+utility is an operating system daemon which sets
+and maintains the system time of day in synchronism with Internet
+standard time servers.
+It is a complete implementation of the
+Network Time Protocol (NTP) version 4, as defined by RFC-5905,
+but also retains compatibility with
+version 3, as defined by RFC-1305, and versions 1
+and 2, as defined by RFC-1059 and RFC-1119, respectively.
+.PP
+The
+.B
+utility does most computations in 64-bit floating point
+arithmetic and does relatively clumsy 64-bit fixed point operations
+only when necessary to preserve the ultimate precision, about 232
+picoseconds.
+While the ultimate precision is not achievable with
+ordinary workstations and networks of today, it may be required
+with future gigahertz CPU clocks and gigabit LANs.
+.PP
+Ordinarily,
+.B
+reads the
+.Xr ntp.conf 5
+configuration file at startup time in order to determine the
+synchronization sources and operating modes.
+It is also possible to
+specify a working, although limited, configuration entirely on the
+command line, obviating the need for a configuration file.
+This may
+be particularly useful when the local host is to be configured as a
+broadcast/multicast client, with all peers being determined by
+listening to broadcasts at run time.
+.PP
+If NetInfo support is built into
+.B ,
+then
+.B
+will attempt to read its configuration from the
+NetInfo if the default
+.Xr ntp.conf 5
+file cannot be read and no file is
+specified by the
+c
+option.
+.PP
+Various internal
+.B
+variables can be displayed and
+configuration options altered while the
+.B
+is running
+using the
+.Xr ntpq 8
+and
+.Xr ntpdc 8
+utility programs.
+.PP
+When
+.B
+starts it looks at the value of
+.Xr umask 2 ,
+and if zero
+.B
+will set the
+.Xr umask 2
+to 022.
.SH "OPTIONS"
.TP
.BR \-4 ", " -\-ipv4
.fi
.ad
.SH USAGE
+.SS "How NTP Operates"
+The
+.B
+utility operates by exchanging messages with
+one or more configured servers over a range of designated poll intervals.
+When
+started, whether for the first or subsequent times, the program
+requires several exchanges from the majority of these servers so
+the signal processing and mitigation algorithms can accumulate and
+groom the data and set the clock.
+In order to protect the network
+from bursts, the initial poll interval for each server is delayed
+an interval randomized over a few seconds.
+At the default initial poll
+interval of 64s, several minutes can elapse before the clock is
+set.
+This initial delay to set the clock
+can be safely and dramatically reduced using the
+.Cm iburst
+keyword with the
+.Ic server
+configuration
+command, as described in
+.Xr ntp.conf 5 .
+.PP
+Most operating systems and hardware of today incorporate a
+time-of-year (TOY) chip to maintain the time during periods when
+the power is off.
+When the machine is booted, the chip is used to
+initialize the operating system time.
+After the machine has
+synchronized to a NTP server, the operating system corrects the
+chip from time to time.
+In the default case, if
+.B
+detects that the time on the host
+is more than 1000s from the server time,
+.B
+assumes something must be terribly wrong and the only
+reliable action is for the operator to intervene and set the clock
+by hand.
+(Reasons for this include there is no TOY chip,
+or its battery is dead, or that the TOY chip is just of poor quality.)
+This causes
+.B
+to exit with a panic message to
+the system log.
+The
+g
+option overrides this check and the
+clock will be set to the server time regardless of the chip time
+(up to 68 years in the past or future \(em
+this is a limitation of the NTPv4 protocol).
+However, and to protect against broken hardware, such as when the
+CMOS battery fails or the clock counter becomes defective, once the
+clock has been set an error greater than 1000s will cause
+.B
+to exit anyway.
+.PP
+Under ordinary conditions,
+.B
+adjusts the clock in
+small steps so that the timescale is effectively continuous and
+without discontinuities.
+Under conditions of extreme network
+congestion, the roundtrip delay jitter can exceed three seconds and
+the synchronization distance, which is equal to one-half the
+roundtrip delay plus error budget terms, can become very large.
+The
+.B
+algorithms discard sample offsets exceeding 128 ms,
+unless the interval during which no sample offset is less than 128
+ms exceeds 900s.
+The first sample after that, no matter what the
+offset, steps the clock to the indicated time.
+In practice this
+reduces the false alarm rate where the clock is stepped in error to
+a vanishingly low incidence.
+.PP
+As the result of this behavior, once the clock has been set it
+very rarely strays more than 128 ms even under extreme cases of
+network path congestion and jitter.
+Sometimes, in particular when
+.B
+is first started without a valid drift file
+on a system with a large intrinsic drift
+the error might grow to exceed 128 ms,
+which would cause the clock to be set backwards
+if the local clock time is more than 128 s
+in the future relative to the server.
+In some applications, this behavior may be unacceptable.
+There are several solutions, however.
+If the
+x
+option is included on the command line, the clock will
+never be stepped and only slew corrections will be used.
+But this choice comes with a cost that
+should be carefully explored before deciding to use
+the
+x
+option.
+The maximum slew rate possible is limited
+to 500 parts-per-million (PPM) as a consequence of the correctness
+principles on which the NTP protocol and algorithm design are
+based.
+As a result, the local clock can take a long time to
+converge to an acceptable offset, about 2,000 s for each second the
+clock is outside the acceptable range.
+During this interval the
+local clock will not be consistent with any other network clock and
+the system cannot be used for distributed applications that require
+correctly synchronized network time.
+.PP
+In spite of the above precautions, sometimes when large
+frequency errors are present the resulting time offsets stray
+outside the 128-ms range and an eventual step or slew time
+correction is required.
+If following such a correction the
+frequency error is so large that the first sample is outside the
+acceptable range,
+.B
+enters the same state as when the
+.Pa ntp.drift
+file is not present.
+The intent of this behavior
+is to quickly correct the frequency and restore operation to the
+normal tracking mode.
+In the most extreme cases
+(the host
+.Cm time.ien.it
+comes to mind), there may be occasional
+step/slew corrections and subsequent frequency corrections.
+It
+helps in these cases to use the
+.Cm burst
+keyword when
+configuring the server, but
+ONLY
+when you have permission to do so from the owner of the target host.
+.PP
+Finally,
+in the past many startup scripts would run
+.Xr ntpdate 8
+to get the system clock close to correct before starting
+.Xr ntpd 8 ,
+but this was never more than a mediocre hack and is no longer needed.
+.PP
+There is a way to start
+.Xr ntpd 8
+that often addresses all of the problems mentioned above.
+.SS "Starting NTP (Best Current Practice)"
+First, use the
+.Cm iburst
+option on your
+.Cm server
+entries.
+.PP
+If you can also keep a good
+.Pa ntp.drift
+file then
+.Xr ntpd 8
+will effectively "warm-start" and your system's clock will
+be stable in under 11 seconds' time.
+.PP
+As soon as possible in the startup sequence, start
+.Xr ntpd 8
+with at least the
+g
+and perhaps the
+N
+options.
+Then,
+start the rest of your "normal" processes.
+This will give
+.Xr ntpd 8
+as much time as possible to get the system's clock synchronized and stable.
+.PP
+Finally,
+if you have processes like
+.Cm dovecot
+or database servers
+that require
+monotonically-increasing time,
+run
+.Xr ntp-wait 8
+as late as possible in the boot sequence
+(perhaps with the
+v
+flag)
+and after
+.Xr ntp-wait 8
+exits successfully
+it is as safe as it will ever be to start any process that require
+stable time.
+.SS "Frequency Discipline"
+The
+.B
+behavior at startup depends on whether the
+frequency file, usually
+.Pa ntp.drift ,
+exists.
+This file
+contains the latest estimate of clock frequency error.
+When the
+.B
+is started and the file does not exist, the
+.B
+enters a special mode designed to quickly adapt to
+the particular system clock oscillator time and frequency error.
+This takes approximately 15 minutes, after which the time and
+frequency are set to nominal values and the
+.B
+enters
+normal mode, where the time and frequency are continuously tracked
+relative to the server.
+After one hour the frequency file is
+created and the current frequency offset written to it.
+When the
+.B
+is started and the file does exist, the
+.B
+frequency is initialized from the file and enters normal mode
+immediately.
+After that the current frequency offset is written to
+the file at hourly intervals.
+.SS "Operating Modes"
+The
+.B
+utility can operate in any of several modes, including
+symmetric active/passive, client/server broadcast/multicast and
+manycast, as described in the
+.Qq Association Management
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+It normally operates continuously while
+monitoring for small changes in frequency and trimming the clock
+for the ultimate precision.
+However, it can operate in a one-time
+mode where the time is set from an external server and frequency is
+set from a previously recorded frequency file.
+A
+broadcast/multicast or manycast client can discover remote servers,
+compute server-client propagation delay correction factors and
+configure itself automatically.
+This makes it possible to deploy a
+fleet of workstations without specifying configuration details
+specific to the local environment.
+.PP
+By default,
+.B
+runs in continuous mode where each of
+possibly several external servers is polled at intervals determined
+by an intricate state machine.
+The state machine measures the
+incidental roundtrip delay jitter and oscillator frequency wander
+and determines the best poll interval using a heuristic algorithm.
+Ordinarily, and in most operating environments, the state machine
+will start with 64s intervals and eventually increase in steps to
+1024s.
+A small amount of random variation is introduced in order to
+avoid bunching at the servers.
+In addition, should a server become
+unreachable for some time, the poll interval is increased in steps
+to 1024s in order to reduce network overhead.
+.PP
+In some cases it may not be practical for
+.B
+to run
+continuously.
+A common workaround has been to run the
+.Xr ntpdate 8
+program from a
+.Xr cron 8
+job at designated
+times.
+However, this program does not have the crafted signal
+processing, error checking and mitigation algorithms of
+.B .
+The
+q
+option is intended for this purpose.
+Setting this option will cause
+.B
+to exit just after
+setting the clock for the first time.
+The procedure for initially
+setting the clock is the same as in continuous mode; most
+applications will probably want to specify the
+.Cm iburst
+keyword with the
+.Ic server
+configuration command.
+With this
+keyword a volley of messages are exchanged to groom the data and
+the clock is set in about 10 s.
+If nothing is heard after a
+couple of minutes, the daemon times out and exits.
+After a suitable
+period of mourning, the
+.Xr ntpdate 8
+program may be
+retired.
+.PP
+When kernel support is available to discipline the clock
+frequency, which is the case for stock Solaris, Tru64, Linux and
+.Fx ,
+a useful feature is available to discipline the clock
+frequency.
+First,
+.B
+is run in continuous mode with
+selected servers in order to measure and record the intrinsic clock
+frequency offset in the frequency file.
+It may take some hours for
+the frequency and offset to settle down.
+Then the
+.B
+is
+stopped and run in one-time mode as required.
+At each startup, the
+frequency is read from the file and initializes the kernel
+frequency.
+.SS "Poll Interval Control"
+This version of NTP includes an intricate state machine to
+reduce the network load while maintaining a quality of
+synchronization consistent with the observed jitter and wander.
+There are a number of ways to tailor the operation in order enhance
+accuracy by reducing the interval or to reduce network overhead by
+increasing it.
+However, the user is advised to carefully consider
+the consequences of changing the poll adjustment range from the
+default minimum of 64 s to the default maximum of 1,024 s.
+The
+default minimum can be changed with the
+.Ic tinker
+.Cm minpoll
+command to a value not less than 16 s.
+This value is used for all
+configured associations, unless overridden by the
+.Cm minpoll
+option on the configuration command.
+Note that most device drivers
+will not operate properly if the poll interval is less than 64 s
+and that the broadcast server and manycast client associations will
+also use the default, unless overridden.
+.PP
+In some cases involving dial up or toll services, it may be
+useful to increase the minimum interval to a few tens of minutes
+and maximum interval to a day or so.
+Under normal operation
+conditions, once the clock discipline loop has stabilized the
+interval will be increased in steps from the minimum to the
+maximum.
+However, this assumes the intrinsic clock frequency error
+is small enough for the discipline loop correct it.
+The capture
+range of the loop is 500 PPM at an interval of 64s decreasing by a
+factor of two for each doubling of interval.
+At a minimum of 1,024
+s, for example, the capture range is only 31 PPM.
+If the intrinsic
+error is greater than this, the drift file
+.Pa ntp.drift
+will
+have to be specially tailored to reduce the residual error below
+this limit.
+Once this is done, the drift file is automatically
+updated once per hour and is available to initialize the frequency
+on subsequent daemon restarts.
+.SS "The huff-n'-puff Filter"
+In scenarios where a considerable amount of data are to be
+downloaded or uploaded over telephone modems, timekeeping quality
+can be seriously degraded.
+This occurs because the differential
+delays on the two directions of transmission can be quite large.
+In
+many cases the apparent time errors are so large as to exceed the
+step threshold and a step correction can occur during and after the
+data transfer is in progress.
+.PP
+The huff-n'-puff filter is designed to correct the apparent time
+offset in these cases.
+It depends on knowledge of the propagation
+delay when no other traffic is present.
+In common scenarios this
+occurs during other than work hours.
+The filter maintains a shift
+register that remembers the minimum delay over the most recent
+interval measured usually in hours.
+Under conditions of severe
+delay, the filter corrects the apparent offset using the sign of
+the offset and the difference between the apparent delay and
+minimum delay.
+The name of the filter reflects the negative (huff)
+and positive (puff) correction, which depends on the sign of the
+offset.
+.PP
+The filter is activated by the
+.Ic tinker
+command and
+.Cm huffpuff
+keyword, as described in
+.Xr ntp.conf 5 .
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH FILES
+.TP
+.BR Pa /etc/ntp.conf
+the default name of the configuration file
+.TP
+.BR Pa /etc/ntp.drift
+the default name of the drift file
+.TP
+.BR Pa /etc/ntp.keys
+the default name of the key file
.SH "EXIT STATUS"
One of the following exit values will be returned:
.TP
.BR 1 " (EXIT_FAILURE)"
The operation failed or the command syntax was not valid.
.SH "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpdate 8 ,
+.Xr ntpdc 8 ,
+.Xr ntpq 8
+.PP
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+.Li http://www.ntp.org/ .
+A snapshot of this documentation is available in HTML format in
+.Pa /usr/share/doc/ntp .
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 1)
+.%O RFC1059
+.Re
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 2)
+.%O RFC1119
+.Re
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 3)
+.%O RFC1305
+.Re
+.Rs
+.%A David L. Mills
+.%A J. Martin, Ed.
+.%A J. Burbank
+.%A W. Kasch
+.%T Network Time Protocol Version 4: Protocol and Algorithms Specification
+.%O RFC5905
+.Re
+.Rs
+.%A David L. Mills
+.%A B. Haberman, Ed.
+.%T Network Time Protocol Version 4: Autokey Specification
+.%O RFC5906
+.Re
+.Rs
+.%A H. Gerstung
+.%A C. Elliott
+.%A B. Haberman, Ed.
+.%T Definitions of Managed Objects for Network Time Protocol Version 4: (NTPv4)
+.%O RFC5907
+.Re
+.Rs
+.%A R. Gayraud
+.%A B. Lourdelet
+.%T Network Time Protocol (NTP) Server Option for DHCPv6
+.%O RFC5908
+.Re
.SH "AUTHORS"
The University of Delaware
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The
+.B
+utility has gotten rather fat.
+While not huge, it has gotten
+larger than might be desirable for an elevated-priority
+.B
+running on a workstation, particularly since many of
+the fancy features which consume the space were designed more with
+a busy primary server, rather than a high stratum workstation in
+mind.Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
+Portions of this document came from FreeBSD.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntpd\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTPD @NTPD_MS@ User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntpd-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:19:48 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:34 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpd-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
[ <server1> ... <serverN> ]
.Pp
.Sh DESCRIPTION
+The
+.Nm
+utility is an operating system daemon which sets
+and maintains the system time of day in synchronism with Internet
+standard time servers.
+It is a complete implementation of the
+Network Time Protocol (NTP) version 4, as defined by RFC-5905,
+but also retains compatibility with
+version 3, as defined by RFC-1305, and versions 1
+and 2, as defined by RFC-1059 and RFC-1119, respectively.
+.Pp
+The
+.Nm
+utility does most computations in 64-bit floating point
+arithmetic and does relatively clumsy 64-bit fixed point operations
+only when necessary to preserve the ultimate precision, about 232
+picoseconds.
+While the ultimate precision is not achievable with
+ordinary workstations and networks of today, it may be required
+with future gigahertz CPU clocks and gigabit LANs.
+.Pp
+Ordinarily,
+.Nm
+reads the
+.Xr ntp.conf 5
+configuration file at startup time in order to determine the
+synchronization sources and operating modes.
+It is also possible to
+specify a working, although limited, configuration entirely on the
+command line, obviating the need for a configuration file.
+This may
+be particularly useful when the local host is to be configured as a
+broadcast/multicast client, with all peers being determined by
+listening to broadcasts at run time.
+.Pp
+If NetInfo support is built into
+.Nm ,
+then
+.Nm
+will attempt to read its configuration from the
+NetInfo if the default
+.Xr ntp.conf 5
+file cannot be read and no file is
+specified by the
+.Fl c
+option.
+.Pp
+Various internal
+.Nm
+variables can be displayed and
+configuration options altered while the
+.Nm
+is running
+using the
+.Xr ntpq 8
+and
+.Xr ntpdc 8
+utility programs.
+.Pp
+When
+.Nm
+starts it looks at the value of
+.Xr umask 2 ,
+and if zero
+.Nm
+will set the
+.Xr umask 2
+to 022.
.Sh "OPTIONS"
.Bl -tag
.It \-4 ", " -\-ipv4
.fi
.ad
.Sh USAGE
+.Ss "How NTP Operates"
+The
+.Nm
+utility operates by exchanging messages with
+one or more configured servers over a range of designated poll intervals.
+When
+started, whether for the first or subsequent times, the program
+requires several exchanges from the majority of these servers so
+the signal processing and mitigation algorithms can accumulate and
+groom the data and set the clock.
+In order to protect the network
+from bursts, the initial poll interval for each server is delayed
+an interval randomized over a few seconds.
+At the default initial poll
+interval of 64s, several minutes can elapse before the clock is
+set.
+This initial delay to set the clock
+can be safely and dramatically reduced using the
+.Cm iburst
+keyword with the
+.Ic server
+configuration
+command, as described in
+.Xr ntp.conf 5 .
+.Pp
+Most operating systems and hardware of today incorporate a
+time-of-year (TOY) chip to maintain the time during periods when
+the power is off.
+When the machine is booted, the chip is used to
+initialize the operating system time.
+After the machine has
+synchronized to a NTP server, the operating system corrects the
+chip from time to time.
+In the default case, if
+.Nm
+detects that the time on the host
+is more than 1000s from the server time,
+.Nm
+assumes something must be terribly wrong and the only
+reliable action is for the operator to intervene and set the clock
+by hand.
+(Reasons for this include there is no TOY chip,
+or its battery is dead, or that the TOY chip is just of poor quality.)
+This causes
+.Nm
+to exit with a panic message to
+the system log.
+The
+.Fl g
+option overrides this check and the
+clock will be set to the server time regardless of the chip time
+(up to 68 years in the past or future \(em
+this is a limitation of the NTPv4 protocol).
+However, and to protect against broken hardware, such as when the
+CMOS battery fails or the clock counter becomes defective, once the
+clock has been set an error greater than 1000s will cause
+.Nm
+to exit anyway.
+.Pp
+Under ordinary conditions,
+.Nm
+adjusts the clock in
+small steps so that the timescale is effectively continuous and
+without discontinuities.
+Under conditions of extreme network
+congestion, the roundtrip delay jitter can exceed three seconds and
+the synchronization distance, which is equal to one-half the
+roundtrip delay plus error budget terms, can become very large.
+The
+.Nm
+algorithms discard sample offsets exceeding 128 ms,
+unless the interval during which no sample offset is less than 128
+ms exceeds 900s.
+The first sample after that, no matter what the
+offset, steps the clock to the indicated time.
+In practice this
+reduces the false alarm rate where the clock is stepped in error to
+a vanishingly low incidence.
+.Pp
+As the result of this behavior, once the clock has been set it
+very rarely strays more than 128 ms even under extreme cases of
+network path congestion and jitter.
+Sometimes, in particular when
+.Nm
+is first started without a valid drift file
+on a system with a large intrinsic drift
+the error might grow to exceed 128 ms,
+which would cause the clock to be set backwards
+if the local clock time is more than 128 s
+in the future relative to the server.
+In some applications, this behavior may be unacceptable.
+There are several solutions, however.
+If the
+.Fl x
+option is included on the command line, the clock will
+never be stepped and only slew corrections will be used.
+But this choice comes with a cost that
+should be carefully explored before deciding to use
+the
+.Fl x
+option.
+The maximum slew rate possible is limited
+to 500 parts-per-million (PPM) as a consequence of the correctness
+principles on which the NTP protocol and algorithm design are
+based.
+As a result, the local clock can take a long time to
+converge to an acceptable offset, about 2,000 s for each second the
+clock is outside the acceptable range.
+During this interval the
+local clock will not be consistent with any other network clock and
+the system cannot be used for distributed applications that require
+correctly synchronized network time.
+.Pp
+In spite of the above precautions, sometimes when large
+frequency errors are present the resulting time offsets stray
+outside the 128-ms range and an eventual step or slew time
+correction is required.
+If following such a correction the
+frequency error is so large that the first sample is outside the
+acceptable range,
+.Nm
+enters the same state as when the
+.Pa ntp.drift
+file is not present.
+The intent of this behavior
+is to quickly correct the frequency and restore operation to the
+normal tracking mode.
+In the most extreme cases
+(the host
+.Cm time.ien.it
+comes to mind), there may be occasional
+step/slew corrections and subsequent frequency corrections.
+It
+helps in these cases to use the
+.Cm burst
+keyword when
+configuring the server, but
+ONLY
+when you have permission to do so from the owner of the target host.
+.Pp
+Finally,
+in the past many startup scripts would run
+.Xr ntpdate 8
+to get the system clock close to correct before starting
+.Xr ntpd 8 ,
+but this was never more than a mediocre hack and is no longer needed.
+.Pp
+There is a way to start
+.Xr ntpd 8
+that often addresses all of the problems mentioned above.
+.Ss "Starting NTP (Best Current Practice)"
+First, use the
+.Cm iburst
+option on your
+.Cm server
+entries.
+.Pp
+If you can also keep a good
+.Pa ntp.drift
+file then
+.Xr ntpd 8
+will effectively "warm-start" and your system's clock will
+be stable in under 11 seconds' time.
+.Pp
+As soon as possible in the startup sequence, start
+.Xr ntpd 8
+with at least the
+.Fl g
+and perhaps the
+.Fl N
+options.
+Then,
+start the rest of your "normal" processes.
+This will give
+.Xr ntpd 8
+as much time as possible to get the system's clock synchronized and stable.
+.Pp
+Finally,
+if you have processes like
+.Cm dovecot
+or database servers
+that require
+monotonically-increasing time,
+run
+.Xr ntp-wait 8
+as late as possible in the boot sequence
+(perhaps with the
+.Fl v
+flag)
+and after
+.Xr ntp-wait 8
+exits successfully
+it is as safe as it will ever be to start any process that require
+stable time.
+.Ss "Frequency Discipline"
+The
+.Nm
+behavior at startup depends on whether the
+frequency file, usually
+.Pa ntp.drift ,
+exists.
+This file
+contains the latest estimate of clock frequency error.
+When the
+.Nm
+is started and the file does not exist, the
+.Nm
+enters a special mode designed to quickly adapt to
+the particular system clock oscillator time and frequency error.
+This takes approximately 15 minutes, after which the time and
+frequency are set to nominal values and the
+.Nm
+enters
+normal mode, where the time and frequency are continuously tracked
+relative to the server.
+After one hour the frequency file is
+created and the current frequency offset written to it.
+When the
+.Nm
+is started and the file does exist, the
+.Nm
+frequency is initialized from the file and enters normal mode
+immediately.
+After that the current frequency offset is written to
+the file at hourly intervals.
+.Ss "Operating Modes"
+The
+.Nm
+utility can operate in any of several modes, including
+symmetric active/passive, client/server broadcast/multicast and
+manycast, as described in the
+.Qq Association Management
+page
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp ) .
+It normally operates continuously while
+monitoring for small changes in frequency and trimming the clock
+for the ultimate precision.
+However, it can operate in a one-time
+mode where the time is set from an external server and frequency is
+set from a previously recorded frequency file.
+A
+broadcast/multicast or manycast client can discover remote servers,
+compute server-client propagation delay correction factors and
+configure itself automatically.
+This makes it possible to deploy a
+fleet of workstations without specifying configuration details
+specific to the local environment.
+.Pp
+By default,
+.Nm
+runs in continuous mode where each of
+possibly several external servers is polled at intervals determined
+by an intricate state machine.
+The state machine measures the
+incidental roundtrip delay jitter and oscillator frequency wander
+and determines the best poll interval using a heuristic algorithm.
+Ordinarily, and in most operating environments, the state machine
+will start with 64s intervals and eventually increase in steps to
+1024s.
+A small amount of random variation is introduced in order to
+avoid bunching at the servers.
+In addition, should a server become
+unreachable for some time, the poll interval is increased in steps
+to 1024s in order to reduce network overhead.
+.Pp
+In some cases it may not be practical for
+.Nm
+to run
+continuously.
+A common workaround has been to run the
+.Xr ntpdate 8
+program from a
+.Xr cron 8
+job at designated
+times.
+However, this program does not have the crafted signal
+processing, error checking and mitigation algorithms of
+.Nm .
+The
+.Fl q
+option is intended for this purpose.
+Setting this option will cause
+.Nm
+to exit just after
+setting the clock for the first time.
+The procedure for initially
+setting the clock is the same as in continuous mode; most
+applications will probably want to specify the
+.Cm iburst
+keyword with the
+.Ic server
+configuration command.
+With this
+keyword a volley of messages are exchanged to groom the data and
+the clock is set in about 10 s.
+If nothing is heard after a
+couple of minutes, the daemon times out and exits.
+After a suitable
+period of mourning, the
+.Xr ntpdate 8
+program may be
+retired.
+.Pp
+When kernel support is available to discipline the clock
+frequency, which is the case for stock Solaris, Tru64, Linux and
+.Fx ,
+a useful feature is available to discipline the clock
+frequency.
+First,
+.Nm
+is run in continuous mode with
+selected servers in order to measure and record the intrinsic clock
+frequency offset in the frequency file.
+It may take some hours for
+the frequency and offset to settle down.
+Then the
+.Nm
+is
+stopped and run in one-time mode as required.
+At each startup, the
+frequency is read from the file and initializes the kernel
+frequency.
+.Ss "Poll Interval Control"
+This version of NTP includes an intricate state machine to
+reduce the network load while maintaining a quality of
+synchronization consistent with the observed jitter and wander.
+There are a number of ways to tailor the operation in order enhance
+accuracy by reducing the interval or to reduce network overhead by
+increasing it.
+However, the user is advised to carefully consider
+the consequences of changing the poll adjustment range from the
+default minimum of 64 s to the default maximum of 1,024 s.
+The
+default minimum can be changed with the
+.Ic tinker
+.Cm minpoll
+command to a value not less than 16 s.
+This value is used for all
+configured associations, unless overridden by the
+.Cm minpoll
+option on the configuration command.
+Note that most device drivers
+will not operate properly if the poll interval is less than 64 s
+and that the broadcast server and manycast client associations will
+also use the default, unless overridden.
+.Pp
+In some cases involving dial up or toll services, it may be
+useful to increase the minimum interval to a few tens of minutes
+and maximum interval to a day or so.
+Under normal operation
+conditions, once the clock discipline loop has stabilized the
+interval will be increased in steps from the minimum to the
+maximum.
+However, this assumes the intrinsic clock frequency error
+is small enough for the discipline loop correct it.
+The capture
+range of the loop is 500 PPM at an interval of 64s decreasing by a
+factor of two for each doubling of interval.
+At a minimum of 1,024
+s, for example, the capture range is only 31 PPM.
+If the intrinsic
+error is greater than this, the drift file
+.Pa ntp.drift
+will
+have to be specially tailored to reduce the residual error below
+this limit.
+Once this is done, the drift file is automatically
+updated once per hour and is available to initialize the frequency
+on subsequent daemon restarts.
+.Ss "The huff-n'-puff Filter"
+In scenarios where a considerable amount of data are to be
+downloaded or uploaded over telephone modems, timekeeping quality
+can be seriously degraded.
+This occurs because the differential
+delays on the two directions of transmission can be quite large.
+In
+many cases the apparent time errors are so large as to exceed the
+step threshold and a step correction can occur during and after the
+data transfer is in progress.
+.Pp
+The huff-n'-puff filter is designed to correct the apparent time
+offset in these cases.
+It depends on knowledge of the propagation
+delay when no other traffic is present.
+In common scenarios this
+occurs during other than work hours.
+The filter maintains a shift
+register that remembers the minimum delay over the most recent
+interval measured usually in hours.
+Under conditions of severe
+delay, the filter corrects the apparent offset using the sign of
+the offset and the difference between the apparent delay and
+minimum delay.
+The name of the filter reflects the negative (huff)
+and positive (puff) correction, which depends on the sign of the
+offset.
+.Pp
+The filter is activated by the
+.Ic tinker
+command and
+.Cm huffpuff
+keyword, as described in
+.Xr ntp.conf 5 .
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh FILES
+.Bl -tag -width /etc/ntp.drift -compact
+.It Pa /etc/ntp.conf
+the default name of the configuration file
+.It Pa /etc/ntp.drift
+the default name of the drift file
+.It Pa /etc/ntp.keys
+the default name of the key file
+.El
.Sh "EXIT STATUS"
One of the following exit values will be returned:
.Bl -tag
The operation failed or the command syntax was not valid.
.El
.Sh "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpdate 8 ,
+.Xr ntpdc 8 ,
+.Xr ntpq 8
+.Pp
+In addition to the manual pages provided,
+comprehensive documentation is available on the world wide web
+at
+.Li http://www.ntp.org/ .
+A snapshot of this documentation is available in HTML format in
+.Pa /usr/share/doc/ntp .
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 1)
+.%O RFC1059
+.Re
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 2)
+.%O RFC1119
+.Re
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 3)
+.%O RFC1305
+.Re
+.Rs
+.%A David L. Mills
+.%A J. Martin, Ed.
+.%A J. Burbank
+.%A W. Kasch
+.%T Network Time Protocol Version 4: Protocol and Algorithms Specification
+.%O RFC5905
+.Re
+.Rs
+.%A David L. Mills
+.%A B. Haberman, Ed.
+.%T Network Time Protocol Version 4: Autokey Specification
+.%O RFC5906
+.Re
+.Rs
+.%A H. Gerstung
+.%A C. Elliott
+.%A B. Haberman, Ed.
+.%T Definitions of Managed Objects for Network Time Protocol Version 4: (NTPv4)
+.%O RFC5907
+.Re
+.Rs
+.%A R. Gayraud
+.%A B. Lourdelet
+.%T Network Time Protocol (NTP) Server Option for DHCPv6
+.%O RFC5908
+.Re
.Sh "AUTHORS"
The University of Delaware
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The
+.Nm
+utility has gotten rather fat.
+While not huge, it has gotten
+larger than might be desirable for an elevated-priority
+.Nm
+running on a workstation, particularly since many of
+the fancy features which consume the space were designed more with
+a busy primary server, rather than a high stratum workstation in
+mind.Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
+Portions of this document came from FreeBSD.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntpd\fP
option definitions.
#
# EDIT THIS FILE WITH CAUTION (invoke-ntpdc.texi)
#
-# It has been AutoGen-ed January 2, 2013 at 02:20:16 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:09:56 PM by AutoGen 5.17.1pre11
# From the definitions ntpdc-opts.def
# and the template file agtexi-cmd.tpl
@end ignore
@exampleindent 0
@example
-ntpdc - vendor-specific NTPD control program - Ver. 4.2.7p343
+ntpdc - vendor-specific NTPD control program - Ver. 4.2.7p344
USAGE: ntpdc [ -<flag> [<val>] | --<name>[@{=| @}<val>] ]... [ host ...]
Flg Arg Option-Name Description
-4 no ipv4 Force IPv4 DNS name resolution
identifier.
Note that in contexts where a host name is expected, a
-@code{-4} qualifier preceding the host name forces DNS resolution to the IPv4 namespace,
+@code{-4}
+qualifier preceding the host name forces DNS resolution to the IPv4 namespace,
while a
-@code{-6} qualifier forces DNS resolution to the IPv6 namespace.
+@code{-6}
+qualifier forces DNS resolution to the IPv6 namespace.
Specifying a command line option other than
-@code{-i} or
-@code{-n} will cause the specified query (queries) to be sent to
+@code{-i}
+or
+@code{-n}
+will cause the specified query (queries) to be sent to
the indicated host(s) immediately.
Otherwise,
@code{ntpdc}
@node Interactive Commands
@section Interactive Commands
-Interactive Commands
+
Interactive format commands consist of a keyword followed by zero
to four arguments.
Only enough characters of the full keyword to
The output of a
command is normally sent to the standard output, but optionally the
output of individual commands may be sent to a file by appending a
-@quoteleft{}\&>@quoteright{},
+@quoteleft{}>,@quoteright{}
followed by a file name, to the command line.
A number of interactive format commands are executed entirely
mode 7 requests being sent to a server.
These are described
following.
-@table @samp
-@item Ic
-@item Ic
+@table @asis
+
+@item @code{?} @kbd{command_keyword}
+@item @code{help} @kbd{command_keyword}
A
-@quoteleft{}Ic \&?@quoteright{}
+@quoteleft{}@code{?}@quoteright{}
will print a list of all the command
keywords known to this incarnation of
@code{ntpdc}.
A
-@quoteleft{}Ic \&?@quoteright{}
+@quoteleft{}@code{?}@quoteright{}
followed by a command keyword will print function and usage
information about the command.
This command is probably a better
@code{ntpq(8)}
than this manual
page.
-@item Ic
+@item @code{delay} @kbd{milliseconds}
Specify a time interval to be added to timestamps included in
requests which require authentication.
This is used to enable
Actually the
server does not now require timestamps in authenticated requests,
so this command may be obsolete.
-@item Ic
+@item @code{host} @kbd{hostname}
Set the host to which future queries will be sent.
Hostname may
be either a host name or a numeric address.
-@item Ic
+@item @code{hostnames} [@code{yes} | @code{Cm} @code{no}]
If
-@code{yes} is specified, host names are printed in
+@code{yes}
+is specified, host names are printed in
information displays.
If
-@code{no} is specified, numeric
+@code{no}
+is specified, numeric
addresses are printed instead.
The default is
-@code{yes}, unless
+@code{yes},
+unless
modified using the command line
-@code{-n} switch.
-@item Ic
+@code{-n}
+switch.
+@item @code{keyid} @kbd{keyid}
This command allows the specification of a key number to be
used to authenticate configuration requests.
This must correspond
to a key number the server has been configured to use for this
purpose.
-@item Ic
+@item @code{quit}
Exit
@code{ntpdc}.
-@item Ic
+@item @code{passwd}
This command prompts you to type in a password (which will not
be echoed) which will be used to authenticate configuration
requests.
The password must correspond to the key configured for
use by the NTP server for this purpose if such requests are to be
successful.
-@item Ic
+@item @code{timeout} @kbd{milliseconds}
Specify a timeout period for responses to server queries.
The
default is about 8000 milliseconds.
@node Control Message Commands
@section Control Message Commands
-Control Message Commands
+
Query commands result in NTP mode 7 packets containing requests for
information being sent to the server.
These are read-only commands
in that they make no modification of the server configuration
state.
-@table @samp
-@item Ic
+@table @asis
+
+@item @code{listpeers}
Obtains and prints a brief list of the peers for which the
server is maintaining state.
These should include all configured
peer associations as well as those peers whose stratum is such that
they are considered by the server to be possible future
synchronization candidates.
-@item Ic
+@item @code{peers}
Obtains a list of peers for which the server is maintaining
state, along with a summary of that state.
Summary information
The character in the left margin indicates the mode this peer
entry is operating in.
A
-@quoteleft{}\&+@quoteright{}
+@quoteleft{}+@quoteright{}
denotes symmetric active, a
-@quoteleft{}\&-@quoteright{}
+@quoteleft{}-@quoteright{}
indicates symmetric passive, a
-@quoteleft{}\&=@quoteright{}
+@quoteleft{}=@quoteright{}
means the
remote server is being polled in client mode, a
-@quoteleft{}\&^@quoteright{}
+@quoteleft{}^@quoteright{}
indicates that the server is broadcasting to this address, a
-@quoteleft{}\&~@quoteright{}
+@quoteleft{}~@quoteright{}
denotes that the remote peer is sending broadcasts and a
-@quoteleft{}\&~@quoteright{}
+@quoteleft{}~@quoteright{}
denotes that the remote peer is sending broadcasts and a
-@quoteleft{}\&*@quoteright{}
+@quoteleft{}*@quoteright{}
marks the peer the server is currently synchronizing
to.
It may
be a host name, an IP address, a reference clock implementation
name with its parameter or
-@code{REFCLK}(@emph{implementation_number}@code{, }@emph{parameter}).
+@code{REFCLK}(@emph{implementation_number}@code{,} @emph{parameter}).
On
-@code{hostnames} @code{no} only IP-addresses
+@code{hostnames}
+@code{no}
+only IP-addresses
will be displayed.
-@item Ic
+@item @code{dmpeers}
A slightly different peer summary list.
Identical to the output
of the
-@code{peers} command, except for the character in the
+@code{peers}
+command, except for the character in the
leftmost column.
Characters only appear beside peers which were
included in the final stage of the clock selection algorithm.
A
-@quoteleft{}\&.@quoteright{}
+@quoteleft{}.@quoteright{}
indicates that this peer was cast off in the falseticker
detection, while a
-@quoteleft{}\&+@quoteright{}
+@quoteleft{}+@quoteright{}
indicates that the peer made it
through.
A
-@quoteleft{}\&*@quoteright{}
+@quoteleft{}*@quoteright{}
denotes the peer the server is currently
synchronizing with.
-@item Ic
+@item @code{showpeer} @kbd{peer_address} @kbd{Oo} @kbd{...} @kbd{Oc}
Shows a detailed display of the current peer variables for one
or more peers.
Most of these values are described in the NTP
Version 2 specification.
-@item Ic
+@item @code{pstats} @kbd{peer_address} @kbd{Oo} @kbd{...} @kbd{Oc}
Show per-peer statistic counters associated with the specified
peer(s).
-@item Ic
+@item @code{clockinfo} @kbd{clock_peer_address} @kbd{Oo} @kbd{...} @kbd{Oc}
Obtain and print information concerning a peer clock.
The
values obtained provide information on the setting of fudge factors
and other clock performance information.
-@item Ic
+@item @code{kerninfo}
Obtain and print kernel phase-lock loop operating parameters.
This information is available only if the kernel has been specially
modified for a precision timekeeping function.
-@item Ic
+@item @code{loopinfo} [@code{oneline} | @code{Cm} @code{multiline}]
Print the values of selected loop filter variables.
The loop
filter is the part of NTP which deals with adjusting the local
of seconds which have elapsed since the last sample offset was
given to the loop filter.
The
-@code{oneline} and
-@code{multiline} options specify the format in which this
+@code{oneline}
+and
+@code{multiline}
+options specify the format in which this
information is to be printed, with
-@code{multiline} as the
+@code{multiline}
+as the
default.
-@item Ic
+@item @code{sysinfo}
Print a variety of system state variables, i.e., state related
to the local server.
All except the last four lines are described
@quoteleft{}system flags@quoteright{}
show various system flags, some of
which can be set and cleared by the
-@code{enable} and
-@code{disable} configuration commands, respectively.
+@code{enable}
+and
+@code{disable}
+configuration commands, respectively.
These are
the
-@code{auth}, @code{bclient}, @code{monitor}, @code{pll}, @code{pps} and
-@code{stats} flags.
+@code{auth},
+@code{bclient},
+@code{monitor},
+@code{pll},
+@code{pps}
+and
+@code{stats}
+flags.
See the
@code{ntpd(8)}
documentation for the meaning of these flags.
There
are two additional flags which are read only, the
-@code{kernel_pll} and
-@code{kernel_pps}. These flags indicate
+@code{kernel_pll}
+and
+@code{kernel_pps}.
+These flags indicate
the synchronization status when the precision time kernel
modifications are in use.
The
If it remains high for some time after
starting the daemon, something may be wrong with the local clock,
or the value of the kernel variable
-.Va
-kern.clockrate.tick
+Va kern.clockrate.tick
may be
incorrect.
@quoteleft{}broadcastdelay@quoteright{}
shows the default broadcast delay,
as set by the
-@code{broadcastdelay} configuration command.
+@code{broadcastdelay}
+configuration command.
The
@quoteleft{}authdelay@quoteright{}
shows the default authentication delay,
as set by the
-@code{authdelay} configuration command.
-@item Ic
+@code{authdelay}
+configuration command.
+@item @code{sysstats}
Print statistics counters maintained in the protocol
module.
-@item Ic
+@item @code{memstats}
Print statistics counters related to memory allocation
code.
-@item Ic
+@item @code{iostats}
Print statistics counters maintained in the input-output
module.
-@item Ic
+@item @code{timerstats}
Print statistics counters maintained in the timer/event queue
support code.
-@item Ic
+@item @code{reslist}
Obtain and print the server's restriction list.
This list is
(usually) printed in sorted order and may help to understand how
the restrictions are applied.
-@item Ic
+@item @code{monlist} [@kbd{version}]
Obtain and print traffic counts collected and maintained by the
monitor facility.
The version number should not normally need to be
specified.
-@item Ic
+@item @code{clkbug} @kbd{clock_peer_address} @kbd{Oo} @kbd{...} @kbd{Oc}
Obtain debugging information for a reference clock driver.
This
information is provided only by some clock drivers and is mostly
@node Runtime Configuration Requests
@section Runtime Configuration Requests
-Runtime Configuration Requests
+
All requests which cause state changes in the server are
authenticated by the server using a configured NTP key (the
facility can also be disabled by the server by not configuring a
known to
@code{ntpdc}.
This can be done using the
-@code{keyid} and
-@code{passwd} commands, the latter of which will prompt at the terminal for a
+@code{keyid}
+and
+@code{passwd}
+commands, the latter of which will prompt at the terminal for a
password to use as the encryption key.
You will also be prompted
automatically for both the key number and password the first time a
adequate level of security.
The following commands all make authenticated requests.
-@table @samp
-@item Xo
-[@code{keyid} ]
-[@code{version} ]
-[@code{prefer} ]
+@table @asis
+
+@item @code{addpeer} @kbd{peer_address}[@kbd{keyid}][@kbd{version}][@code{prefer}]
Add a configured peer association at the given address and
operating in symmetric active mode.
Note that an existing
executed, or may simply be converted to conform to the new
configuration, as appropriate.
If the optional
-@code{keyid} is a
+@kbd{keyid}
+is a
nonzero integer, all outgoing packets to the remote server will
have an authentication field attached encrypted with this key.
If
the value is 0 (or not given) no authentication will be done.
The
-@code{version} can be 1, 2 or 3 and defaults to 3.
+@kbd{version}
+can be 1, 2 or 3 and defaults to 3.
The
-@code{prefer} keyword indicates a preferred peer (and thus will
+@code{prefer}
+keyword indicates a preferred peer (and thus will
be used primarily for clock synchronisation if possible).
The
preferred peer also determines the validity of the PPS signal - if
the preferred peer is suitable for synchronisation so is the PPS
signal.
-@item Xo
-[@code{keyid} ]
-[@code{version} ]
-[@code{prefer} ]
+@item @code{addserver} @kbd{peer_address}[@kbd{keyid}][@kbd{version}][@code{prefer}]
Identical to the addpeer command, except that the operating
mode is client.
-@item Xo
-[@code{keyid} ]
-[@code{version} ]
-[@code{prefer} ]
+@item @code{broadcast} @kbd{peer_address}[@kbd{keyid}][@kbd{version}][@code{prefer}]
Identical to the addpeer command, except that the operating
mode is broadcast.
In this case a valid key identifier and key are
required.
The
-@code{peer_address} parameter can be the broadcast
+@kbd{peer_address}
+parameter can be the broadcast
address of the local network or a multicast group address assigned
to NTP.
If a multicast address, a multicast-capable kernel is
required.
-@item Ic
+@item @code{unconfig} @kbd{peer_address} @kbd{Oo} @kbd{...} @kbd{Oc}
This command causes the configured bit to be removed from the
specified peer(s).
In many cases this will cause the peer
When appropriate, however, the
association may persist in an unconfigured mode if the remote peer
is willing to continue on in this fashion.
-@item Xo
-[@code{time1} ]
-[@code{time2} ]
-[@code{stratum} ]
-[@code{refid} ]
+@item @code{fudge} @kbd{peer_address}[@code{time1}][@code{time2}][@kbd{stratum}][@kbd{refid}]
This command provides a way to set certain data for a reference
clock.
See the source listing for further information.
-@item Xo
-.Oo
-@code{auth} | @code{Cm} @code{bclient} | @code{calibrate} | @code{Cm} @code{kernel} | @code{monitor} | @code{Cm} @code{ntp} | @code{pps} | @code{Cm} @code{stats} .Oc
-@item Xo
-.Oo
-@code{auth} | @code{Cm} @code{bclient} | @code{calibrate} | @code{Cm} @code{kernel} | @code{monitor} | @code{Cm} @code{ntp} | @code{pps} | @code{Cm} @code{stats} .Oc
+@item @code{enable}Oo@code{auth} | @code{Cm} @code{bclient} |@code{calibrate} | @code{Cm} @code{kernel} |@code{monitor} | @code{Cm} @code{ntp} |@code{pps} | @code{Cm} @code{stats}Oc
+@item @code{disable}Oo@code{auth} | @code{Cm} @code{bclient} |@code{calibrate} | @code{Cm} @code{kernel} |@code{monitor} | @code{Cm} @code{ntp} |@code{pps} | @code{Cm} @code{stats}Oc
These commands operate in the same way as the
-@code{enable} and
-@code{disable} configuration file commands of
+@code{enable}
+and
+@code{disable}
+configuration file commands of
@code{ntpd(8)}.
-@table @samp
-@item Cm
+@table @asis
+
+@item @code{auth}
Enables the server to synchronize with unconfigured peers only
if the peer has been correctly authenticated using either public key
or private key cryptography.
The default for this flag is enable.
-@item Cm
+@item @code{bclient}
Enables the server to listen for a message from a broadcast or
multicast server, as in the multicastclient command with
default address.
The default for this flag is disable.
-@item Cm
+@item @code{calibrate}
Enables the calibrate feature for reference clocks.
The default for this flag is disable.
-@item Cm
+@item @code{kernel}
Enables the kernel time discipline, if available.
The default for this flag is enable if support is available, otherwise disable.
-@item Cm
+@item @code{monitor}
Enables the monitoring facility.
See the
@code{ntpdc(8)}.
program and the monlist command or further information.
The default for this flag is enable.
-@item Cm
+@item @code{ntp}
Enables time and frequency discipline.
In effect, this switch opens and closes the feedback loop,
which is useful for testing.
The default for this flag is enable.
-@item Cm
+@item @code{pps}
Enables the pulse-per-second (PPS) signal when frequency
and time is disciplined by the precision time kernel modifications.
See the
@file{/usr/share/doc/ntp})
page for further information.
The default for this flag is disable.
-@item Cm
+@item @code{stats}
Enables the statistics facility.
See the
-@ref{Monitoring}Monitoring
-Options
+@ref{Monitoring Options}
section of
@code{ntp.conf(5)}
for further information.
The default for this flag is disable.
@end table
-.It
-Xo
-Ic
-restrict
-Ar
-address
-Ar
-mask
-@code{flag} @code{Oo} @code{...} @code{Oc} This command operates in the same way as the
-@code{restrict} configuration file commands of
+@item @code{restrict} @kbd{address} @kbd{mask}@kbd{flag} @kbd{Oo} @kbd{...} @kbd{Oc}
+This command operates in the same way as the
+@code{restrict}
+configuration file commands of
@code{ntpd(8)}.
-.It
-Xo
-Ic
-unrestrict
-Ar
-address
-Ar
-mask
-@code{flag} @code{Oo} @code{...} @code{Oc} Unrestrict the matching entry from the restrict list.
-.It
-Xo
-Ic
-delrestrict
-Ar
-address
-Ar
-mask
-[@code{ntpport} ]
+@item @code{unrestrict} @kbd{address} @kbd{mask}@kbd{flag} @kbd{Oo} @kbd{...} @kbd{Oc}
+Unrestrict the matching entry from the restrict list.
+@item @code{delrestrict} @kbd{address} @kbd{mask}[@code{ntpport}]
Delete the matching entry from the restrict list.
-.It
-Ic
-readkeys
+@item @code{readkeys}
Causes the current set of authentication keys to be purged and
a new set to be obtained by rereading the keys file (which must
have been specified in the
This
allows encryption keys to be changed without restarting the
server.
-.It
-Ic
-trustedkey
-Ar
-keyid
-Oo
-Ar
-...
-Oc
-.It
-Ic
-untrustedkey
-Ar
-keyid
-Oo
-Ar
-...
-Oc
+@item @code{trustedkey} @kbd{keyid} @kbd{Oo} @kbd{...} @kbd{Oc}
+@item @code{untrustedkey} @kbd{keyid} @kbd{Oo} @kbd{...} @kbd{Oc}
These commands operate in the same way as the
-@code{trustedkey} and
-@code{untrustedkey} configuration file
+@code{trustedkey}
+and
+@code{untrustedkey}
+configuration file
commands of
@code{ntpd(8)}.
-.It
-Ic
-authinfo
+@item @code{authinfo}
Returns information concerning the authentication module,
including known keys and counts of encryptions and decryptions
which have been done.
-.It
-Ic
-traps
+@item @code{traps}
Display the traps set in the server.
See the source listing for
further information.
-.It
-Xo
-Ic
-addtrap
-Ar
-address
-[@code{port} ]
-[@code{interface} ]
+@item @code{addtrap} @kbd{address}[@kbd{port}][@kbd{interface}]
Set a trap for asynchronous messages.
See the source listing
for further information.
-.It
-Xo
-Ic
-clrtrap
-Ar
-address
-[@code{port} ]
-[@code{interface} ]
+@item @code{clrtrap} @kbd{address}[@kbd{port}][@kbd{interface}]
Clear a trap for asynchronous messages.
See the source listing
for further information.
-.It
-Ic
-reset
+@item @code{reset}
Clear the statistics counters in various modules of the server.
See the source listing for further information.
-
-@end multitable
+@end table
@node ntpdc See Also
@subsection ntpdc See Also
@code{ntp.conf(5)},
@code{ntpd(8)}
-.Rs
-.%A
-David
-L.
-Mills
-.%T
-Network
-Time
-Protocol
-(Version
-3)
-.%O
-RFC1305
-.Re
+@*
+ David L. Mills, @emph{Network Time Protocol (Version 3)}, RFC1305.
@node ntpdc Authors
@subsection ntpdc Authors
The formatting directives in this document came from FreeBSD.
/*
* EDIT THIS FILE WITH CAUTION (ntpdc-opts.c)
*
- * It has been AutoGen-ed January 2, 2013 at 02:20:05 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:09:44 PM by AutoGen 5.17.1pre11
* From the definitions ntpdc-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This source file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* ntpdc option static const strings
*/
static char const ntpdc_opt_strs[1862] =
-/* 0 */ "ntpdc 4.2.7p343\n"
+/* 0 */ "ntpdc 4.2.7p344\n"
"Copyright (C) 1970-2013 The University of Delaware, all rights reserved.\n"
"This is free software. It is licensed for use, modification and\n"
"redistribution under the terms of the NTP License, copies of which\n"
/* 1640 */ "no-load-opts\0"
/* 1653 */ "no\0"
/* 1656 */ "NTPDC\0"
-/* 1662 */ "ntpdc - vendor-specific NTPD control program - Ver. 4.2.7p343\n"
+/* 1662 */ "ntpdc - vendor-specific NTPD control program - Ver. 4.2.7p344\n"
"USAGE: %s [ -<flag> [<val>] | --<name>[{=| }<val>] ]... [ host ...]\n\0"
/* 1794 */ "$HOME\0"
/* 1800 */ ".\0"
/* 1802 */ ".ntprc\0"
/* 1809 */ "http://bugs.ntp.org, bugs@ntp.org\0"
/* 1843 */ "\n\n\0"
-/* 1846 */ "ntpdc 4.2.7p343";
+/* 1846 */ "ntpdc 4.2.7p344";
/*
* ipv4 option description with
#define zExplain (ntpdc_opt_strs+1843)
#define zDetail (NULL)
#define zFullVersion (ntpdc_opt_strs+1846)
-/* extracted from optcode.tlib near line 350 */
+/* extracted from optcode.tlib near line 353 */
#if defined(ENABLE_NLS)
# define OPTPROC_BASE OPTPROC_TRANSLATE
static void
doOptDebug_Level(tOptions* pOptions, tOptDesc* pOptDesc)
{
+ /*
+ * Be sure the flag-code[0] handles special values for the options pointer
+ * viz. (poptions <= OPTPROC_EMIT_LIMIT) *and also* the special flag bit
+ * ((poptdesc->fOptState & OPTST_RESET) != 0) telling the option to
+ * reset its state.
+ */
/* extracted from debug-opt.def, line 15 */
OPT_VALUE_SET_DEBUG_LEVEL++;
(void)pOptDesc;
(void)pOptions;
}
#endif /* defined(TEST_NTPDC_OPTS) */
-/* extracted from optmain.tlib near line 48 */
+/* extracted from optmain.tlib near line 46 */
#if defined(TEST_NTPDC_OPTS) /* TEST MAIN PROCEDURE: */
return res;
}
#endif /* defined TEST_NTPDC_OPTS */
-/* extracted from optmain.tlib near line 1146 */
+/* extracted from optmain.tlib near line 1188 */
/**
* The directory containing the data associated with ntpdc.
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#ifdef HAVE_DCGETTEXT
+# include <gettext.h>
+#endif
#include <autoopts/usage-txt.h>
-static char* AO_gettext(char const* pz);
-static void coerce_it(void** s);
+static char * AO_gettext(char const * pz);
+static void coerce_it(void ** s);
/**
- * AutoGen specific wrapper function for gettext.
- * It relies on the macro _() to convert from English to the target
- * language, then strdup-duplicates the result string.
+ * AutoGen specific wrapper function for gettext. It relies on the macro _()
+ * to convert from English to the target language, then strdup-duplicates the
+ * result string. It tries the "libopts" domain first, then whatever has been
+ * set via the \a textdomain(3) call.
*
* @param[in] pz the input text used as a lookup key.
* @returns the translated text (if there is one),
* or the original text (if not).
*/
static char *
-AO_gettext(char const* pz)
+AO_gettext(char const * pz)
{
- char* pzRes;
+ char * res;
if (pz == NULL)
return NULL;
- pzRes = _(pz);
- if (pzRes == pz)
- return pzRes;
- pzRes = strdup(pzRes);
- if (pzRes == NULL) {
+#ifdef HAVE_DCGETTEXT
+ /*
+ * While processing the option_xlateable_txt data, try to use the
+ * "libopts" domain. Once we switch to the option descriptor data,
+ * do *not* use that domain.
+ */
+ if (option_xlateable_txt.field_ct != 0) {
+ res = dgettext("libopts", pz);
+ if (res == pz)
+ res = (char *)(void *)_(pz);
+ } else
+ res = (char *)(void *)_(pz);
+#else
+ res = (char *)(void *)_(pz);
+#endif
+ if (res == pz)
+ return res;
+ res = strdup(res);
+ if (res == NULL) {
fputs(_("No memory for duping translated strings\n"), stderr);
exit(NTPDC_EXIT_FAILURE);
}
- return pzRes;
+ return res;
}
-static void coerce_it(void** s) { *s = AO_gettext(*s);
+/**
+ * All the pointers we use are marked "* const", but they are stored in
+ * writable memory. Coerce the mutability and set the pointer.
+ */
+static void coerce_it(void ** s) { *s = AO_gettext(*s);
}
/**
static void
translate_option_strings(void)
{
- tOptions * const pOpt = &ntpdcOptions;
+ tOptions * const opts = &ntpdcOptions;
/*
* Guard against re-translation. It won't work. The strings will have
* been changed by the first pass through this code. One shot only.
*/
- if (option_usage_text.field_ct != 0) {
+ if (option_xlateable_txt.field_ct != 0) {
/*
* Do the translations. The first pointer follows the field count
* field. The field count field is the size of a pointer.
*/
- tOptDesc * pOD = pOpt->pOptDesc;
- char ** ppz = (char**)(void*)&(option_usage_text);
- int ix = option_usage_text.field_ct;
+ tOptDesc * od = opts->pOptDesc;
+ char ** ppz = (char**)(void*)&(option_xlateable_txt);
+ int ix = option_xlateable_txt.field_ct;
do {
- ppz++;
+ ppz++; /* skip over field_ct */
*ppz = AO_gettext(*ppz);
} while (--ix > 0);
-
- coerce_it((void*)&(pOpt->pzCopyright));
- coerce_it((void*)&(pOpt->pzCopyNotice));
- coerce_it((void*)&(pOpt->pzFullVersion));
- coerce_it((void*)&(pOpt->pzUsageTitle));
- coerce_it((void*)&(pOpt->pzExplain));
- coerce_it((void*)&(pOpt->pzDetail));
- coerce_it((void*)&(pOpt->pzPackager));
- option_usage_text.field_ct = 0;
-
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++)
- coerce_it((void*)&(pOD->pzText));
+ /* prevent re-translation and disable "libopts" domain lookup */
+ option_xlateable_txt.field_ct = 0;
+
+ coerce_it((void*)&(opts->pzCopyright));
+ coerce_it((void*)&(opts->pzCopyNotice));
+ coerce_it((void*)&(opts->pzFullVersion));
+ coerce_it((void*)&(opts->pzUsageTitle));
+ coerce_it((void*)&(opts->pzExplain));
+ coerce_it((void*)&(opts->pzDetail));
+ coerce_it((void*)&(opts->pzPackager));
+
+ for (ix = opts->optCt; ix > 0; ix--, od++)
+ coerce_it((void*)&(od->pzText));
}
- if ((pOpt->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
- tOptDesc * pOD = pOpt->pOptDesc;
+ if ((opts->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
+ tOptDesc * od = opts->pOptDesc;
int ix;
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++) {
- coerce_it((void*)&(pOD->pz_Name));
- coerce_it((void*)&(pOD->pz_DisableName));
- coerce_it((void*)&(pOD->pz_DisablePfx));
+ for (ix = opts->optCt; ix > 0; ix--, od++) {
+ coerce_it((void*)&(od->pz_Name));
+ coerce_it((void*)&(od->pz_DisableName));
+ coerce_it((void*)&(od->pz_DisablePfx));
}
- /* prevent re-translation */
ntpdcOptions.fOptSet |= OPTPROC_NXLAT_OPT_CFG | OPTPROC_NXLAT_OPT;
}
}
/*
* EDIT THIS FILE WITH CAUTION (ntpdc-opts.h)
*
- * It has been AutoGen-ed January 2, 2013 at 02:20:04 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:09:44 PM by AutoGen 5.17.1pre11
* From the definitions ntpdc-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This header file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* tolerable version is at least as old as what was current when the header
* template was released.
*/
-#define AO_TEMPLATE_VERSION 147461
+#define AO_TEMPLATE_VERSION 151552
#if (AO_TEMPLATE_VERSION < OPTIONS_MINIMUM_VERSION) \
|| (AO_TEMPLATE_VERSION > OPTIONS_STRUCT_VERSION)
# error option template version mismatches autoopts/options.h header
} teOptIndex;
#define OPTION_CT 15
-#define NTPDC_VERSION "4.2.7p343"
-#define NTPDC_FULL_VERSION "ntpdc 4.2.7p343"
+#define NTPDC_VERSION "4.2.7p344"
+#define NTPDC_FULL_VERSION "ntpdc 4.2.7p344"
/*
* Interface defines for all options. Replace "n" with the UPPER_CASED
* Enumeration of ntpdc exit codes
*/
typedef enum {
- NTPDC_EXIT_SUCCESS = 0,
- NTPDC_EXIT_FAILURE = 1,
- NTPDC_EXIT_NO_CONFIG_INPUT = 66,
- NTPDC_EXIT_LIBOPTS_FAILURE = 70
+ NTPDC_EXIT_SUCCESS = 0,
+ NTPDC_EXIT_FAILURE = 1,
+ NTPDC_EXIT_USAGE_ERROR = 64,
+ NTPDC_EXIT_NO_CONFIG_INPUT = 66,
+ NTPDC_EXIT_LIBOPTS_FAILURE = 70
} ntpdc_exit_code_t;
/*
* Make sure there are no #define name conflicts with the option names
#define SET_OPT_SAVE_OPTS(a) STMTS( \
DESC(SAVE_OPTS).fOptState &= OPTST_PERSISTENT_MASK; \
DESC(SAVE_OPTS).fOptState |= OPTST_SET; \
- DESC(SAVE_OPTS).optArg.argString = (char const*)(a) )
+ DESC(SAVE_OPTS).optArg.argString = (char const*)(a))
/*
* Interface defines not associated with particular options
*/
ntpdcOptions.pzCurOpt = NULL)
#define START_OPT RESTART_OPT(1)
#define USAGE(c) (*ntpdcOptions.pUsageProc)(&ntpdcOptions, c)
-/* extracted from opthead.tlib near line 484 */
+/* extracted from opthead.tlib near line 497 */
#ifdef __cplusplus
extern "C" {
-.TH ntpdc 1ntpdcman "02 Jan 2013" "4.2.7p343" "User Commands"
+.TH ntpdc 1ntpdcman "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntpdc-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:12 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:52 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpdc-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntpdc
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..." [ host ...]
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..." " " "[ host ...]"
.PP
.SH DESCRIPTION
+.B
+is a utility program used to query
+.Xr ntpd 8
+about its
+current state and to request changes in that state.
+It uses NTP mode 7 control message formats described in the source code.
+The program may
+be run either in interactive mode or controlled using command line
+arguments.
+Extensive state and statistics information is available
+through the
+.B
+interface.
+In addition, nearly all the
+configuration options which can be specified at startup using
+ntpd's configuration file may also be specified at run time using
+.B .
.SH "OPTIONS"
.TP
.BR \-4 ", " -\-ipv4
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.SH USAGE
+If one or more request options are included on the command line
+when
+.B
+is executed, each of the requests will be sent
+to the NTP servers running on each of the hosts given as command
+line arguments, or on localhost by default.
+If no request options
+are given,
+.B
+will attempt to read commands from the
+standard input and execute these on the NTP server running on the
+first host given on the command line, again defaulting to localhost
+when no other host is specified.
+The
+.B
+utility will prompt for
+commands if the standard input is a terminal device.
+.PP
+The
+.B
+utility uses NTP mode 7 packets to communicate with the
+NTP server, and hence can be used to query any compatible server on
+the network which permits it.
+Note that since NTP is a UDP protocol
+this communication will be somewhat unreliable, especially over
+large distances in terms of network topology.
+The
+.B
+utility makes
+no attempt to retransmit requests, and will time requests out if
+the remote host is not heard from within a suitable timeout
+time.
+.PP
+The operation of
+.B
+are specific to the particular
+implementation of the
+.Xr ntpd 8
+daemon and can be expected to
+work only with this and maybe some previous versions of the daemon.
+Requests from a remote
+.B
+utility which affect the
+state of the local server must be authenticated, which requires
+both the remote program and local server share a common key and key
+identifier.
+.PP
+Note that in contexts where a host name is expected, a
+4
+qualifier preceding the host name forces DNS resolution to the IPv4 namespace,
+while a
+6
+qualifier forces DNS resolution to the IPv6 namespace.
+Specifying a command line option other than
+i
+or
+n
+will cause the specified query (queries) to be sent to
+the indicated host(s) immediately.
+Otherwise,
+.B
+will
+attempt to read interactive format commands from the standard
+input.
+.SS "Interactive Commands"
+Interactive format commands consist of a keyword followed by zero
+to four arguments.
+Only enough characters of the full keyword to
+uniquely identify the command need be typed.
+The output of a
+command is normally sent to the standard output, but optionally the
+output of individual commands may be sent to a file by appending a
+.Ql \&> ,
+followed by a file name, to the command line.
+.PP
+A number of interactive format commands are executed entirely
+within the
+.B
+utility itself and do not result in NTP
+mode 7 requests being sent to a server.
+These are described
+following.
+.TP
+.BR Ic \&? Ar command_keyword
+.TP
+.BR Ic help Ar command_keyword
+A
+.Sq Ic \&?
+will print a list of all the command
+keywords known to this incarnation of
+.Nm .
+A
+.Sq Ic \&?
+followed by a command keyword will print function and usage
+information about the command.
+This command is probably a better
+source of information about
+.Xr ntpq 8
+than this manual
+page.
+.TP
+.BR Ic delay Ar milliseconds
+Specify a time interval to be added to timestamps included in
+requests which require authentication.
+This is used to enable
+(unreliable) server reconfiguration over long delay network paths
+or between machines whose clocks are unsynchronized.
+Actually the
+server does not now require timestamps in authenticated requests,
+so this command may be obsolete.
+.TP
+.BR Ic host Ar hostname
+Set the host to which future queries will be sent.
+Hostname may
+be either a host name or a numeric address.
+.TP
+.BR Ic hostnames Op Cm yes | Cm no
+If
+.Cm yes
+is specified, host names are printed in
+information displays.
+If
+.Cm no
+is specified, numeric
+addresses are printed instead.
+The default is
+.Cm yes ,
+unless
+modified using the command line
+n
+switch.
+.TP
+.BR Ic keyid Ar keyid
+This command allows the specification of a key number to be
+used to authenticate configuration requests.
+This must correspond
+to a key number the server has been configured to use for this
+purpose.
+.TP
+.BR Ic quit
+Exit
+.Nm .
+.TP
+.BR Ic passwd
+This command prompts you to type in a password (which will not
+be echoed) which will be used to authenticate configuration
+requests.
+The password must correspond to the key configured for
+use by the NTP server for this purpose if such requests are to be
+successful.
+.TP
+.BR Ic timeout Ar milliseconds
+Specify a timeout period for responses to server queries.
+The
+default is about 8000 milliseconds.
+Note that since
+.Nm
+retries each query once after a timeout, the total waiting time for
+a timeout will be twice the timeout value set.
+.SS "Control Message Commands"
+Query commands result in NTP mode 7 packets containing requests for
+information being sent to the server.
+These are read-only commands
+in that they make no modification of the server configuration
+state.
+.TP
+.BR Ic listpeers
+Obtains and prints a brief list of the peers for which the
+server is maintaining state.
+These should include all configured
+peer associations as well as those peers whose stratum is such that
+they are considered by the server to be possible future
+synchronization candidates.
+.TP
+.BR Ic peers
+Obtains a list of peers for which the server is maintaining
+state, along with a summary of that state.
+Summary information
+includes the address of the remote peer, the local interface
+address (0.0.0.0 if a local address has yet to be determined), the
+stratum of the remote peer (a stratum of 16 indicates the remote
+peer is unsynchronized), the polling interval, in seconds, the
+reachability register, in octal, and the current estimated delay,
+offset and dispersion of the peer, all in seconds.
+.PP
+The character in the left margin indicates the mode this peer
+entry is operating in.
+A
+.Ql \&+
+denotes symmetric active, a
+.Ql \&-
+indicates symmetric passive, a
+.Ql \&=
+means the
+remote server is being polled in client mode, a
+.Ql \&^
+indicates that the server is broadcasting to this address, a
+.Ql \&~
+denotes that the remote peer is sending broadcasts and a
+.Ql \&~
+denotes that the remote peer is sending broadcasts and a
+.Ql \&*
+marks the peer the server is currently synchronizing
+to.
+.PP
+The contents of the host field may be one of four forms.
+It may
+be a host name, an IP address, a reference clock implementation
+name with its parameter or
+.Fn REFCLK "implementation_number" "parameter" .
+On
+.Ic hostnames
+.Cm no
+only IP-addresses
+will be displayed.
+.TP
+.BR Ic dmpeers
+A slightly different peer summary list.
+Identical to the output
+of the
+.Ic peers
+command, except for the character in the
+leftmost column.
+Characters only appear beside peers which were
+included in the final stage of the clock selection algorithm.
+A
+.Ql \&.
+indicates that this peer was cast off in the falseticker
+detection, while a
+.Ql \&+
+indicates that the peer made it
+through.
+A
+.Ql \&*
+denotes the peer the server is currently
+synchronizing with.
+.TP
+.BR Ic showpeer Ar peer_address Oo Ar ... Oc
+Shows a detailed display of the current peer variables for one
+or more peers.
+Most of these values are described in the NTP
+Version 2 specification.
+.TP
+.BR Ic pstats Ar peer_address Oo Ar ... Oc
+Show per-peer statistic counters associated with the specified
+peer(s).
+.TP
+.BR Ic clockinfo Ar clock_peer_address Oo Ar ... Oc
+Obtain and print information concerning a peer clock.
+The
+values obtained provide information on the setting of fudge factors
+and other clock performance information.
+.TP
+.BR Ic kerninfo
+Obtain and print kernel phase-lock loop operating parameters.
+This information is available only if the kernel has been specially
+modified for a precision timekeeping function.
+.TP
+.BR Ic loopinfo Op Cm oneline | Cm multiline
+Print the values of selected loop filter variables.
+The loop
+filter is the part of NTP which deals with adjusting the local
+system clock.
+The
+.Sq offset
+is the last offset given to the
+loop filter by the packet processing code.
+The
+.Sq frequency
+is the frequency error of the local clock in parts-per-million
+(ppm).
+The
+.Sq time_const
+controls the stiffness of the
+phase-lock loop and thus the speed at which it can adapt to
+oscillator drift.
+The
+.Sq watchdog timer
+value is the number
+of seconds which have elapsed since the last sample offset was
+given to the loop filter.
+The
+.Cm oneline
+and
+.Cm multiline
+options specify the format in which this
+information is to be printed, with
+.Cm multiline
+as the
+default.
+.TP
+.BR Ic sysinfo
+Print a variety of system state variables, i.e., state related
+to the local server.
+All except the last four lines are described
+in the NTP Version 3 specification, RFC-1305.
+.PP
+The
+.Sq system flags
+show various system flags, some of
+which can be set and cleared by the
+.Ic enable
+and
+.Ic disable
+configuration commands, respectively.
+These are
+the
+.Cm auth ,
+.Cm bclient ,
+.Cm monitor ,
+.Cm pll ,
+.Cm pps
+and
+.Cm stats
+flags.
+See the
+.Xr ntpd 8
+documentation for the meaning of these flags.
+There
+are two additional flags which are read only, the
+.Cm kernel_pll
+and
+.Cm kernel_pps .
+These flags indicate
+the synchronization status when the precision time kernel
+modifications are in use.
+The
+.Sq kernel_pll
+indicates that
+the local clock is being disciplined by the kernel, while the
+.Sq kernel_pps
+indicates the kernel discipline is provided by the PPS
+signal.
+.PP
+The
+.Sq stability
+is the residual frequency error remaining
+after the system frequency correction is applied and is intended for
+maintenance and debugging.
+In most architectures, this value will
+initially decrease from as high as 500 ppm to a nominal value in
+the range .01 to 0.1 ppm.
+If it remains high for some time after
+starting the daemon, something may be wrong with the local clock,
+or the value of the kernel variable
+.Va kern.clockrate.tick
+may be
+incorrect.
+.PP
+The
+.Sq broadcastdelay
+shows the default broadcast delay,
+as set by the
+.Ic broadcastdelay
+configuration command.
+.PP
+The
+.Sq authdelay
+shows the default authentication delay,
+as set by the
+.Ic authdelay
+configuration command.
+.TP
+.BR Ic sysstats
+Print statistics counters maintained in the protocol
+module.
+.TP
+.BR Ic memstats
+Print statistics counters related to memory allocation
+code.
+.TP
+.BR Ic iostats
+Print statistics counters maintained in the input-output
+module.
+.TP
+.BR Ic timerstats
+Print statistics counters maintained in the timer/event queue
+support code.
+.TP
+.BR Ic reslist
+Obtain and print the server's restriction list.
+This list is
+(usually) printed in sorted order and may help to understand how
+the restrictions are applied.
+.TP
+.BR Ic monlist Op Ar version
+Obtain and print traffic counts collected and maintained by the
+monitor facility.
+The version number should not normally need to be
+specified.
+.TP
+.BR Ic clkbug Ar clock_peer_address Oo Ar ... Oc
+Obtain debugging information for a reference clock driver.
+This
+information is provided only by some clock drivers and is mostly
+undecodable without a copy of the driver source in hand.
+.SS "Runtime Configuration Requests"
+All requests which cause state changes in the server are
+authenticated by the server using a configured NTP key (the
+facility can also be disabled by the server by not configuring a
+key).
+The key number and the corresponding key must also be made
+known to
+.B .
+This can be done using the
+.Ic keyid
+and
+.Ic passwd
+commands, the latter of which will prompt at the terminal for a
+password to use as the encryption key.
+You will also be prompted
+automatically for both the key number and password the first time a
+command which would result in an authenticated request to the
+server is given.
+Authentication not only provides verification that
+the requester has permission to make such changes, but also gives
+an extra degree of protection again transmission errors.
+.PP
+Authenticated requests always include a timestamp in the packet
+data, which is included in the computation of the authentication
+code.
+This timestamp is compared by the server to its receive time
+stamp.
+If they differ by more than a small amount the request is
+rejected.
+This is done for two reasons.
+First, it makes simple
+replay attacks on the server, by someone who might be able to
+overhear traffic on your LAN, much more difficult.
+Second, it makes
+it more difficult to request configuration changes to your server
+from topologically remote hosts.
+While the reconfiguration facility
+will work well with a server on the local host, and may work
+adequately between time-synchronized hosts on the same LAN, it will
+work very poorly for more distant hosts.
+As such, if reasonable
+passwords are chosen, care is taken in the distribution and
+protection of keys and appropriate source address restrictions are
+applied, the run time reconfiguration facility should provide an
+adequate level of security.
+.PP
+The following commands all make authenticated requests.
+.TP
+.BR Xo Ic addpeer Ar peer_address
+[ "\fIkeyid\fR" ]
+[ "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+.Xc
+Add a configured peer association at the given address and
+operating in symmetric active mode.
+Note that an existing
+association with the same peer may be deleted when this command is
+executed, or may simply be converted to conform to the new
+configuration, as appropriate.
+If the optional
+\fIkeyid\fR
+is a
+nonzero integer, all outgoing packets to the remote server will
+have an authentication field attached encrypted with this key.
+If
+the value is 0 (or not given) no authentication will be done.
+The
+\fIversion\fR
+can be 1, 2 or 3 and defaults to 3.
+The
+.Cm prefer
+keyword indicates a preferred peer (and thus will
+be used primarily for clock synchronisation if possible).
+The
+preferred peer also determines the validity of the PPS signal - if
+the preferred peer is suitable for synchronisation so is the PPS
+signal.
+.TP
+.BR Xo Ic addserver Ar peer_address
+[ "\fIkeyid\fR" ]
+[ "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+.Xc
+Identical to the addpeer command, except that the operating
+mode is client.
+.TP
+.BR Xo Ic broadcast Ar peer_address
+[ "\fIkeyid\fR" ]
+[ "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+.Xc
+Identical to the addpeer command, except that the operating
+mode is broadcast.
+In this case a valid key identifier and key are
+required.
+The
+\fIpeer_address\fR
+parameter can be the broadcast
+address of the local network or a multicast group address assigned
+to NTP.
+If a multicast address, a multicast-capable kernel is
+required.
+.TP
+.BR Ic unconfig Ar peer_address Oo Ar ... Oc
+This command causes the configured bit to be removed from the
+specified peer(s).
+In many cases this will cause the peer
+association to be deleted.
+When appropriate, however, the
+association may persist in an unconfigured mode if the remote peer
+is willing to continue on in this fashion.
+.TP
+.BR Xo Ic fudge Ar peer_address
+[ "\fItime1\fR" ]
+[ "\fItime2\fR" ]
+[ "\fIstratum\fR" ]
+[ "\fIrefid\fR" ]
+.Xc
+This command provides a way to set certain data for a reference
+clock.
+See the source listing for further information.
+.TP
+.BR Xo Ic enable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+.TP
+.BR Xo Ic disable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+These commands operate in the same way as the
+.Ic enable
+and
+.Ic disable
+configuration file commands of
+.Xr ntpd 8 .
+.in +4
+.ti -4
+.IR Cm auth
+Enables the server to synchronize with unconfigured peers only
+if the peer has been correctly authenticated using either public key
+or private key cryptography.
+The default for this flag is enable.
+.ti -4
+.IR Cm bclient
+Enables the server to listen for a message from a broadcast or
+multicast server, as in the multicastclient command with
+default address.
+The default for this flag is disable.
+.ti -4
+.IR Cm calibrate
+Enables the calibrate feature for reference clocks.
+The default for this flag is disable.
+.ti -4
+.IR Cm kernel
+Enables the kernel time discipline, if available.
+The default for this flag is enable if support is available, otherwise disable.
+.ti -4
+.IR Cm monitor
+Enables the monitoring facility.
+See the
+.Xr ntpdc 8 .
+program and the monlist command or further information.
+The default for this flag is enable.
+.ti -4
+.IR Cm ntp
+Enables time and frequency discipline.
+In effect, this switch opens and closes the feedback loop,
+which is useful for testing.
+The default for this flag is enable.
+.ti -4
+.IR Cm pps
+Enables the pulse-per-second (PPS) signal when frequency
+and time is disciplined by the precision time kernel modifications.
+See the
+.Qq A Kernel Model for Precision Timekeeping
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page for further information.
+The default for this flag is disable.
+.ti -4
+.IR Cm stats
+Enables the statistics facility.
+See the
+.Sx Monitoring Options
+section of
+.Xr ntp.conf 5
+for further information.
+The default for this flag is disable.
+.in -4
+.TP
+.BR Xo Ic restrict Ar address Ar mask
+\fIflag Oo Ar ... Oc\fR
+.Xc
+This command operates in the same way as the
+.Ic restrict
+configuration file commands of
+.Xr ntpd 8 .
+.TP
+.BR Xo Ic unrestrict Ar address Ar mask
+\fIflag Oo Ar ... Oc\fR
+.Xc
+Unrestrict the matching entry from the restrict list.
+.TP
+.BR Xo Ic delrestrict Ar address Ar mask
+[ "\fIntpport\fR" ]
+.Xc
+Delete the matching entry from the restrict list.
+.TP
+.BR Ic readkeys
+Causes the current set of authentication keys to be purged and
+a new set to be obtained by rereading the keys file (which must
+have been specified in the
+.Xr ntpd 8
+configuration file).
+This
+allows encryption keys to be changed without restarting the
+server.
+.TP
+.BR Ic trustedkey Ar keyid Oo Ar ... Oc
+.TP
+.BR Ic untrustedkey Ar keyid Oo Ar ... Oc
+These commands operate in the same way as the
+.Ic trustedkey
+and
+.Ic untrustedkey
+configuration file
+commands of
+.Xr ntpd 8 .
+.TP
+.BR Ic authinfo
+Returns information concerning the authentication module,
+including known keys and counts of encryptions and decryptions
+which have been done.
+.TP
+.BR Ic traps
+Display the traps set in the server.
+See the source listing for
+further information.
+.TP
+.BR Xo Ic addtrap Ar address
+[ "\fIport\fR" ]
+[ "\fIinterface\fR" ]
+.Xc
+Set a trap for asynchronous messages.
+See the source listing
+for further information.
+.TP
+.BR Xo Ic clrtrap Ar address
+[ "\fIport\fR" ]
+[ "\fIinterface\fR" ]
+.Xc
+Clear a trap for asynchronous messages.
+See the source listing
+for further information.
+.TP
+.BR Ic reset
+Clear the statistics counters in various modules of the server.
+See the source listing for further information.
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH "FILES"
libopts had an internal operational error. Please report
it to autogen-users@lists.sourceforge.net. Thank you.
.SH "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpd 8
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 3)
+.%O RFC1305
+.Re
.SH AUTHORS
+The formatting directives in this document came from FreeBSD.
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The
+.B
+utility is a crude hack.
+Much of the information it shows is
+deadly boring and could only be loved by its implementer.
+The
+program was designed so that new (and temporary) features were easy
+to hack in, at great expense to the program's ease of use.
+Despite
+this, the program is occasionally useful.
+.PP
+Please report bugs to http://bugs.ntp.org .Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH "NOTES"
This manual page was \fIAutoGen\fP-erated from the \fBntpdc\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTPDC 1ntpdcmdoc User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntpdc-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:18 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:58 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpdc-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
[ host ...]
.Pp
.Sh DESCRIPTION
+.Nm
+is a utility program used to query
+.Xr ntpd 8
+about its
+current state and to request changes in that state.
+It uses NTP mode 7 control message formats described in the source code.
+The program may
+be run either in interactive mode or controlled using command line
+arguments.
+Extensive state and statistics information is available
+through the
+.Nm
+interface.
+In addition, nearly all the
+configuration options which can be specified at startup using
+ntpd's configuration file may also be specified at run time using
+.Nm .
.Sh "OPTIONS"
.Bl -tag
.It \-4 ", " -\-ipv4
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.Sh USAGE
+If one or more request options are included on the command line
+when
+.Nm
+is executed, each of the requests will be sent
+to the NTP servers running on each of the hosts given as command
+line arguments, or on localhost by default.
+If no request options
+are given,
+.Nm
+will attempt to read commands from the
+standard input and execute these on the NTP server running on the
+first host given on the command line, again defaulting to localhost
+when no other host is specified.
+The
+.Nm
+utility will prompt for
+commands if the standard input is a terminal device.
+.Pp
+The
+.Nm
+utility uses NTP mode 7 packets to communicate with the
+NTP server, and hence can be used to query any compatible server on
+the network which permits it.
+Note that since NTP is a UDP protocol
+this communication will be somewhat unreliable, especially over
+large distances in terms of network topology.
+The
+.Nm
+utility makes
+no attempt to retransmit requests, and will time requests out if
+the remote host is not heard from within a suitable timeout
+time.
+.Pp
+The operation of
+.Nm
+are specific to the particular
+implementation of the
+.Xr ntpd 8
+daemon and can be expected to
+work only with this and maybe some previous versions of the daemon.
+Requests from a remote
+.Nm
+utility which affect the
+state of the local server must be authenticated, which requires
+both the remote program and local server share a common key and key
+identifier.
+.Pp
+Note that in contexts where a host name is expected, a
+.Fl 4
+qualifier preceding the host name forces DNS resolution to the IPv4 namespace,
+while a
+.Fl 6
+qualifier forces DNS resolution to the IPv6 namespace.
+Specifying a command line option other than
+.Fl i
+or
+.Fl n
+will cause the specified query (queries) to be sent to
+the indicated host(s) immediately.
+Otherwise,
+.Nm
+will
+attempt to read interactive format commands from the standard
+input.
+.Ss "Interactive Commands"
+Interactive format commands consist of a keyword followed by zero
+to four arguments.
+Only enough characters of the full keyword to
+uniquely identify the command need be typed.
+The output of a
+command is normally sent to the standard output, but optionally the
+output of individual commands may be sent to a file by appending a
+.Ql \&> ,
+followed by a file name, to the command line.
+.Pp
+A number of interactive format commands are executed entirely
+within the
+.Nm
+utility itself and do not result in NTP
+mode 7 requests being sent to a server.
+These are described
+following.
+.Bl -tag -width indent
+.It Ic \&? Ar command_keyword
+.It Ic help Ar command_keyword
+A
+.Sq Ic \&?
+will print a list of all the command
+keywords known to this incarnation of
+.Nm .
+A
+.Sq Ic \&?
+followed by a command keyword will print function and usage
+information about the command.
+This command is probably a better
+source of information about
+.Xr ntpq 8
+than this manual
+page.
+.It Ic delay Ar milliseconds
+Specify a time interval to be added to timestamps included in
+requests which require authentication.
+This is used to enable
+(unreliable) server reconfiguration over long delay network paths
+or between machines whose clocks are unsynchronized.
+Actually the
+server does not now require timestamps in authenticated requests,
+so this command may be obsolete.
+.It Ic host Ar hostname
+Set the host to which future queries will be sent.
+Hostname may
+be either a host name or a numeric address.
+.It Ic hostnames Op Cm yes | Cm no
+If
+.Cm yes
+is specified, host names are printed in
+information displays.
+If
+.Cm no
+is specified, numeric
+addresses are printed instead.
+The default is
+.Cm yes ,
+unless
+modified using the command line
+.Fl n
+switch.
+.It Ic keyid Ar keyid
+This command allows the specification of a key number to be
+used to authenticate configuration requests.
+This must correspond
+to a key number the server has been configured to use for this
+purpose.
+.It Ic quit
+Exit
+.Nm .
+.It Ic passwd
+This command prompts you to type in a password (which will not
+be echoed) which will be used to authenticate configuration
+requests.
+The password must correspond to the key configured for
+use by the NTP server for this purpose if such requests are to be
+successful.
+.It Ic timeout Ar milliseconds
+Specify a timeout period for responses to server queries.
+The
+default is about 8000 milliseconds.
+Note that since
+.Nm
+retries each query once after a timeout, the total waiting time for
+a timeout will be twice the timeout value set.
+.El
+.Ss "Control Message Commands"
+Query commands result in NTP mode 7 packets containing requests for
+information being sent to the server.
+These are read-only commands
+in that they make no modification of the server configuration
+state.
+.Bl -tag -width indent
+.It Ic listpeers
+Obtains and prints a brief list of the peers for which the
+server is maintaining state.
+These should include all configured
+peer associations as well as those peers whose stratum is such that
+they are considered by the server to be possible future
+synchronization candidates.
+.It Ic peers
+Obtains a list of peers for which the server is maintaining
+state, along with a summary of that state.
+Summary information
+includes the address of the remote peer, the local interface
+address (0.0.0.0 if a local address has yet to be determined), the
+stratum of the remote peer (a stratum of 16 indicates the remote
+peer is unsynchronized), the polling interval, in seconds, the
+reachability register, in octal, and the current estimated delay,
+offset and dispersion of the peer, all in seconds.
+.Pp
+The character in the left margin indicates the mode this peer
+entry is operating in.
+A
+.Ql \&+
+denotes symmetric active, a
+.Ql \&-
+indicates symmetric passive, a
+.Ql \&=
+means the
+remote server is being polled in client mode, a
+.Ql \&^
+indicates that the server is broadcasting to this address, a
+.Ql \&~
+denotes that the remote peer is sending broadcasts and a
+.Ql \&~
+denotes that the remote peer is sending broadcasts and a
+.Ql \&*
+marks the peer the server is currently synchronizing
+to.
+.Pp
+The contents of the host field may be one of four forms.
+It may
+be a host name, an IP address, a reference clock implementation
+name with its parameter or
+.Fn REFCLK "implementation_number" "parameter" .
+On
+.Ic hostnames
+.Cm no
+only IP-addresses
+will be displayed.
+.It Ic dmpeers
+A slightly different peer summary list.
+Identical to the output
+of the
+.Ic peers
+command, except for the character in the
+leftmost column.
+Characters only appear beside peers which were
+included in the final stage of the clock selection algorithm.
+A
+.Ql \&.
+indicates that this peer was cast off in the falseticker
+detection, while a
+.Ql \&+
+indicates that the peer made it
+through.
+A
+.Ql \&*
+denotes the peer the server is currently
+synchronizing with.
+.It Ic showpeer Ar peer_address Oo Ar ... Oc
+Shows a detailed display of the current peer variables for one
+or more peers.
+Most of these values are described in the NTP
+Version 2 specification.
+.It Ic pstats Ar peer_address Oo Ar ... Oc
+Show per-peer statistic counters associated with the specified
+peer(s).
+.It Ic clockinfo Ar clock_peer_address Oo Ar ... Oc
+Obtain and print information concerning a peer clock.
+The
+values obtained provide information on the setting of fudge factors
+and other clock performance information.
+.It Ic kerninfo
+Obtain and print kernel phase-lock loop operating parameters.
+This information is available only if the kernel has been specially
+modified for a precision timekeeping function.
+.It Ic loopinfo Op Cm oneline | Cm multiline
+Print the values of selected loop filter variables.
+The loop
+filter is the part of NTP which deals with adjusting the local
+system clock.
+The
+.Sq offset
+is the last offset given to the
+loop filter by the packet processing code.
+The
+.Sq frequency
+is the frequency error of the local clock in parts-per-million
+(ppm).
+The
+.Sq time_const
+controls the stiffness of the
+phase-lock loop and thus the speed at which it can adapt to
+oscillator drift.
+The
+.Sq watchdog timer
+value is the number
+of seconds which have elapsed since the last sample offset was
+given to the loop filter.
+The
+.Cm oneline
+and
+.Cm multiline
+options specify the format in which this
+information is to be printed, with
+.Cm multiline
+as the
+default.
+.It Ic sysinfo
+Print a variety of system state variables, i.e., state related
+to the local server.
+All except the last four lines are described
+in the NTP Version 3 specification, RFC-1305.
+.Pp
+The
+.Sq system flags
+show various system flags, some of
+which can be set and cleared by the
+.Ic enable
+and
+.Ic disable
+configuration commands, respectively.
+These are
+the
+.Cm auth ,
+.Cm bclient ,
+.Cm monitor ,
+.Cm pll ,
+.Cm pps
+and
+.Cm stats
+flags.
+See the
+.Xr ntpd 8
+documentation for the meaning of these flags.
+There
+are two additional flags which are read only, the
+.Cm kernel_pll
+and
+.Cm kernel_pps .
+These flags indicate
+the synchronization status when the precision time kernel
+modifications are in use.
+The
+.Sq kernel_pll
+indicates that
+the local clock is being disciplined by the kernel, while the
+.Sq kernel_pps
+indicates the kernel discipline is provided by the PPS
+signal.
+.Pp
+The
+.Sq stability
+is the residual frequency error remaining
+after the system frequency correction is applied and is intended for
+maintenance and debugging.
+In most architectures, this value will
+initially decrease from as high as 500 ppm to a nominal value in
+the range .01 to 0.1 ppm.
+If it remains high for some time after
+starting the daemon, something may be wrong with the local clock,
+or the value of the kernel variable
+.Va kern.clockrate.tick
+may be
+incorrect.
+.Pp
+The
+.Sq broadcastdelay
+shows the default broadcast delay,
+as set by the
+.Ic broadcastdelay
+configuration command.
+.Pp
+The
+.Sq authdelay
+shows the default authentication delay,
+as set by the
+.Ic authdelay
+configuration command.
+.It Ic sysstats
+Print statistics counters maintained in the protocol
+module.
+.It Ic memstats
+Print statistics counters related to memory allocation
+code.
+.It Ic iostats
+Print statistics counters maintained in the input-output
+module.
+.It Ic timerstats
+Print statistics counters maintained in the timer/event queue
+support code.
+.It Ic reslist
+Obtain and print the server's restriction list.
+This list is
+(usually) printed in sorted order and may help to understand how
+the restrictions are applied.
+.It Ic monlist Op Ar version
+Obtain and print traffic counts collected and maintained by the
+monitor facility.
+The version number should not normally need to be
+specified.
+.It Ic clkbug Ar clock_peer_address Oo Ar ... Oc
+Obtain debugging information for a reference clock driver.
+This
+information is provided only by some clock drivers and is mostly
+undecodable without a copy of the driver source in hand.
+.El
+.Ss "Runtime Configuration Requests"
+All requests which cause state changes in the server are
+authenticated by the server using a configured NTP key (the
+facility can also be disabled by the server by not configuring a
+key).
+The key number and the corresponding key must also be made
+known to
+.Nm .
+This can be done using the
+.Ic keyid
+and
+.Ic passwd
+commands, the latter of which will prompt at the terminal for a
+password to use as the encryption key.
+You will also be prompted
+automatically for both the key number and password the first time a
+command which would result in an authenticated request to the
+server is given.
+Authentication not only provides verification that
+the requester has permission to make such changes, but also gives
+an extra degree of protection again transmission errors.
+.Pp
+Authenticated requests always include a timestamp in the packet
+data, which is included in the computation of the authentication
+code.
+This timestamp is compared by the server to its receive time
+stamp.
+If they differ by more than a small amount the request is
+rejected.
+This is done for two reasons.
+First, it makes simple
+replay attacks on the server, by someone who might be able to
+overhear traffic on your LAN, much more difficult.
+Second, it makes
+it more difficult to request configuration changes to your server
+from topologically remote hosts.
+While the reconfiguration facility
+will work well with a server on the local host, and may work
+adequately between time-synchronized hosts on the same LAN, it will
+work very poorly for more distant hosts.
+As such, if reasonable
+passwords are chosen, care is taken in the distribution and
+protection of keys and appropriate source address restrictions are
+applied, the run time reconfiguration facility should provide an
+adequate level of security.
+.Pp
+The following commands all make authenticated requests.
+.Bl -tag -width indent
+.It Xo Ic addpeer Ar peer_address
+.Op Ar keyid
+.Op Ar version
+.Op Cm prefer
+.Xc
+Add a configured peer association at the given address and
+operating in symmetric active mode.
+Note that an existing
+association with the same peer may be deleted when this command is
+executed, or may simply be converted to conform to the new
+configuration, as appropriate.
+If the optional
+.Ar keyid
+is a
+nonzero integer, all outgoing packets to the remote server will
+have an authentication field attached encrypted with this key.
+If
+the value is 0 (or not given) no authentication will be done.
+The
+.Ar version
+can be 1, 2 or 3 and defaults to 3.
+The
+.Cm prefer
+keyword indicates a preferred peer (and thus will
+be used primarily for clock synchronisation if possible).
+The
+preferred peer also determines the validity of the PPS signal - if
+the preferred peer is suitable for synchronisation so is the PPS
+signal.
+.It Xo Ic addserver Ar peer_address
+.Op Ar keyid
+.Op Ar version
+.Op Cm prefer
+.Xc
+Identical to the addpeer command, except that the operating
+mode is client.
+.It Xo Ic broadcast Ar peer_address
+.Op Ar keyid
+.Op Ar version
+.Op Cm prefer
+.Xc
+Identical to the addpeer command, except that the operating
+mode is broadcast.
+In this case a valid key identifier and key are
+required.
+The
+.Ar peer_address
+parameter can be the broadcast
+address of the local network or a multicast group address assigned
+to NTP.
+If a multicast address, a multicast-capable kernel is
+required.
+.It Ic unconfig Ar peer_address Oo Ar ... Oc
+This command causes the configured bit to be removed from the
+specified peer(s).
+In many cases this will cause the peer
+association to be deleted.
+When appropriate, however, the
+association may persist in an unconfigured mode if the remote peer
+is willing to continue on in this fashion.
+.It Xo Ic fudge Ar peer_address
+.Op Cm time1
+.Op Cm time2
+.Op Ar stratum
+.Op Ar refid
+.Xc
+This command provides a way to set certain data for a reference
+clock.
+See the source listing for further information.
+.It Xo Ic enable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+.It Xo Ic disable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+These commands operate in the same way as the
+.Ic enable
+and
+.Ic disable
+configuration file commands of
+.Xr ntpd 8 .
+.Bl -tag -width indent
+.It Cm auth
+Enables the server to synchronize with unconfigured peers only
+if the peer has been correctly authenticated using either public key
+or private key cryptography.
+The default for this flag is enable.
+.It Cm bclient
+Enables the server to listen for a message from a broadcast or
+multicast server, as in the multicastclient command with
+default address.
+The default for this flag is disable.
+.It Cm calibrate
+Enables the calibrate feature for reference clocks.
+The default for this flag is disable.
+.It Cm kernel
+Enables the kernel time discipline, if available.
+The default for this flag is enable if support is available, otherwise disable.
+.It Cm monitor
+Enables the monitoring facility.
+See the
+.Xr ntpdc 8 .
+program and the monlist command or further information.
+The default for this flag is enable.
+.It Cm ntp
+Enables time and frequency discipline.
+In effect, this switch opens and closes the feedback loop,
+which is useful for testing.
+The default for this flag is enable.
+.It Cm pps
+Enables the pulse-per-second (PPS) signal when frequency
+and time is disciplined by the precision time kernel modifications.
+See the
+.Qq A Kernel Model for Precision Timekeeping
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page for further information.
+The default for this flag is disable.
+.It Cm stats
+Enables the statistics facility.
+See the
+.Sx Monitoring Options
+section of
+.Xr ntp.conf 5
+for further information.
+The default for this flag is disable.
+.El
+.It Xo Ic restrict Ar address Ar mask
+.Ar flag Oo Ar ... Oc
+.Xc
+This command operates in the same way as the
+.Ic restrict
+configuration file commands of
+.Xr ntpd 8 .
+.It Xo Ic unrestrict Ar address Ar mask
+.Ar flag Oo Ar ... Oc
+.Xc
+Unrestrict the matching entry from the restrict list.
+.It Xo Ic delrestrict Ar address Ar mask
+.Op Cm ntpport
+.Xc
+Delete the matching entry from the restrict list.
+.It Ic readkeys
+Causes the current set of authentication keys to be purged and
+a new set to be obtained by rereading the keys file (which must
+have been specified in the
+.Xr ntpd 8
+configuration file).
+This
+allows encryption keys to be changed without restarting the
+server.
+.It Ic trustedkey Ar keyid Oo Ar ... Oc
+.It Ic untrustedkey Ar keyid Oo Ar ... Oc
+These commands operate in the same way as the
+.Ic trustedkey
+and
+.Ic untrustedkey
+configuration file
+commands of
+.Xr ntpd 8 .
+.It Ic authinfo
+Returns information concerning the authentication module,
+including known keys and counts of encryptions and decryptions
+which have been done.
+.It Ic traps
+Display the traps set in the server.
+See the source listing for
+further information.
+.It Xo Ic addtrap Ar address
+.Op Ar port
+.Op Ar interface
+.Xc
+Set a trap for asynchronous messages.
+See the source listing
+for further information.
+.It Xo Ic clrtrap Ar address
+.Op Ar port
+.Op Ar interface
+.Xc
+Clear a trap for asynchronous messages.
+See the source listing
+for further information.
+.It Ic reset
+Clear the statistics counters in various modules of the server.
+See the source listing for further information.
+.El
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh "FILES"
it to autogen-users@lists.sourceforge.net. Thank you.
.El
.Sh "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpd 8
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 3)
+.%O RFC1305
+.Re
.Sh AUTHORS
+The formatting directives in this document came from FreeBSD.
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The
+.Nm
+utility is a crude hack.
+Much of the information it shows is
+deadly boring and could only be loved by its implementer.
+The
+program was designed so that new (and temporary) features were easy
+to hack in, at great expense to the program's ease of use.
+Despite
+this, the program is occasionally useful.
+.Pp
+Please report bugs to http://bugs.ntp.org .Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh "NOTES"
This manual page was \fIAutoGen\fP-erated from the \fBntpdc\fP
option definitions.
clock. Run as root, it can correct the system clock to this offset as
well. It can be run as an interactive command or from a cron job.
- <p>This document applies to version 4.2.7p343 of <code>ntpdc</code>.
+ <p>This document applies to version 4.2.7p344 of <code>ntpdc</code>.
<p>The program implements the SNTP protocol as defined by RFC 5905, the NTPv4
IETF specification.
used to select the program, defaulting to <span class="file">more</span>. Both will exit
with a status code of 0.
-<pre class="example">ntpdc - vendor-specific NTPD control program - Ver. 4.2.7p343
+<pre class="example">ntpdc - vendor-specific NTPD control program - Ver. 4.2.7p344
USAGE: ntpdc [ -<flag> [<val>] | --<name>[{=| }<val>] ]... [ host ...]
Flg Arg Option-Name Description
-4 no ipv4 Force IPv4 DNS name resolution
identifier.
<p>Note that in contexts where a host name is expected, a
-<code>-4</code> qualifier preceding the host name forces DNS resolution to the IPv4 namespace,
+<code>-4</code>
+qualifier preceding the host name forces DNS resolution to the IPv4 namespace,
while a
-<code>-6</code> qualifier forces DNS resolution to the IPv6 namespace.
+<code>-6</code>
+qualifier forces DNS resolution to the IPv6 namespace.
Specifying a command line option other than
-<code>-i</code> or
-<code>-n</code> will cause the specified query (queries) to be sent to
+<code>-i</code>
+or
+<code>-n</code>
+will cause the specified query (queries) to be sent to
the indicated host(s) immediately.
Otherwise,
<code>ntpdc</code>
<h3 class="section">Interactive Commands</h3>
-<p>Interactive Commands
-Interactive format commands consist of a keyword followed by zero
+<p>Interactive format commands consist of a keyword followed by zero
to four arguments.
Only enough characters of the full keyword to
uniquely identify the command need be typed.
The output of a
command is normally sent to the standard output, but optionally the
output of individual commands may be sent to a file by appending a
-\&>,
+>,
followed by a file name, to the command line.
<p>A number of interactive format commands are executed entirely
These are described
following.
<dl>
-<dt><span class="samp">Ic</span><br><dt><span class="samp">Ic</span><dd>A
-Ic \&?
+<dt><code>?</code> <kbd>command_keyword</kbd><br><dt><code>help</code> <kbd>command_keyword</kbd><dd>A
+<code>?</code>
will print a list of all the command
keywords known to this incarnation of
<code>ntpdc</code>.
A
-Ic \&?
+<code>?</code>
followed by a command keyword will print function and usage
information about the command.
This command is probably a better
<code>ntpq(8)</code>
than this manual
page.
-<br><dt><span class="samp">Ic</span><dd>Specify a time interval to be added to timestamps included in
+<br><dt><code>delay</code> <kbd>milliseconds</kbd><dd>Specify a time interval to be added to timestamps included in
requests which require authentication.
This is used to enable
(unreliable) server reconfiguration over long delay network paths
Actually the
server does not now require timestamps in authenticated requests,
so this command may be obsolete.
-<br><dt><span class="samp">Ic</span><dd>Set the host to which future queries will be sent.
+<br><dt><code>host</code> <kbd>hostname</kbd><dd>Set the host to which future queries will be sent.
Hostname may
be either a host name or a numeric address.
-<br><dt><span class="samp">Ic</span><dd>If
-<code>yes</code> is specified, host names are printed in
+<br><dt><code>hostnames</code> [<code>yes</code> | <code>Cm</code> <code>no</code>]<dd>If
+<code>yes</code>
+is specified, host names are printed in
information displays.
If
-<code>no</code> is specified, numeric
+<code>no</code>
+is specified, numeric
addresses are printed instead.
The default is
-<code>yes</code>, unless
+<code>yes</code>,
+unless
modified using the command line
-<code>-n</code> switch.
-<br><dt><span class="samp">Ic</span><dd>This command allows the specification of a key number to be
+<code>-n</code>
+switch.
+<br><dt><code>keyid</code> <kbd>keyid</kbd><dd>This command allows the specification of a key number to be
used to authenticate configuration requests.
This must correspond
to a key number the server has been configured to use for this
purpose.
-<br><dt><span class="samp">Ic</span><dd>Exit
+<br><dt><code>quit</code><dd>Exit
<code>ntpdc</code>.
-<br><dt><span class="samp">Ic</span><dd>This command prompts you to type in a password (which will not
+<br><dt><code>passwd</code><dd>This command prompts you to type in a password (which will not
be echoed) which will be used to authenticate configuration
requests.
The password must correspond to the key configured for
use by the NTP server for this purpose if such requests are to be
successful.
-<br><dt><span class="samp">Ic</span><dd>Specify a timeout period for responses to server queries.
+<br><dt><code>timeout</code> <kbd>milliseconds</kbd><dd>Specify a timeout period for responses to server queries.
The
default is about 8000 milliseconds.
Note that since
<h3 class="section">Control Message Commands</h3>
-<p>Control Message Commands
-Query commands result in NTP mode 7 packets containing requests for
+<p>Query commands result in NTP mode 7 packets containing requests for
information being sent to the server.
These are read-only commands
in that they make no modification of the server configuration
state.
<dl>
-<dt><span class="samp">Ic</span><dd>Obtains and prints a brief list of the peers for which the
+<dt><code>listpeers</code><dd>Obtains and prints a brief list of the peers for which the
server is maintaining state.
These should include all configured
peer associations as well as those peers whose stratum is such that
they are considered by the server to be possible future
synchronization candidates.
-<br><dt><span class="samp">Ic</span><dd>Obtains a list of peers for which the server is maintaining
+<br><dt><code>peers</code><dd>Obtains a list of peers for which the server is maintaining
state, along with a summary of that state.
Summary information
includes the address of the remote peer, the local interface
<p>The character in the left margin indicates the mode this peer
entry is operating in.
A
-\&+
++
denotes symmetric active, a
-\&-
+-
indicates symmetric passive, a
-\&=
+=
means the
remote server is being polled in client mode, a
-\&^
+^
indicates that the server is broadcasting to this address, a
-\&~
+~
denotes that the remote peer is sending broadcasts and a
-\&~
+~
denotes that the remote peer is sending broadcasts and a
-\&*
+*
marks the peer the server is currently synchronizing
to.
-.TH ntpdc @NTPDC_MS@ "02 Jan 2013" "4.2.7p343" "User Commands"
+.TH ntpdc @NTPDC_MS@ "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntpdc-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:12 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:52 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpdc-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntpdc
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..." [ host ...]
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..." " " "[ host ...]"
.PP
.SH DESCRIPTION
+.B
+is a utility program used to query
+.Xr ntpd 8
+about its
+current state and to request changes in that state.
+It uses NTP mode 7 control message formats described in the source code.
+The program may
+be run either in interactive mode or controlled using command line
+arguments.
+Extensive state and statistics information is available
+through the
+.B
+interface.
+In addition, nearly all the
+configuration options which can be specified at startup using
+ntpd's configuration file may also be specified at run time using
+.B .
.SH "OPTIONS"
.TP
.BR \-4 ", " -\-ipv4
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.SH USAGE
+If one or more request options are included on the command line
+when
+.B
+is executed, each of the requests will be sent
+to the NTP servers running on each of the hosts given as command
+line arguments, or on localhost by default.
+If no request options
+are given,
+.B
+will attempt to read commands from the
+standard input and execute these on the NTP server running on the
+first host given on the command line, again defaulting to localhost
+when no other host is specified.
+The
+.B
+utility will prompt for
+commands if the standard input is a terminal device.
+.PP
+The
+.B
+utility uses NTP mode 7 packets to communicate with the
+NTP server, and hence can be used to query any compatible server on
+the network which permits it.
+Note that since NTP is a UDP protocol
+this communication will be somewhat unreliable, especially over
+large distances in terms of network topology.
+The
+.B
+utility makes
+no attempt to retransmit requests, and will time requests out if
+the remote host is not heard from within a suitable timeout
+time.
+.PP
+The operation of
+.B
+are specific to the particular
+implementation of the
+.Xr ntpd 8
+daemon and can be expected to
+work only with this and maybe some previous versions of the daemon.
+Requests from a remote
+.B
+utility which affect the
+state of the local server must be authenticated, which requires
+both the remote program and local server share a common key and key
+identifier.
+.PP
+Note that in contexts where a host name is expected, a
+4
+qualifier preceding the host name forces DNS resolution to the IPv4 namespace,
+while a
+6
+qualifier forces DNS resolution to the IPv6 namespace.
+Specifying a command line option other than
+i
+or
+n
+will cause the specified query (queries) to be sent to
+the indicated host(s) immediately.
+Otherwise,
+.B
+will
+attempt to read interactive format commands from the standard
+input.
+.SS "Interactive Commands"
+Interactive format commands consist of a keyword followed by zero
+to four arguments.
+Only enough characters of the full keyword to
+uniquely identify the command need be typed.
+The output of a
+command is normally sent to the standard output, but optionally the
+output of individual commands may be sent to a file by appending a
+.Ql \&> ,
+followed by a file name, to the command line.
+.PP
+A number of interactive format commands are executed entirely
+within the
+.B
+utility itself and do not result in NTP
+mode 7 requests being sent to a server.
+These are described
+following.
+.TP
+.BR Ic \&? Ar command_keyword
+.TP
+.BR Ic help Ar command_keyword
+A
+.Sq Ic \&?
+will print a list of all the command
+keywords known to this incarnation of
+.Nm .
+A
+.Sq Ic \&?
+followed by a command keyword will print function and usage
+information about the command.
+This command is probably a better
+source of information about
+.Xr ntpq 8
+than this manual
+page.
+.TP
+.BR Ic delay Ar milliseconds
+Specify a time interval to be added to timestamps included in
+requests which require authentication.
+This is used to enable
+(unreliable) server reconfiguration over long delay network paths
+or between machines whose clocks are unsynchronized.
+Actually the
+server does not now require timestamps in authenticated requests,
+so this command may be obsolete.
+.TP
+.BR Ic host Ar hostname
+Set the host to which future queries will be sent.
+Hostname may
+be either a host name or a numeric address.
+.TP
+.BR Ic hostnames Op Cm yes | Cm no
+If
+.Cm yes
+is specified, host names are printed in
+information displays.
+If
+.Cm no
+is specified, numeric
+addresses are printed instead.
+The default is
+.Cm yes ,
+unless
+modified using the command line
+n
+switch.
+.TP
+.BR Ic keyid Ar keyid
+This command allows the specification of a key number to be
+used to authenticate configuration requests.
+This must correspond
+to a key number the server has been configured to use for this
+purpose.
+.TP
+.BR Ic quit
+Exit
+.Nm .
+.TP
+.BR Ic passwd
+This command prompts you to type in a password (which will not
+be echoed) which will be used to authenticate configuration
+requests.
+The password must correspond to the key configured for
+use by the NTP server for this purpose if such requests are to be
+successful.
+.TP
+.BR Ic timeout Ar milliseconds
+Specify a timeout period for responses to server queries.
+The
+default is about 8000 milliseconds.
+Note that since
+.Nm
+retries each query once after a timeout, the total waiting time for
+a timeout will be twice the timeout value set.
+.SS "Control Message Commands"
+Query commands result in NTP mode 7 packets containing requests for
+information being sent to the server.
+These are read-only commands
+in that they make no modification of the server configuration
+state.
+.TP
+.BR Ic listpeers
+Obtains and prints a brief list of the peers for which the
+server is maintaining state.
+These should include all configured
+peer associations as well as those peers whose stratum is such that
+they are considered by the server to be possible future
+synchronization candidates.
+.TP
+.BR Ic peers
+Obtains a list of peers for which the server is maintaining
+state, along with a summary of that state.
+Summary information
+includes the address of the remote peer, the local interface
+address (0.0.0.0 if a local address has yet to be determined), the
+stratum of the remote peer (a stratum of 16 indicates the remote
+peer is unsynchronized), the polling interval, in seconds, the
+reachability register, in octal, and the current estimated delay,
+offset and dispersion of the peer, all in seconds.
+.PP
+The character in the left margin indicates the mode this peer
+entry is operating in.
+A
+.Ql \&+
+denotes symmetric active, a
+.Ql \&-
+indicates symmetric passive, a
+.Ql \&=
+means the
+remote server is being polled in client mode, a
+.Ql \&^
+indicates that the server is broadcasting to this address, a
+.Ql \&~
+denotes that the remote peer is sending broadcasts and a
+.Ql \&~
+denotes that the remote peer is sending broadcasts and a
+.Ql \&*
+marks the peer the server is currently synchronizing
+to.
+.PP
+The contents of the host field may be one of four forms.
+It may
+be a host name, an IP address, a reference clock implementation
+name with its parameter or
+.Fn REFCLK "implementation_number" "parameter" .
+On
+.Ic hostnames
+.Cm no
+only IP-addresses
+will be displayed.
+.TP
+.BR Ic dmpeers
+A slightly different peer summary list.
+Identical to the output
+of the
+.Ic peers
+command, except for the character in the
+leftmost column.
+Characters only appear beside peers which were
+included in the final stage of the clock selection algorithm.
+A
+.Ql \&.
+indicates that this peer was cast off in the falseticker
+detection, while a
+.Ql \&+
+indicates that the peer made it
+through.
+A
+.Ql \&*
+denotes the peer the server is currently
+synchronizing with.
+.TP
+.BR Ic showpeer Ar peer_address Oo Ar ... Oc
+Shows a detailed display of the current peer variables for one
+or more peers.
+Most of these values are described in the NTP
+Version 2 specification.
+.TP
+.BR Ic pstats Ar peer_address Oo Ar ... Oc
+Show per-peer statistic counters associated with the specified
+peer(s).
+.TP
+.BR Ic clockinfo Ar clock_peer_address Oo Ar ... Oc
+Obtain and print information concerning a peer clock.
+The
+values obtained provide information on the setting of fudge factors
+and other clock performance information.
+.TP
+.BR Ic kerninfo
+Obtain and print kernel phase-lock loop operating parameters.
+This information is available only if the kernel has been specially
+modified for a precision timekeeping function.
+.TP
+.BR Ic loopinfo Op Cm oneline | Cm multiline
+Print the values of selected loop filter variables.
+The loop
+filter is the part of NTP which deals with adjusting the local
+system clock.
+The
+.Sq offset
+is the last offset given to the
+loop filter by the packet processing code.
+The
+.Sq frequency
+is the frequency error of the local clock in parts-per-million
+(ppm).
+The
+.Sq time_const
+controls the stiffness of the
+phase-lock loop and thus the speed at which it can adapt to
+oscillator drift.
+The
+.Sq watchdog timer
+value is the number
+of seconds which have elapsed since the last sample offset was
+given to the loop filter.
+The
+.Cm oneline
+and
+.Cm multiline
+options specify the format in which this
+information is to be printed, with
+.Cm multiline
+as the
+default.
+.TP
+.BR Ic sysinfo
+Print a variety of system state variables, i.e., state related
+to the local server.
+All except the last four lines are described
+in the NTP Version 3 specification, RFC-1305.
+.PP
+The
+.Sq system flags
+show various system flags, some of
+which can be set and cleared by the
+.Ic enable
+and
+.Ic disable
+configuration commands, respectively.
+These are
+the
+.Cm auth ,
+.Cm bclient ,
+.Cm monitor ,
+.Cm pll ,
+.Cm pps
+and
+.Cm stats
+flags.
+See the
+.Xr ntpd 8
+documentation for the meaning of these flags.
+There
+are two additional flags which are read only, the
+.Cm kernel_pll
+and
+.Cm kernel_pps .
+These flags indicate
+the synchronization status when the precision time kernel
+modifications are in use.
+The
+.Sq kernel_pll
+indicates that
+the local clock is being disciplined by the kernel, while the
+.Sq kernel_pps
+indicates the kernel discipline is provided by the PPS
+signal.
+.PP
+The
+.Sq stability
+is the residual frequency error remaining
+after the system frequency correction is applied and is intended for
+maintenance and debugging.
+In most architectures, this value will
+initially decrease from as high as 500 ppm to a nominal value in
+the range .01 to 0.1 ppm.
+If it remains high for some time after
+starting the daemon, something may be wrong with the local clock,
+or the value of the kernel variable
+.Va kern.clockrate.tick
+may be
+incorrect.
+.PP
+The
+.Sq broadcastdelay
+shows the default broadcast delay,
+as set by the
+.Ic broadcastdelay
+configuration command.
+.PP
+The
+.Sq authdelay
+shows the default authentication delay,
+as set by the
+.Ic authdelay
+configuration command.
+.TP
+.BR Ic sysstats
+Print statistics counters maintained in the protocol
+module.
+.TP
+.BR Ic memstats
+Print statistics counters related to memory allocation
+code.
+.TP
+.BR Ic iostats
+Print statistics counters maintained in the input-output
+module.
+.TP
+.BR Ic timerstats
+Print statistics counters maintained in the timer/event queue
+support code.
+.TP
+.BR Ic reslist
+Obtain and print the server's restriction list.
+This list is
+(usually) printed in sorted order and may help to understand how
+the restrictions are applied.
+.TP
+.BR Ic monlist Op Ar version
+Obtain and print traffic counts collected and maintained by the
+monitor facility.
+The version number should not normally need to be
+specified.
+.TP
+.BR Ic clkbug Ar clock_peer_address Oo Ar ... Oc
+Obtain debugging information for a reference clock driver.
+This
+information is provided only by some clock drivers and is mostly
+undecodable without a copy of the driver source in hand.
+.SS "Runtime Configuration Requests"
+All requests which cause state changes in the server are
+authenticated by the server using a configured NTP key (the
+facility can also be disabled by the server by not configuring a
+key).
+The key number and the corresponding key must also be made
+known to
+.B .
+This can be done using the
+.Ic keyid
+and
+.Ic passwd
+commands, the latter of which will prompt at the terminal for a
+password to use as the encryption key.
+You will also be prompted
+automatically for both the key number and password the first time a
+command which would result in an authenticated request to the
+server is given.
+Authentication not only provides verification that
+the requester has permission to make such changes, but also gives
+an extra degree of protection again transmission errors.
+.PP
+Authenticated requests always include a timestamp in the packet
+data, which is included in the computation of the authentication
+code.
+This timestamp is compared by the server to its receive time
+stamp.
+If they differ by more than a small amount the request is
+rejected.
+This is done for two reasons.
+First, it makes simple
+replay attacks on the server, by someone who might be able to
+overhear traffic on your LAN, much more difficult.
+Second, it makes
+it more difficult to request configuration changes to your server
+from topologically remote hosts.
+While the reconfiguration facility
+will work well with a server on the local host, and may work
+adequately between time-synchronized hosts on the same LAN, it will
+work very poorly for more distant hosts.
+As such, if reasonable
+passwords are chosen, care is taken in the distribution and
+protection of keys and appropriate source address restrictions are
+applied, the run time reconfiguration facility should provide an
+adequate level of security.
+.PP
+The following commands all make authenticated requests.
+.TP
+.BR Xo Ic addpeer Ar peer_address
+[ "\fIkeyid\fR" ]
+[ "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+.Xc
+Add a configured peer association at the given address and
+operating in symmetric active mode.
+Note that an existing
+association with the same peer may be deleted when this command is
+executed, or may simply be converted to conform to the new
+configuration, as appropriate.
+If the optional
+\fIkeyid\fR
+is a
+nonzero integer, all outgoing packets to the remote server will
+have an authentication field attached encrypted with this key.
+If
+the value is 0 (or not given) no authentication will be done.
+The
+\fIversion\fR
+can be 1, 2 or 3 and defaults to 3.
+The
+.Cm prefer
+keyword indicates a preferred peer (and thus will
+be used primarily for clock synchronisation if possible).
+The
+preferred peer also determines the validity of the PPS signal - if
+the preferred peer is suitable for synchronisation so is the PPS
+signal.
+.TP
+.BR Xo Ic addserver Ar peer_address
+[ "\fIkeyid\fR" ]
+[ "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+.Xc
+Identical to the addpeer command, except that the operating
+mode is client.
+.TP
+.BR Xo Ic broadcast Ar peer_address
+[ "\fIkeyid\fR" ]
+[ "\fIversion\fR" ]
+[ "\fIprefer\fR" ]
+.Xc
+Identical to the addpeer command, except that the operating
+mode is broadcast.
+In this case a valid key identifier and key are
+required.
+The
+\fIpeer_address\fR
+parameter can be the broadcast
+address of the local network or a multicast group address assigned
+to NTP.
+If a multicast address, a multicast-capable kernel is
+required.
+.TP
+.BR Ic unconfig Ar peer_address Oo Ar ... Oc
+This command causes the configured bit to be removed from the
+specified peer(s).
+In many cases this will cause the peer
+association to be deleted.
+When appropriate, however, the
+association may persist in an unconfigured mode if the remote peer
+is willing to continue on in this fashion.
+.TP
+.BR Xo Ic fudge Ar peer_address
+[ "\fItime1\fR" ]
+[ "\fItime2\fR" ]
+[ "\fIstratum\fR" ]
+[ "\fIrefid\fR" ]
+.Xc
+This command provides a way to set certain data for a reference
+clock.
+See the source listing for further information.
+.TP
+.BR Xo Ic enable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+.TP
+.BR Xo Ic disable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+These commands operate in the same way as the
+.Ic enable
+and
+.Ic disable
+configuration file commands of
+.Xr ntpd 8 .
+.in +4
+.ti -4
+.IR Cm auth
+Enables the server to synchronize with unconfigured peers only
+if the peer has been correctly authenticated using either public key
+or private key cryptography.
+The default for this flag is enable.
+.ti -4
+.IR Cm bclient
+Enables the server to listen for a message from a broadcast or
+multicast server, as in the multicastclient command with
+default address.
+The default for this flag is disable.
+.ti -4
+.IR Cm calibrate
+Enables the calibrate feature for reference clocks.
+The default for this flag is disable.
+.ti -4
+.IR Cm kernel
+Enables the kernel time discipline, if available.
+The default for this flag is enable if support is available, otherwise disable.
+.ti -4
+.IR Cm monitor
+Enables the monitoring facility.
+See the
+.Xr ntpdc 8 .
+program and the monlist command or further information.
+The default for this flag is enable.
+.ti -4
+.IR Cm ntp
+Enables time and frequency discipline.
+In effect, this switch opens and closes the feedback loop,
+which is useful for testing.
+The default for this flag is enable.
+.ti -4
+.IR Cm pps
+Enables the pulse-per-second (PPS) signal when frequency
+and time is disciplined by the precision time kernel modifications.
+See the
+.Qq A Kernel Model for Precision Timekeeping
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page for further information.
+The default for this flag is disable.
+.ti -4
+.IR Cm stats
+Enables the statistics facility.
+See the
+.Sx Monitoring Options
+section of
+.Xr ntp.conf 5
+for further information.
+The default for this flag is disable.
+.in -4
+.TP
+.BR Xo Ic restrict Ar address Ar mask
+\fIflag Oo Ar ... Oc\fR
+.Xc
+This command operates in the same way as the
+.Ic restrict
+configuration file commands of
+.Xr ntpd 8 .
+.TP
+.BR Xo Ic unrestrict Ar address Ar mask
+\fIflag Oo Ar ... Oc\fR
+.Xc
+Unrestrict the matching entry from the restrict list.
+.TP
+.BR Xo Ic delrestrict Ar address Ar mask
+[ "\fIntpport\fR" ]
+.Xc
+Delete the matching entry from the restrict list.
+.TP
+.BR Ic readkeys
+Causes the current set of authentication keys to be purged and
+a new set to be obtained by rereading the keys file (which must
+have been specified in the
+.Xr ntpd 8
+configuration file).
+This
+allows encryption keys to be changed without restarting the
+server.
+.TP
+.BR Ic trustedkey Ar keyid Oo Ar ... Oc
+.TP
+.BR Ic untrustedkey Ar keyid Oo Ar ... Oc
+These commands operate in the same way as the
+.Ic trustedkey
+and
+.Ic untrustedkey
+configuration file
+commands of
+.Xr ntpd 8 .
+.TP
+.BR Ic authinfo
+Returns information concerning the authentication module,
+including known keys and counts of encryptions and decryptions
+which have been done.
+.TP
+.BR Ic traps
+Display the traps set in the server.
+See the source listing for
+further information.
+.TP
+.BR Xo Ic addtrap Ar address
+[ "\fIport\fR" ]
+[ "\fIinterface\fR" ]
+.Xc
+Set a trap for asynchronous messages.
+See the source listing
+for further information.
+.TP
+.BR Xo Ic clrtrap Ar address
+[ "\fIport\fR" ]
+[ "\fIinterface\fR" ]
+.Xc
+Clear a trap for asynchronous messages.
+See the source listing
+for further information.
+.TP
+.BR Ic reset
+Clear the statistics counters in various modules of the server.
+See the source listing for further information.
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH "FILES"
libopts had an internal operational error. Please report
it to autogen-users@lists.sourceforge.net. Thank you.
.SH "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpd 8
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 3)
+.%O RFC1305
+.Re
.SH AUTHORS
+The formatting directives in this document came from FreeBSD.
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The
+.B
+utility is a crude hack.
+Much of the information it shows is
+deadly boring and could only be loved by its implementer.
+The
+program was designed so that new (and temporary) features were easy
+to hack in, at great expense to the program's ease of use.
+Despite
+this, the program is occasionally useful.
+.PP
+Please report bugs to http://bugs.ntp.org .Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH "NOTES"
This manual page was \fIAutoGen\fP-erated from the \fBntpdc\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTPDC @NTPDC_MS@ User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntpdc-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:18 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:09:58 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpdc-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
[ host ...]
.Pp
.Sh DESCRIPTION
+.Nm
+is a utility program used to query
+.Xr ntpd 8
+about its
+current state and to request changes in that state.
+It uses NTP mode 7 control message formats described in the source code.
+The program may
+be run either in interactive mode or controlled using command line
+arguments.
+Extensive state and statistics information is available
+through the
+.Nm
+interface.
+In addition, nearly all the
+configuration options which can be specified at startup using
+ntpd's configuration file may also be specified at run time using
+.Nm .
.Sh "OPTIONS"
.Bl -tag
.It \-4 ", " -\-ipv4
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.Sh USAGE
+If one or more request options are included on the command line
+when
+.Nm
+is executed, each of the requests will be sent
+to the NTP servers running on each of the hosts given as command
+line arguments, or on localhost by default.
+If no request options
+are given,
+.Nm
+will attempt to read commands from the
+standard input and execute these on the NTP server running on the
+first host given on the command line, again defaulting to localhost
+when no other host is specified.
+The
+.Nm
+utility will prompt for
+commands if the standard input is a terminal device.
+.Pp
+The
+.Nm
+utility uses NTP mode 7 packets to communicate with the
+NTP server, and hence can be used to query any compatible server on
+the network which permits it.
+Note that since NTP is a UDP protocol
+this communication will be somewhat unreliable, especially over
+large distances in terms of network topology.
+The
+.Nm
+utility makes
+no attempt to retransmit requests, and will time requests out if
+the remote host is not heard from within a suitable timeout
+time.
+.Pp
+The operation of
+.Nm
+are specific to the particular
+implementation of the
+.Xr ntpd 8
+daemon and can be expected to
+work only with this and maybe some previous versions of the daemon.
+Requests from a remote
+.Nm
+utility which affect the
+state of the local server must be authenticated, which requires
+both the remote program and local server share a common key and key
+identifier.
+.Pp
+Note that in contexts where a host name is expected, a
+.Fl 4
+qualifier preceding the host name forces DNS resolution to the IPv4 namespace,
+while a
+.Fl 6
+qualifier forces DNS resolution to the IPv6 namespace.
+Specifying a command line option other than
+.Fl i
+or
+.Fl n
+will cause the specified query (queries) to be sent to
+the indicated host(s) immediately.
+Otherwise,
+.Nm
+will
+attempt to read interactive format commands from the standard
+input.
+.Ss "Interactive Commands"
+Interactive format commands consist of a keyword followed by zero
+to four arguments.
+Only enough characters of the full keyword to
+uniquely identify the command need be typed.
+The output of a
+command is normally sent to the standard output, but optionally the
+output of individual commands may be sent to a file by appending a
+.Ql \&> ,
+followed by a file name, to the command line.
+.Pp
+A number of interactive format commands are executed entirely
+within the
+.Nm
+utility itself and do not result in NTP
+mode 7 requests being sent to a server.
+These are described
+following.
+.Bl -tag -width indent
+.It Ic \&? Ar command_keyword
+.It Ic help Ar command_keyword
+A
+.Sq Ic \&?
+will print a list of all the command
+keywords known to this incarnation of
+.Nm .
+A
+.Sq Ic \&?
+followed by a command keyword will print function and usage
+information about the command.
+This command is probably a better
+source of information about
+.Xr ntpq 8
+than this manual
+page.
+.It Ic delay Ar milliseconds
+Specify a time interval to be added to timestamps included in
+requests which require authentication.
+This is used to enable
+(unreliable) server reconfiguration over long delay network paths
+or between machines whose clocks are unsynchronized.
+Actually the
+server does not now require timestamps in authenticated requests,
+so this command may be obsolete.
+.It Ic host Ar hostname
+Set the host to which future queries will be sent.
+Hostname may
+be either a host name or a numeric address.
+.It Ic hostnames Op Cm yes | Cm no
+If
+.Cm yes
+is specified, host names are printed in
+information displays.
+If
+.Cm no
+is specified, numeric
+addresses are printed instead.
+The default is
+.Cm yes ,
+unless
+modified using the command line
+.Fl n
+switch.
+.It Ic keyid Ar keyid
+This command allows the specification of a key number to be
+used to authenticate configuration requests.
+This must correspond
+to a key number the server has been configured to use for this
+purpose.
+.It Ic quit
+Exit
+.Nm .
+.It Ic passwd
+This command prompts you to type in a password (which will not
+be echoed) which will be used to authenticate configuration
+requests.
+The password must correspond to the key configured for
+use by the NTP server for this purpose if such requests are to be
+successful.
+.It Ic timeout Ar milliseconds
+Specify a timeout period for responses to server queries.
+The
+default is about 8000 milliseconds.
+Note that since
+.Nm
+retries each query once after a timeout, the total waiting time for
+a timeout will be twice the timeout value set.
+.El
+.Ss "Control Message Commands"
+Query commands result in NTP mode 7 packets containing requests for
+information being sent to the server.
+These are read-only commands
+in that they make no modification of the server configuration
+state.
+.Bl -tag -width indent
+.It Ic listpeers
+Obtains and prints a brief list of the peers for which the
+server is maintaining state.
+These should include all configured
+peer associations as well as those peers whose stratum is such that
+they are considered by the server to be possible future
+synchronization candidates.
+.It Ic peers
+Obtains a list of peers for which the server is maintaining
+state, along with a summary of that state.
+Summary information
+includes the address of the remote peer, the local interface
+address (0.0.0.0 if a local address has yet to be determined), the
+stratum of the remote peer (a stratum of 16 indicates the remote
+peer is unsynchronized), the polling interval, in seconds, the
+reachability register, in octal, and the current estimated delay,
+offset and dispersion of the peer, all in seconds.
+.Pp
+The character in the left margin indicates the mode this peer
+entry is operating in.
+A
+.Ql \&+
+denotes symmetric active, a
+.Ql \&-
+indicates symmetric passive, a
+.Ql \&=
+means the
+remote server is being polled in client mode, a
+.Ql \&^
+indicates that the server is broadcasting to this address, a
+.Ql \&~
+denotes that the remote peer is sending broadcasts and a
+.Ql \&~
+denotes that the remote peer is sending broadcasts and a
+.Ql \&*
+marks the peer the server is currently synchronizing
+to.
+.Pp
+The contents of the host field may be one of four forms.
+It may
+be a host name, an IP address, a reference clock implementation
+name with its parameter or
+.Fn REFCLK "implementation_number" "parameter" .
+On
+.Ic hostnames
+.Cm no
+only IP-addresses
+will be displayed.
+.It Ic dmpeers
+A slightly different peer summary list.
+Identical to the output
+of the
+.Ic peers
+command, except for the character in the
+leftmost column.
+Characters only appear beside peers which were
+included in the final stage of the clock selection algorithm.
+A
+.Ql \&.
+indicates that this peer was cast off in the falseticker
+detection, while a
+.Ql \&+
+indicates that the peer made it
+through.
+A
+.Ql \&*
+denotes the peer the server is currently
+synchronizing with.
+.It Ic showpeer Ar peer_address Oo Ar ... Oc
+Shows a detailed display of the current peer variables for one
+or more peers.
+Most of these values are described in the NTP
+Version 2 specification.
+.It Ic pstats Ar peer_address Oo Ar ... Oc
+Show per-peer statistic counters associated with the specified
+peer(s).
+.It Ic clockinfo Ar clock_peer_address Oo Ar ... Oc
+Obtain and print information concerning a peer clock.
+The
+values obtained provide information on the setting of fudge factors
+and other clock performance information.
+.It Ic kerninfo
+Obtain and print kernel phase-lock loop operating parameters.
+This information is available only if the kernel has been specially
+modified for a precision timekeeping function.
+.It Ic loopinfo Op Cm oneline | Cm multiline
+Print the values of selected loop filter variables.
+The loop
+filter is the part of NTP which deals with adjusting the local
+system clock.
+The
+.Sq offset
+is the last offset given to the
+loop filter by the packet processing code.
+The
+.Sq frequency
+is the frequency error of the local clock in parts-per-million
+(ppm).
+The
+.Sq time_const
+controls the stiffness of the
+phase-lock loop and thus the speed at which it can adapt to
+oscillator drift.
+The
+.Sq watchdog timer
+value is the number
+of seconds which have elapsed since the last sample offset was
+given to the loop filter.
+The
+.Cm oneline
+and
+.Cm multiline
+options specify the format in which this
+information is to be printed, with
+.Cm multiline
+as the
+default.
+.It Ic sysinfo
+Print a variety of system state variables, i.e., state related
+to the local server.
+All except the last four lines are described
+in the NTP Version 3 specification, RFC-1305.
+.Pp
+The
+.Sq system flags
+show various system flags, some of
+which can be set and cleared by the
+.Ic enable
+and
+.Ic disable
+configuration commands, respectively.
+These are
+the
+.Cm auth ,
+.Cm bclient ,
+.Cm monitor ,
+.Cm pll ,
+.Cm pps
+and
+.Cm stats
+flags.
+See the
+.Xr ntpd 8
+documentation for the meaning of these flags.
+There
+are two additional flags which are read only, the
+.Cm kernel_pll
+and
+.Cm kernel_pps .
+These flags indicate
+the synchronization status when the precision time kernel
+modifications are in use.
+The
+.Sq kernel_pll
+indicates that
+the local clock is being disciplined by the kernel, while the
+.Sq kernel_pps
+indicates the kernel discipline is provided by the PPS
+signal.
+.Pp
+The
+.Sq stability
+is the residual frequency error remaining
+after the system frequency correction is applied and is intended for
+maintenance and debugging.
+In most architectures, this value will
+initially decrease from as high as 500 ppm to a nominal value in
+the range .01 to 0.1 ppm.
+If it remains high for some time after
+starting the daemon, something may be wrong with the local clock,
+or the value of the kernel variable
+.Va kern.clockrate.tick
+may be
+incorrect.
+.Pp
+The
+.Sq broadcastdelay
+shows the default broadcast delay,
+as set by the
+.Ic broadcastdelay
+configuration command.
+.Pp
+The
+.Sq authdelay
+shows the default authentication delay,
+as set by the
+.Ic authdelay
+configuration command.
+.It Ic sysstats
+Print statistics counters maintained in the protocol
+module.
+.It Ic memstats
+Print statistics counters related to memory allocation
+code.
+.It Ic iostats
+Print statistics counters maintained in the input-output
+module.
+.It Ic timerstats
+Print statistics counters maintained in the timer/event queue
+support code.
+.It Ic reslist
+Obtain and print the server's restriction list.
+This list is
+(usually) printed in sorted order and may help to understand how
+the restrictions are applied.
+.It Ic monlist Op Ar version
+Obtain and print traffic counts collected and maintained by the
+monitor facility.
+The version number should not normally need to be
+specified.
+.It Ic clkbug Ar clock_peer_address Oo Ar ... Oc
+Obtain debugging information for a reference clock driver.
+This
+information is provided only by some clock drivers and is mostly
+undecodable without a copy of the driver source in hand.
+.El
+.Ss "Runtime Configuration Requests"
+All requests which cause state changes in the server are
+authenticated by the server using a configured NTP key (the
+facility can also be disabled by the server by not configuring a
+key).
+The key number and the corresponding key must also be made
+known to
+.Nm .
+This can be done using the
+.Ic keyid
+and
+.Ic passwd
+commands, the latter of which will prompt at the terminal for a
+password to use as the encryption key.
+You will also be prompted
+automatically for both the key number and password the first time a
+command which would result in an authenticated request to the
+server is given.
+Authentication not only provides verification that
+the requester has permission to make such changes, but also gives
+an extra degree of protection again transmission errors.
+.Pp
+Authenticated requests always include a timestamp in the packet
+data, which is included in the computation of the authentication
+code.
+This timestamp is compared by the server to its receive time
+stamp.
+If they differ by more than a small amount the request is
+rejected.
+This is done for two reasons.
+First, it makes simple
+replay attacks on the server, by someone who might be able to
+overhear traffic on your LAN, much more difficult.
+Second, it makes
+it more difficult to request configuration changes to your server
+from topologically remote hosts.
+While the reconfiguration facility
+will work well with a server on the local host, and may work
+adequately between time-synchronized hosts on the same LAN, it will
+work very poorly for more distant hosts.
+As such, if reasonable
+passwords are chosen, care is taken in the distribution and
+protection of keys and appropriate source address restrictions are
+applied, the run time reconfiguration facility should provide an
+adequate level of security.
+.Pp
+The following commands all make authenticated requests.
+.Bl -tag -width indent
+.It Xo Ic addpeer Ar peer_address
+.Op Ar keyid
+.Op Ar version
+.Op Cm prefer
+.Xc
+Add a configured peer association at the given address and
+operating in symmetric active mode.
+Note that an existing
+association with the same peer may be deleted when this command is
+executed, or may simply be converted to conform to the new
+configuration, as appropriate.
+If the optional
+.Ar keyid
+is a
+nonzero integer, all outgoing packets to the remote server will
+have an authentication field attached encrypted with this key.
+If
+the value is 0 (or not given) no authentication will be done.
+The
+.Ar version
+can be 1, 2 or 3 and defaults to 3.
+The
+.Cm prefer
+keyword indicates a preferred peer (and thus will
+be used primarily for clock synchronisation if possible).
+The
+preferred peer also determines the validity of the PPS signal - if
+the preferred peer is suitable for synchronisation so is the PPS
+signal.
+.It Xo Ic addserver Ar peer_address
+.Op Ar keyid
+.Op Ar version
+.Op Cm prefer
+.Xc
+Identical to the addpeer command, except that the operating
+mode is client.
+.It Xo Ic broadcast Ar peer_address
+.Op Ar keyid
+.Op Ar version
+.Op Cm prefer
+.Xc
+Identical to the addpeer command, except that the operating
+mode is broadcast.
+In this case a valid key identifier and key are
+required.
+The
+.Ar peer_address
+parameter can be the broadcast
+address of the local network or a multicast group address assigned
+to NTP.
+If a multicast address, a multicast-capable kernel is
+required.
+.It Ic unconfig Ar peer_address Oo Ar ... Oc
+This command causes the configured bit to be removed from the
+specified peer(s).
+In many cases this will cause the peer
+association to be deleted.
+When appropriate, however, the
+association may persist in an unconfigured mode if the remote peer
+is willing to continue on in this fashion.
+.It Xo Ic fudge Ar peer_address
+.Op Cm time1
+.Op Cm time2
+.Op Ar stratum
+.Op Ar refid
+.Xc
+This command provides a way to set certain data for a reference
+clock.
+See the source listing for further information.
+.It Xo Ic enable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+.It Xo Ic disable
+.Oo
+.Cm auth | Cm bclient |
+.Cm calibrate | Cm kernel |
+.Cm monitor | Cm ntp |
+.Cm pps | Cm stats
+.Oc
+.Xc
+These commands operate in the same way as the
+.Ic enable
+and
+.Ic disable
+configuration file commands of
+.Xr ntpd 8 .
+.Bl -tag -width indent
+.It Cm auth
+Enables the server to synchronize with unconfigured peers only
+if the peer has been correctly authenticated using either public key
+or private key cryptography.
+The default for this flag is enable.
+.It Cm bclient
+Enables the server to listen for a message from a broadcast or
+multicast server, as in the multicastclient command with
+default address.
+The default for this flag is disable.
+.It Cm calibrate
+Enables the calibrate feature for reference clocks.
+The default for this flag is disable.
+.It Cm kernel
+Enables the kernel time discipline, if available.
+The default for this flag is enable if support is available, otherwise disable.
+.It Cm monitor
+Enables the monitoring facility.
+See the
+.Xr ntpdc 8 .
+program and the monlist command or further information.
+The default for this flag is enable.
+.It Cm ntp
+Enables time and frequency discipline.
+In effect, this switch opens and closes the feedback loop,
+which is useful for testing.
+The default for this flag is enable.
+.It Cm pps
+Enables the pulse-per-second (PPS) signal when frequency
+and time is disciplined by the precision time kernel modifications.
+See the
+.Qq A Kernel Model for Precision Timekeeping
+(available as part of the HTML documentation
+provided in
+.Pa /usr/share/doc/ntp )
+page for further information.
+The default for this flag is disable.
+.It Cm stats
+Enables the statistics facility.
+See the
+.Sx Monitoring Options
+section of
+.Xr ntp.conf 5
+for further information.
+The default for this flag is disable.
+.El
+.It Xo Ic restrict Ar address Ar mask
+.Ar flag Oo Ar ... Oc
+.Xc
+This command operates in the same way as the
+.Ic restrict
+configuration file commands of
+.Xr ntpd 8 .
+.It Xo Ic unrestrict Ar address Ar mask
+.Ar flag Oo Ar ... Oc
+.Xc
+Unrestrict the matching entry from the restrict list.
+.It Xo Ic delrestrict Ar address Ar mask
+.Op Cm ntpport
+.Xc
+Delete the matching entry from the restrict list.
+.It Ic readkeys
+Causes the current set of authentication keys to be purged and
+a new set to be obtained by rereading the keys file (which must
+have been specified in the
+.Xr ntpd 8
+configuration file).
+This
+allows encryption keys to be changed without restarting the
+server.
+.It Ic trustedkey Ar keyid Oo Ar ... Oc
+.It Ic untrustedkey Ar keyid Oo Ar ... Oc
+These commands operate in the same way as the
+.Ic trustedkey
+and
+.Ic untrustedkey
+configuration file
+commands of
+.Xr ntpd 8 .
+.It Ic authinfo
+Returns information concerning the authentication module,
+including known keys and counts of encryptions and decryptions
+which have been done.
+.It Ic traps
+Display the traps set in the server.
+See the source listing for
+further information.
+.It Xo Ic addtrap Ar address
+.Op Ar port
+.Op Ar interface
+.Xc
+Set a trap for asynchronous messages.
+See the source listing
+for further information.
+.It Xo Ic clrtrap Ar address
+.Op Ar port
+.Op Ar interface
+.Xc
+Clear a trap for asynchronous messages.
+See the source listing
+for further information.
+.It Ic reset
+Clear the statistics counters in various modules of the server.
+See the source listing for further information.
+.El
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh "FILES"
it to autogen-users@lists.sourceforge.net. Thank you.
.El
.Sh "SEE ALSO"
+.Xr ntp.conf 5 ,
+.Xr ntpd 8
+.Rs
+.%A David L. Mills
+.%T Network Time Protocol (Version 3)
+.%O RFC1305
+.Re
.Sh AUTHORS
+The formatting directives in this document came from FreeBSD.
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+The
+.Nm
+utility is a crude hack.
+Much of the information it shows is
+deadly boring and could only be loved by its implementer.
+The
+program was designed so that new (and temporary) features were easy
+to hack in, at great expense to the program's ease of use.
+Despite
+this, the program is occasionally useful.
+.Pp
+Please report bugs to http://bugs.ntp.org .Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh "NOTES"
This manual page was \fIAutoGen\fP-erated from the \fBntpdc\fP
option definitions.
#
# EDIT THIS FILE WITH CAUTION (invoke-ntpq.texi)
#
-# It has been AutoGen-ed January 2, 2013 at 02:20:33 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:10:28 PM by AutoGen 5.17.1pre11
# From the definitions ntpq-opts.def
# and the template file agtexi-cmd.tpl
@end ignore
Specifying a
command line option other than
-@code{-i} or
-@code{-n} will
+@code{-i}
+or
+@code{-n}
+will
cause the specified query (queries) to be sent to the indicated
host(s) immediately.
Otherwise,
@node Internal Commands
@section Internal Commands
-Internal Commands
+
Interactive format commands consist of a keyword followed by zero
to four arguments.
Only enough characters of the full keyword to
utility itself and do not result in NTP mode 6
requests being sent to a server.
These are described following.
-@table @samp
-@item Ic
-@item Ic
+@table @asis
+
+@item ? [@kbd{command_keyword}]
+@item @code{help} [@kbd{command_keyword}]
A
-@quoteleft{}\&?@quoteright{}
+@quoteleft{}?@quoteright{}
by itself will print a list of all the command
keywords known to this incarnation of
@code{ntpq}.
A
-@quoteleft{}\&?@quoteright{}
+@quoteleft{}?@quoteright{}
followed by a command keyword will print function and usage
information about the command.
This command is probably a better
@code{ntpq}
than this manual
page.
-@item Ic
-@code{...} @item Ic
-@item Ic
+@item @code{addvars} @kbd{variable_name}[@code{=value}]
+@code{...}
+
+@item@code{rmvars}@kbd{variable_name}@code{...}
+@item@code{clearvars}
The data carried by NTP mode 6 messages consists of a list of
items of the form
-@quoteleft{}variable_name=value@quoteright{},
+@quoteleft{}variable_name=value,@quoteright{}
where the
@quoteleft{}=value@quoteright{}
is ignored, and can be omitted,
@code{ntpq}
utility maintains an internal list in which data to be included in control
messages can be assembled, and sent using the
-@code{readlist} and
-@code{writelist} commands described below.
+@code{readlist}
+and
+@code{writelist}
+commands described below.
The
-@code{addvars} command allows variables and their optional values to be added to
+@code{addvars}
+command allows variables and their optional values to be added to
the list.
If more than one variable is to be added, the list should
be comma-separated and not contain white space.
The
-@code{rmvars} command can be used to remove individual variables from the list,
+@code{rmvars}
+command can be used to remove individual variables from the list,
while the
-@code{clearlist} command removes all variables from the
+@code{clearlist}
+command removes all variables from the
list.
-@item Ic
+@item@code{authenticate}[yes]|no
Normally
@code{ntpq}
does not authenticate requests unless
they are write requests.
The command
-@quoteleft{}authenticate yes@quoteright{}
+@quoteleft{}authenticateyes@quoteright{}
causes
@code{ntpq}
to send authentication with all requests it
Authenticated requests causes some servers to handle
requests slightly differently, and can occasionally melt the CPU in
fuzzballs if you turn authentication on before doing a
-@code{peer} display.
+@code{peer}
+display.
The command
@quoteleft{}authenticate@quoteright{}
causes
to display whether or not
@code{ntpq}
is currently autheinticating requests.
-@item Ic
+@item@code{cooked}
Causes output from query commands to be "cooked", so that
variables which are recognized by
@code{ntpq}
@code{ntpq}
thinks should have a decodable value but didn't are
marked with a trailing
-@quoteleft{}\&?@quoteright{}.
-@item Xo
-@code{debug} .Oo
-@code{more} | @code{less} | @code{off} .Oc
+@quoteleft{}?.@quoteright{}
+@item@code{debug}Oo@code{more}|@code{less}|@code{off}Oc
With no argument, displays the current debug level.
Otherwise, the debug level is changed to the indicated level.
-@item Ic
+@item@code{delay}@kbd{milliseconds}
Specify a time interval to be added to timestamps included in
requests which require authentication.
This is used to enable
Actually the
server does not now require timestamps in authenticated requests,
so this command may be obsolete.
-@item Ic
+@item@code{host}@kbd{hostname}
Set the host to which future queries will be sent.
-@code{hostname} may be either a host name or a numeric address.
-@item Ic
+@kbd{hostname}
+may be either a host name or a numeric address.
+@item@code{hostnames}[@code{yes}|@code{Cm}@code{no}]
If
-@code{yes} is specified, host names are printed in
+@code{yes}
+is specified, host names are printed in
information displays.
If
-@code{no} is specified, numeric
+@code{no}
+is specified, numeric
addresses are printed instead.
The default is
-@code{yes}, unless
+@code{yes},
+unless
modified using the command line
-@code{-n} switch.
-@item Ic
+@code{-n}
+switch.
+@item@code{keyid}@kbd{keyid}
This command allows the specification of a key number to be
used to authenticate configuration requests.
This must correspond
to a key number the server has been configured to use for this
purpose.
-@item Ic
-@code{1} | @code{2} | @code{3} | @code{4} .Oc
+@item@code{ntpversion}@code{Oo}
+@code{1}|
+@code{2}|
+@code{3}|
+@code{4}
+Oc
+
Sets the NTP version number which
@code{ntpq}
claims in
to be no servers left which demand version 1.
With no argument, displays the current NTP version that will be used
when communicating with servers.
-@item Ic
+@item@code{quit}
Exit
@code{ntpq}
-@item Ic
+@item@code{passwd}
This command prompts you to type in a password (which will not
be echoed) which will be used to authenticate configuration
requests.
The password must correspond to the key configured for
use by the NTP server for this purpose if such requests are to be
successful.
-@item Ic
+@item@code{raw}
Causes all output from query commands is printed as received
from the remote server.
The only formating/interpretation done on
the data is to transform nonascii data into a printable (but barely
understandable) form.
-@item Ic
+@item@code{timeout}@kbd{milliseconds}
Specify a timeout period for responses to server queries.
The
default is about 5000 milliseconds.
@exampleindent 0
@example
-ntpq - standard NTP query program - Ver. 4.2.7p343
+ntpq - standard NTP query program - Ver. 4.2.7p344
USAGE: ntpq [ -<flag> [<val>] | --<name>[@{=| @}<val>] ]... [ host ...]
Flg Arg Option-Name Description
-4 no ipv4 Force IPv4 DNS name resolution
/*
* EDIT THIS FILE WITH CAUTION (ntpq-opts.c)
*
- * It has been AutoGen-ed January 2, 2013 at 02:20:21 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:10:02 PM by AutoGen 5.17.1pre11
* From the definitions ntpq-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This source file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* ntpq option static const strings
*/
static char const ntpq_opt_strs[1833] =
-/* 0 */ "ntpq 4.2.7p343\n"
+/* 0 */ "ntpq 4.2.7p344\n"
"Copyright (C) 1970-2013 The University of Delaware, all rights reserved.\n"
"This is free software. It is licensed for use, modification and\n"
"redistribution under the terms of the NTP License, copies of which\n"
/* 1627 */ "no-load-opts\0"
/* 1640 */ "no\0"
/* 1643 */ "NTPQ\0"
-/* 1648 */ "ntpq - standard NTP query program - Ver. 4.2.7p343\n"
+/* 1648 */ "ntpq - standard NTP query program - Ver. 4.2.7p344\n"
"USAGE: %s [ -<flag> [<val>] | --<name>[{=| }<val>] ]... [ host ...]\n\0"
/* 1769 */ "$HOME\0"
/* 1775 */ ".\0"
/* 1777 */ ".ntprc\0"
/* 1784 */ "http://bugs.ntp.org, bugs@ntp.org\0"
-/* 1818 */ "ntpq 4.2.7p343";
+/* 1818 */ "ntpq 4.2.7p344";
/*
* ipv4 option description with
#define zExplain (NULL)
#define zDetail (NULL)
#define zFullVersion (ntpq_opt_strs+1818)
-/* extracted from optcode.tlib near line 350 */
+/* extracted from optcode.tlib near line 353 */
#if defined(ENABLE_NLS)
# define OPTPROC_BASE OPTPROC_TRANSLATE
static void
doOptDebug_Level(tOptions* pOptions, tOptDesc* pOptDesc)
{
+ /*
+ * Be sure the flag-code[0] handles special values for the options pointer
+ * viz. (poptions <= OPTPROC_EMIT_LIMIT) *and also* the special flag bit
+ * ((poptdesc->fOptState & OPTST_RESET) != 0) telling the option to
+ * reset its state.
+ */
/* extracted from debug-opt.def, line 15 */
OPT_VALUE_SET_DEBUG_LEVEL++;
(void)pOptDesc;
(void)pOptions;
}
#endif /* defined(TEST_NTPQ_OPTS) */
-/* extracted from optmain.tlib near line 48 */
+/* extracted from optmain.tlib near line 46 */
#if defined(TEST_NTPQ_OPTS) /* TEST MAIN PROCEDURE: */
return res;
}
#endif /* defined TEST_NTPQ_OPTS */
-/* extracted from optmain.tlib near line 1146 */
+/* extracted from optmain.tlib near line 1188 */
/**
* The directory containing the data associated with ntpq.
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#ifdef HAVE_DCGETTEXT
+# include <gettext.h>
+#endif
#include <autoopts/usage-txt.h>
-static char* AO_gettext(char const* pz);
-static void coerce_it(void** s);
+static char * AO_gettext(char const * pz);
+static void coerce_it(void ** s);
/**
- * AutoGen specific wrapper function for gettext.
- * It relies on the macro _() to convert from English to the target
- * language, then strdup-duplicates the result string.
+ * AutoGen specific wrapper function for gettext. It relies on the macro _()
+ * to convert from English to the target language, then strdup-duplicates the
+ * result string. It tries the "libopts" domain first, then whatever has been
+ * set via the \a textdomain(3) call.
*
* @param[in] pz the input text used as a lookup key.
* @returns the translated text (if there is one),
* or the original text (if not).
*/
static char *
-AO_gettext(char const* pz)
+AO_gettext(char const * pz)
{
- char* pzRes;
+ char * res;
if (pz == NULL)
return NULL;
- pzRes = _(pz);
- if (pzRes == pz)
- return pzRes;
- pzRes = strdup(pzRes);
- if (pzRes == NULL) {
+#ifdef HAVE_DCGETTEXT
+ /*
+ * While processing the option_xlateable_txt data, try to use the
+ * "libopts" domain. Once we switch to the option descriptor data,
+ * do *not* use that domain.
+ */
+ if (option_xlateable_txt.field_ct != 0) {
+ res = dgettext("libopts", pz);
+ if (res == pz)
+ res = (char *)(void *)_(pz);
+ } else
+ res = (char *)(void *)_(pz);
+#else
+ res = (char *)(void *)_(pz);
+#endif
+ if (res == pz)
+ return res;
+ res = strdup(res);
+ if (res == NULL) {
fputs(_("No memory for duping translated strings\n"), stderr);
exit(NTPQ_EXIT_FAILURE);
}
- return pzRes;
+ return res;
}
-static void coerce_it(void** s) { *s = AO_gettext(*s);
+/**
+ * All the pointers we use are marked "* const", but they are stored in
+ * writable memory. Coerce the mutability and set the pointer.
+ */
+static void coerce_it(void ** s) { *s = AO_gettext(*s);
}
/**
static void
translate_option_strings(void)
{
- tOptions * const pOpt = &ntpqOptions;
+ tOptions * const opts = &ntpqOptions;
/*
* Guard against re-translation. It won't work. The strings will have
* been changed by the first pass through this code. One shot only.
*/
- if (option_usage_text.field_ct != 0) {
+ if (option_xlateable_txt.field_ct != 0) {
/*
* Do the translations. The first pointer follows the field count
* field. The field count field is the size of a pointer.
*/
- tOptDesc * pOD = pOpt->pOptDesc;
- char ** ppz = (char**)(void*)&(option_usage_text);
- int ix = option_usage_text.field_ct;
+ tOptDesc * od = opts->pOptDesc;
+ char ** ppz = (char**)(void*)&(option_xlateable_txt);
+ int ix = option_xlateable_txt.field_ct;
do {
- ppz++;
+ ppz++; /* skip over field_ct */
*ppz = AO_gettext(*ppz);
} while (--ix > 0);
-
- coerce_it((void*)&(pOpt->pzCopyright));
- coerce_it((void*)&(pOpt->pzCopyNotice));
- coerce_it((void*)&(pOpt->pzFullVersion));
- coerce_it((void*)&(pOpt->pzUsageTitle));
- coerce_it((void*)&(pOpt->pzExplain));
- coerce_it((void*)&(pOpt->pzDetail));
- coerce_it((void*)&(pOpt->pzPackager));
- option_usage_text.field_ct = 0;
-
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++)
- coerce_it((void*)&(pOD->pzText));
+ /* prevent re-translation and disable "libopts" domain lookup */
+ option_xlateable_txt.field_ct = 0;
+
+ coerce_it((void*)&(opts->pzCopyright));
+ coerce_it((void*)&(opts->pzCopyNotice));
+ coerce_it((void*)&(opts->pzFullVersion));
+ coerce_it((void*)&(opts->pzUsageTitle));
+ coerce_it((void*)&(opts->pzExplain));
+ coerce_it((void*)&(opts->pzDetail));
+ coerce_it((void*)&(opts->pzPackager));
+
+ for (ix = opts->optCt; ix > 0; ix--, od++)
+ coerce_it((void*)&(od->pzText));
}
- if ((pOpt->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
- tOptDesc * pOD = pOpt->pOptDesc;
+ if ((opts->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
+ tOptDesc * od = opts->pOptDesc;
int ix;
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++) {
- coerce_it((void*)&(pOD->pz_Name));
- coerce_it((void*)&(pOD->pz_DisableName));
- coerce_it((void*)&(pOD->pz_DisablePfx));
+ for (ix = opts->optCt; ix > 0; ix--, od++) {
+ coerce_it((void*)&(od->pz_Name));
+ coerce_it((void*)&(od->pz_DisableName));
+ coerce_it((void*)&(od->pz_DisablePfx));
}
- /* prevent re-translation */
ntpqOptions.fOptSet |= OPTPROC_NXLAT_OPT_CFG | OPTPROC_NXLAT_OPT;
}
}
/*
* EDIT THIS FILE WITH CAUTION (ntpq-opts.h)
*
- * It has been AutoGen-ed January 2, 2013 at 02:20:21 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:10:02 PM by AutoGen 5.17.1pre11
* From the definitions ntpq-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This header file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* tolerable version is at least as old as what was current when the header
* template was released.
*/
-#define AO_TEMPLATE_VERSION 147461
+#define AO_TEMPLATE_VERSION 151552
#if (AO_TEMPLATE_VERSION < OPTIONS_MINIMUM_VERSION) \
|| (AO_TEMPLATE_VERSION > OPTIONS_STRUCT_VERSION)
# error option template version mismatches autoopts/options.h header
} teOptIndex;
#define OPTION_CT 14
-#define NTPQ_VERSION "4.2.7p343"
-#define NTPQ_FULL_VERSION "ntpq 4.2.7p343"
+#define NTPQ_VERSION "4.2.7p344"
+#define NTPQ_FULL_VERSION "ntpq 4.2.7p344"
/*
* Interface defines for all options. Replace "n" with the UPPER_CASED
* Enumeration of ntpq exit codes
*/
typedef enum {
- NTPQ_EXIT_SUCCESS = 0,
- NTPQ_EXIT_FAILURE = 1,
- NTPQ_EXIT_NO_CONFIG_INPUT = 66,
- NTPQ_EXIT_LIBOPTS_FAILURE = 70
+ NTPQ_EXIT_SUCCESS = 0,
+ NTPQ_EXIT_FAILURE = 1,
+ NTPQ_EXIT_USAGE_ERROR = 64,
+ NTPQ_EXIT_NO_CONFIG_INPUT = 66,
+ NTPQ_EXIT_LIBOPTS_FAILURE = 70
} ntpq_exit_code_t;
/*
* Make sure there are no #define name conflicts with the option names
#define SET_OPT_SAVE_OPTS(a) STMTS( \
DESC(SAVE_OPTS).fOptState &= OPTST_PERSISTENT_MASK; \
DESC(SAVE_OPTS).fOptState |= OPTST_SET; \
- DESC(SAVE_OPTS).optArg.argString = (char const*)(a) )
+ DESC(SAVE_OPTS).optArg.argString = (char const*)(a))
/*
* Interface defines not associated with particular options
*/
ntpqOptions.pzCurOpt = NULL)
#define START_OPT RESTART_OPT(1)
#define USAGE(c) (*ntpqOptions.pUsageProc)(&ntpqOptions, c)
-/* extracted from opthead.tlib near line 484 */
+/* extracted from opthead.tlib near line 497 */
#ifdef __cplusplus
extern "C" {
-.TH ntpq 1ntpqman "02 Jan 2013" "4.2.7p343" "User Commands"
+.TH ntpq 1ntpqman "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntpq-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:29 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:10:24 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpq-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntpq
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..." [ host ...]
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..." " " "[ host ...]"
.SH DESCRIPTION
+The
+.B
+utility program is used to query NTP servers which
+implement the standard NTP mode 6 control message formats defined
+in Appendix B of the NTPv3 specification RFC1305, requesting
+information about current state and/or changes in that state.
+The same formats are used in NTPv4, although some of the
+variables have changed and new ones added. The description on this
+page is for the NTPv4 variables.
+The program may be run either in interactive mode or controlled using
+command line arguments.
+Requests to read and write arbitrary
+variables can be assembled, with raw and pretty-printed output
+options being available.
+The
+.B
+utility can also obtain and print a
+list of peers in a common format by sending multiple queries to the
+server.
+If one or more request options is included on the command line
+when
+.B
+is executed, each of the requests will be sent
+to the NTP servers running on each of the hosts given as command
+line arguments, or on localhost by default.
+If no request options
+are given,
+.B
+will attempt to read commands from the
+standard input and execute these on the NTP server running on the
+first host given on the command line, again defaulting to localhost
+when no other host is specified.
+The
+.B
+utility will prompt for
+commands if the standard input is a terminal device.
+.B
+uses NTP mode 6 packets to communicate with the
+NTP server, and hence can be used to query any compatible server on
+the network which permits it.
+Note that since NTP is a UDP protocol
+this communication will be somewhat unreliable, especially over
+large distances in terms of network topology.
+The
+.B
+utility makes
+one attempt to retransmit requests, and will time requests out if
+the remote host is not heard from within a suitable timeout
+time.
+Specifying a
+command line option other than
+i
+or
+n
+will
+cause the specified query (queries) to be sent to the indicated
+host(s) immediately.
+Otherwise,
+.B
+will attempt to read
+interactive format commands from the standard input.
+.SS "Internal Commands"
+Interactive format commands consist of a keyword followed by zero
+to four arguments.
+Only enough characters of the full keyword to
+uniquely identify the command need be typed.
+A
+number of interactive format commands are executed entirely within
+the
+.B
+utility itself and do not result in NTP mode 6
+requests being sent to a server.
+These are described following.
+.TP
+.BR Ic ? Op Ar command_keyword
+.TP
+.BR Ic help Op Ar command_keyword
+A
+.Ql \&?
+by itself will print a list of all the command
+keywords known to this incarnation of
+.Nm .
+A
+.Ql \&?
+followed by a command keyword will print function and usage
+information about the command.
+This command is probably a better
+source of information about
+.Nm
+than this manual
+page.
+.TP
+.BR Ic addvars Ar variable_name Xo Op Ic =value
+.Ic ...
+.Xc
+.TP
+.BR Ic rmvars Ar variable_name Ic ...
+.TP
+.BR Ic clearvars
+The data carried by NTP mode 6 messages consists of a list of
+items of the form
+.Ql variable_name=value ,
+where the
+.Ql =value
+is ignored, and can be omitted,
+in requests to the server to read variables.
+The
+.Nm
+utility maintains an internal list in which data to be included in control
+messages can be assembled, and sent using the
+.Ic readlist
+and
+.Ic writelist
+commands described below.
+The
+.Ic addvars
+command allows variables and their optional values to be added to
+the list.
+If more than one variable is to be added, the list should
+be comma-separated and not contain white space.
+The
+.Ic rmvars
+command can be used to remove individual variables from the list,
+while the
+.Ic clearlist
+command removes all variables from the
+list.
+.TP
+.BR Ic authenticate Op yes | no
+Normally
+.Nm
+does not authenticate requests unless
+they are write requests.
+The command
+.Ql authenticate yes
+causes
+.Nm
+to send authentication with all requests it
+makes.
+Authenticated requests causes some servers to handle
+requests slightly differently, and can occasionally melt the CPU in
+fuzzballs if you turn authentication on before doing a
+.Ic peer
+display.
+The command
+.Ql authenticate
+causes
+.Nm
+to display whether or not
+.Nm
+is currently autheinticating requests.
+.TP
+.BR Ic cooked
+Causes output from query commands to be "cooked", so that
+variables which are recognized by
+.Nm
+will have their
+values reformatted for human consumption.
+Variables which
+.Nm
+thinks should have a decodable value but didn't are
+marked with a trailing
+.Ql \&? .
+.TP
+.BR Xo
+.Ic debug
+.Oo
+.Cm more |
+.Cm less |
+.Cm off
+.Oc
+.Xc
+With no argument, displays the current debug level.
+Otherwise, the debug level is changed to the indicated level.
+.TP
+.BR Ic delay Ar milliseconds
+Specify a time interval to be added to timestamps included in
+requests which require authentication.
+This is used to enable
+(unreliable) server reconfiguration over long delay network paths
+or between machines whose clocks are unsynchronized.
+Actually the
+server does not now require timestamps in authenticated requests,
+so this command may be obsolete.
+.TP
+.BR Ic host Ar hostname
+Set the host to which future queries will be sent.
+\fIhostname\fR
+may be either a host name or a numeric address.
+.TP
+.BR Ic hostnames Op Cm yes | Cm no
+If
+.Cm yes
+is specified, host names are printed in
+information displays.
+If
+.Cm no
+is specified, numeric
+addresses are printed instead.
+The default is
+.Cm yes ,
+unless
+modified using the command line
+n
+switch.
+.TP
+.BR Ic keyid Ar keyid
+This command allows the specification of a key number to be
+used to authenticate configuration requests.
+This must correspond
+to a key number the server has been configured to use for this
+purpose.
+.TP
+.BR Ic ntpversion Xo Oo
+.Cm 1 |
+.Cm 2 |
+.Cm 3 |
+.Cm 4
+.Oc
+.Xc
+Sets the NTP version number which
+.Nm
+claims in
+packets.
+Defaults to 3, and note that mode 6 control messages (and
+modes, for that matter) didn't exist in NTP version 1.
+There appear
+to be no servers left which demand version 1.
+With no argument, displays the current NTP version that will be used
+when communicating with servers.
+.TP
+.BR Ic quit
+Exit
+.Nm
+.TP
+.BR Ic passwd
+This command prompts you to type in a password (which will not
+be echoed) which will be used to authenticate configuration
+requests.
+The password must correspond to the key configured for
+use by the NTP server for this purpose if such requests are to be
+successful.
+.TP
+.BR Ic raw
+Causes all output from query commands is printed as received
+from the remote server.
+The only formating/interpretation done on
+the data is to transform nonascii data into a printable (but barely
+understandable) form.
+.TP
+.BR Ic timeout Ar milliseconds
+Specify a timeout period for responses to server queries.
+The
+default is about 5000 milliseconds.
+Note that since
+.Nm
+retries each query once after a timeout, the total waiting time for
+a timeout will be twice the timeout value set.
.SH "OPTIONS"
.TP
.BR \-4 ", " -\-ipv4
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTPQ 1ntpqmdoc User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntpq-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:34 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:10:30 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpq-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
[ host ...]
.Pp
.Sh DESCRIPTION
+The
+.Nm
+utility program is used to query NTP servers which
+implement the standard NTP mode 6 control message formats defined
+in Appendix B of the NTPv3 specification RFC1305, requesting
+information about current state and/or changes in that state.
+The same formats are used in NTPv4, although some of the
+variables have changed and new ones added. The description on this
+page is for the NTPv4 variables.
+The program may be run either in interactive mode or controlled using
+command line arguments.
+Requests to read and write arbitrary
+variables can be assembled, with raw and pretty-printed output
+options being available.
+The
+.Nm
+utility can also obtain and print a
+list of peers in a common format by sending multiple queries to the
+server.
+If one or more request options is included on the command line
+when
+.Nm
+is executed, each of the requests will be sent
+to the NTP servers running on each of the hosts given as command
+line arguments, or on localhost by default.
+If no request options
+are given,
+.Nm
+will attempt to read commands from the
+standard input and execute these on the NTP server running on the
+first host given on the command line, again defaulting to localhost
+when no other host is specified.
+The
+.Nm
+utility will prompt for
+commands if the standard input is a terminal device.
+.Nm
+uses NTP mode 6 packets to communicate with the
+NTP server, and hence can be used to query any compatible server on
+the network which permits it.
+Note that since NTP is a UDP protocol
+this communication will be somewhat unreliable, especially over
+large distances in terms of network topology.
+The
+.Nm
+utility makes
+one attempt to retransmit requests, and will time requests out if
+the remote host is not heard from within a suitable timeout
+time.
+Specifying a
+command line option other than
+.Fl i
+or
+.Fl n
+will
+cause the specified query (queries) to be sent to the indicated
+host(s) immediately.
+Otherwise,
+.Nm
+will attempt to read
+interactive format commands from the standard input.
+.Ss "Internal Commands"
+Interactive format commands consist of a keyword followed by zero
+to four arguments.
+Only enough characters of the full keyword to
+uniquely identify the command need be typed.
+A
+number of interactive format commands are executed entirely within
+the
+.Nm
+utility itself and do not result in NTP mode 6
+requests being sent to a server.
+These are described following.
+.Bl -tag -width "? [command_keyword]" -compact -offset indent
+.It Ic ? Op Ar command_keyword
+.It Ic help Op Ar command_keyword
+A
+.Ql \&?
+by itself will print a list of all the command
+keywords known to this incarnation of
+.Nm .
+A
+.Ql \&?
+followed by a command keyword will print function and usage
+information about the command.
+This command is probably a better
+source of information about
+.Nm
+than this manual
+page.
+.It Ic addvars Ar variable_name Xo Op Ic =value
+.Ic ...
+.Xc
+.It Ic rmvars Ar variable_name Ic ...
+.It Ic clearvars
+The data carried by NTP mode 6 messages consists of a list of
+items of the form
+.Ql variable_name=value ,
+where the
+.Ql =value
+is ignored, and can be omitted,
+in requests to the server to read variables.
+The
+.Nm
+utility maintains an internal list in which data to be included in control
+messages can be assembled, and sent using the
+.Ic readlist
+and
+.Ic writelist
+commands described below.
+The
+.Ic addvars
+command allows variables and their optional values to be added to
+the list.
+If more than one variable is to be added, the list should
+be comma-separated and not contain white space.
+The
+.Ic rmvars
+command can be used to remove individual variables from the list,
+while the
+.Ic clearlist
+command removes all variables from the
+list.
+.It Ic authenticate Op yes | no
+Normally
+.Nm
+does not authenticate requests unless
+they are write requests.
+The command
+.Ql authenticate yes
+causes
+.Nm
+to send authentication with all requests it
+makes.
+Authenticated requests causes some servers to handle
+requests slightly differently, and can occasionally melt the CPU in
+fuzzballs if you turn authentication on before doing a
+.Ic peer
+display.
+The command
+.Ql authenticate
+causes
+.Nm
+to display whether or not
+.Nm
+is currently autheinticating requests.
+.It Ic cooked
+Causes output from query commands to be "cooked", so that
+variables which are recognized by
+.Nm
+will have their
+values reformatted for human consumption.
+Variables which
+.Nm
+thinks should have a decodable value but didn't are
+marked with a trailing
+.Ql \&? .
+.It Xo
+.Ic debug
+.Oo
+.Cm more |
+.Cm less |
+.Cm off
+.Oc
+.Xc
+With no argument, displays the current debug level.
+Otherwise, the debug level is changed to the indicated level.
+.It Ic delay Ar milliseconds
+Specify a time interval to be added to timestamps included in
+requests which require authentication.
+This is used to enable
+(unreliable) server reconfiguration over long delay network paths
+or between machines whose clocks are unsynchronized.
+Actually the
+server does not now require timestamps in authenticated requests,
+so this command may be obsolete.
+.It Ic host Ar hostname
+Set the host to which future queries will be sent.
+.Ar hostname
+may be either a host name or a numeric address.
+.It Ic hostnames Op Cm yes | Cm no
+If
+.Cm yes
+is specified, host names are printed in
+information displays.
+If
+.Cm no
+is specified, numeric
+addresses are printed instead.
+The default is
+.Cm yes ,
+unless
+modified using the command line
+.Fl n
+switch.
+.It Ic keyid Ar keyid
+This command allows the specification of a key number to be
+used to authenticate configuration requests.
+This must correspond
+to a key number the server has been configured to use for this
+purpose.
+.It Ic ntpversion Xo Oo
+.Cm 1 |
+.Cm 2 |
+.Cm 3 |
+.Cm 4
+.Oc
+.Xc
+Sets the NTP version number which
+.Nm
+claims in
+packets.
+Defaults to 3, and note that mode 6 control messages (and
+modes, for that matter) didn't exist in NTP version 1.
+There appear
+to be no servers left which demand version 1.
+With no argument, displays the current NTP version that will be used
+when communicating with servers.
+.It Ic quit
+Exit
+.Nm
+.It Ic passwd
+This command prompts you to type in a password (which will not
+be echoed) which will be used to authenticate configuration
+requests.
+The password must correspond to the key configured for
+use by the NTP server for this purpose if such requests are to be
+successful.
+.It Ic raw
+Causes all output from query commands is printed as received
+from the remote server.
+The only formating/interpretation done on
+the data is to transform nonascii data into a printable (but barely
+understandable) form.
+.It Ic timeout Ar milliseconds
+Specify a timeout period for responses to server queries.
+The
+default is about 5000 milliseconds.
+Note that since
+.Nm
+retries each query once after a timeout, the total waiting time for
+a timeout will be twice the timeout value set.
+.El
.Sh "OPTIONS"
.Bl -tag
.It \-4 ", " -\-ipv4
and determine the performance of
<code>ntpd</code>, the NTP daemon.
- <p>This document applies to version 4.2.7p343 of <code>ntpq</code>.
+ <p>This document applies to version 4.2.7p344 of <code>ntpq</code>.
<ul class="menu">
<li><a accesskey="1" href="#ntpq-Description">ntpq Description</a>
used to select the program, defaulting to <span class="file">more</span>. Both will exit
with a status code of 0.
-<pre class="example">ntpq - standard NTP query program - Ver. 4.2.7p342
+<pre class="example">ntpq - standard NTP query program - Ver. 4.2.7p343
USAGE: ntpq [ -<flag> [<val>] | --<name>[{=| }<val>] ]... [ host ...]
Flg Arg Option-Name Description
-4 no ipv4 Force IPv4 DNS name resolution
-.TH ntpq @NTPQ_MS@ "02 Jan 2013" "4.2.7p343" "User Commands"
+.TH ntpq @NTPQ_MS@ "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntpq-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:29 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:10:24 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpq-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntpq
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..." [ host ...]
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..." " " "[ host ...]"
.SH DESCRIPTION
+The
+.B
+utility program is used to query NTP servers which
+implement the standard NTP mode 6 control message formats defined
+in Appendix B of the NTPv3 specification RFC1305, requesting
+information about current state and/or changes in that state.
+The same formats are used in NTPv4, although some of the
+variables have changed and new ones added. The description on this
+page is for the NTPv4 variables.
+The program may be run either in interactive mode or controlled using
+command line arguments.
+Requests to read and write arbitrary
+variables can be assembled, with raw and pretty-printed output
+options being available.
+The
+.B
+utility can also obtain and print a
+list of peers in a common format by sending multiple queries to the
+server.
+If one or more request options is included on the command line
+when
+.B
+is executed, each of the requests will be sent
+to the NTP servers running on each of the hosts given as command
+line arguments, or on localhost by default.
+If no request options
+are given,
+.B
+will attempt to read commands from the
+standard input and execute these on the NTP server running on the
+first host given on the command line, again defaulting to localhost
+when no other host is specified.
+The
+.B
+utility will prompt for
+commands if the standard input is a terminal device.
+.B
+uses NTP mode 6 packets to communicate with the
+NTP server, and hence can be used to query any compatible server on
+the network which permits it.
+Note that since NTP is a UDP protocol
+this communication will be somewhat unreliable, especially over
+large distances in terms of network topology.
+The
+.B
+utility makes
+one attempt to retransmit requests, and will time requests out if
+the remote host is not heard from within a suitable timeout
+time.
+Specifying a
+command line option other than
+i
+or
+n
+will
+cause the specified query (queries) to be sent to the indicated
+host(s) immediately.
+Otherwise,
+.B
+will attempt to read
+interactive format commands from the standard input.
+.SS "Internal Commands"
+Interactive format commands consist of a keyword followed by zero
+to four arguments.
+Only enough characters of the full keyword to
+uniquely identify the command need be typed.
+A
+number of interactive format commands are executed entirely within
+the
+.B
+utility itself and do not result in NTP mode 6
+requests being sent to a server.
+These are described following.
+.TP
+.BR Ic ? Op Ar command_keyword
+.TP
+.BR Ic help Op Ar command_keyword
+A
+.Ql \&?
+by itself will print a list of all the command
+keywords known to this incarnation of
+.Nm .
+A
+.Ql \&?
+followed by a command keyword will print function and usage
+information about the command.
+This command is probably a better
+source of information about
+.Nm
+than this manual
+page.
+.TP
+.BR Ic addvars Ar variable_name Xo Op Ic =value
+.Ic ...
+.Xc
+.TP
+.BR Ic rmvars Ar variable_name Ic ...
+.TP
+.BR Ic clearvars
+The data carried by NTP mode 6 messages consists of a list of
+items of the form
+.Ql variable_name=value ,
+where the
+.Ql =value
+is ignored, and can be omitted,
+in requests to the server to read variables.
+The
+.Nm
+utility maintains an internal list in which data to be included in control
+messages can be assembled, and sent using the
+.Ic readlist
+and
+.Ic writelist
+commands described below.
+The
+.Ic addvars
+command allows variables and their optional values to be added to
+the list.
+If more than one variable is to be added, the list should
+be comma-separated and not contain white space.
+The
+.Ic rmvars
+command can be used to remove individual variables from the list,
+while the
+.Ic clearlist
+command removes all variables from the
+list.
+.TP
+.BR Ic authenticate Op yes | no
+Normally
+.Nm
+does not authenticate requests unless
+they are write requests.
+The command
+.Ql authenticate yes
+causes
+.Nm
+to send authentication with all requests it
+makes.
+Authenticated requests causes some servers to handle
+requests slightly differently, and can occasionally melt the CPU in
+fuzzballs if you turn authentication on before doing a
+.Ic peer
+display.
+The command
+.Ql authenticate
+causes
+.Nm
+to display whether or not
+.Nm
+is currently autheinticating requests.
+.TP
+.BR Ic cooked
+Causes output from query commands to be "cooked", so that
+variables which are recognized by
+.Nm
+will have their
+values reformatted for human consumption.
+Variables which
+.Nm
+thinks should have a decodable value but didn't are
+marked with a trailing
+.Ql \&? .
+.TP
+.BR Xo
+.Ic debug
+.Oo
+.Cm more |
+.Cm less |
+.Cm off
+.Oc
+.Xc
+With no argument, displays the current debug level.
+Otherwise, the debug level is changed to the indicated level.
+.TP
+.BR Ic delay Ar milliseconds
+Specify a time interval to be added to timestamps included in
+requests which require authentication.
+This is used to enable
+(unreliable) server reconfiguration over long delay network paths
+or between machines whose clocks are unsynchronized.
+Actually the
+server does not now require timestamps in authenticated requests,
+so this command may be obsolete.
+.TP
+.BR Ic host Ar hostname
+Set the host to which future queries will be sent.
+\fIhostname\fR
+may be either a host name or a numeric address.
+.TP
+.BR Ic hostnames Op Cm yes | Cm no
+If
+.Cm yes
+is specified, host names are printed in
+information displays.
+If
+.Cm no
+is specified, numeric
+addresses are printed instead.
+The default is
+.Cm yes ,
+unless
+modified using the command line
+n
+switch.
+.TP
+.BR Ic keyid Ar keyid
+This command allows the specification of a key number to be
+used to authenticate configuration requests.
+This must correspond
+to a key number the server has been configured to use for this
+purpose.
+.TP
+.BR Ic ntpversion Xo Oo
+.Cm 1 |
+.Cm 2 |
+.Cm 3 |
+.Cm 4
+.Oc
+.Xc
+Sets the NTP version number which
+.Nm
+claims in
+packets.
+Defaults to 3, and note that mode 6 control messages (and
+modes, for that matter) didn't exist in NTP version 1.
+There appear
+to be no servers left which demand version 1.
+With no argument, displays the current NTP version that will be used
+when communicating with servers.
+.TP
+.BR Ic quit
+Exit
+.Nm
+.TP
+.BR Ic passwd
+This command prompts you to type in a password (which will not
+be echoed) which will be used to authenticate configuration
+requests.
+The password must correspond to the key configured for
+use by the NTP server for this purpose if such requests are to be
+successful.
+.TP
+.BR Ic raw
+Causes all output from query commands is printed as received
+from the remote server.
+The only formating/interpretation done on
+the data is to transform nonascii data into a printable (but barely
+understandable) form.
+.TP
+.BR Ic timeout Ar milliseconds
+Specify a timeout period for responses to server queries.
+The
+default is about 5000 milliseconds.
+Note that since
+.Nm
+retries each query once after a timeout, the total waiting time for
+a timeout will be twice the timeout value set.
.SH "OPTIONS"
.TP
.BR \-4 ", " -\-ipv4
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTPQ @NTPQ_MS@ User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntpq-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:34 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:10:30 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpq-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
[ host ...]
.Pp
.Sh DESCRIPTION
+The
+.Nm
+utility program is used to query NTP servers which
+implement the standard NTP mode 6 control message formats defined
+in Appendix B of the NTPv3 specification RFC1305, requesting
+information about current state and/or changes in that state.
+The same formats are used in NTPv4, although some of the
+variables have changed and new ones added. The description on this
+page is for the NTPv4 variables.
+The program may be run either in interactive mode or controlled using
+command line arguments.
+Requests to read and write arbitrary
+variables can be assembled, with raw and pretty-printed output
+options being available.
+The
+.Nm
+utility can also obtain and print a
+list of peers in a common format by sending multiple queries to the
+server.
+If one or more request options is included on the command line
+when
+.Nm
+is executed, each of the requests will be sent
+to the NTP servers running on each of the hosts given as command
+line arguments, or on localhost by default.
+If no request options
+are given,
+.Nm
+will attempt to read commands from the
+standard input and execute these on the NTP server running on the
+first host given on the command line, again defaulting to localhost
+when no other host is specified.
+The
+.Nm
+utility will prompt for
+commands if the standard input is a terminal device.
+.Nm
+uses NTP mode 6 packets to communicate with the
+NTP server, and hence can be used to query any compatible server on
+the network which permits it.
+Note that since NTP is a UDP protocol
+this communication will be somewhat unreliable, especially over
+large distances in terms of network topology.
+The
+.Nm
+utility makes
+one attempt to retransmit requests, and will time requests out if
+the remote host is not heard from within a suitable timeout
+time.
+Specifying a
+command line option other than
+.Fl i
+or
+.Fl n
+will
+cause the specified query (queries) to be sent to the indicated
+host(s) immediately.
+Otherwise,
+.Nm
+will attempt to read
+interactive format commands from the standard input.
+.Ss "Internal Commands"
+Interactive format commands consist of a keyword followed by zero
+to four arguments.
+Only enough characters of the full keyword to
+uniquely identify the command need be typed.
+A
+number of interactive format commands are executed entirely within
+the
+.Nm
+utility itself and do not result in NTP mode 6
+requests being sent to a server.
+These are described following.
+.Bl -tag -width "? [command_keyword]" -compact -offset indent
+.It Ic ? Op Ar command_keyword
+.It Ic help Op Ar command_keyword
+A
+.Ql \&?
+by itself will print a list of all the command
+keywords known to this incarnation of
+.Nm .
+A
+.Ql \&?
+followed by a command keyword will print function and usage
+information about the command.
+This command is probably a better
+source of information about
+.Nm
+than this manual
+page.
+.It Ic addvars Ar variable_name Xo Op Ic =value
+.Ic ...
+.Xc
+.It Ic rmvars Ar variable_name Ic ...
+.It Ic clearvars
+The data carried by NTP mode 6 messages consists of a list of
+items of the form
+.Ql variable_name=value ,
+where the
+.Ql =value
+is ignored, and can be omitted,
+in requests to the server to read variables.
+The
+.Nm
+utility maintains an internal list in which data to be included in control
+messages can be assembled, and sent using the
+.Ic readlist
+and
+.Ic writelist
+commands described below.
+The
+.Ic addvars
+command allows variables and their optional values to be added to
+the list.
+If more than one variable is to be added, the list should
+be comma-separated and not contain white space.
+The
+.Ic rmvars
+command can be used to remove individual variables from the list,
+while the
+.Ic clearlist
+command removes all variables from the
+list.
+.It Ic authenticate Op yes | no
+Normally
+.Nm
+does not authenticate requests unless
+they are write requests.
+The command
+.Ql authenticate yes
+causes
+.Nm
+to send authentication with all requests it
+makes.
+Authenticated requests causes some servers to handle
+requests slightly differently, and can occasionally melt the CPU in
+fuzzballs if you turn authentication on before doing a
+.Ic peer
+display.
+The command
+.Ql authenticate
+causes
+.Nm
+to display whether or not
+.Nm
+is currently autheinticating requests.
+.It Ic cooked
+Causes output from query commands to be "cooked", so that
+variables which are recognized by
+.Nm
+will have their
+values reformatted for human consumption.
+Variables which
+.Nm
+thinks should have a decodable value but didn't are
+marked with a trailing
+.Ql \&? .
+.It Xo
+.Ic debug
+.Oo
+.Cm more |
+.Cm less |
+.Cm off
+.Oc
+.Xc
+With no argument, displays the current debug level.
+Otherwise, the debug level is changed to the indicated level.
+.It Ic delay Ar milliseconds
+Specify a time interval to be added to timestamps included in
+requests which require authentication.
+This is used to enable
+(unreliable) server reconfiguration over long delay network paths
+or between machines whose clocks are unsynchronized.
+Actually the
+server does not now require timestamps in authenticated requests,
+so this command may be obsolete.
+.It Ic host Ar hostname
+Set the host to which future queries will be sent.
+.Ar hostname
+may be either a host name or a numeric address.
+.It Ic hostnames Op Cm yes | Cm no
+If
+.Cm yes
+is specified, host names are printed in
+information displays.
+If
+.Cm no
+is specified, numeric
+addresses are printed instead.
+The default is
+.Cm yes ,
+unless
+modified using the command line
+.Fl n
+switch.
+.It Ic keyid Ar keyid
+This command allows the specification of a key number to be
+used to authenticate configuration requests.
+This must correspond
+to a key number the server has been configured to use for this
+purpose.
+.It Ic ntpversion Xo Oo
+.Cm 1 |
+.Cm 2 |
+.Cm 3 |
+.Cm 4
+.Oc
+.Xc
+Sets the NTP version number which
+.Nm
+claims in
+packets.
+Defaults to 3, and note that mode 6 control messages (and
+modes, for that matter) didn't exist in NTP version 1.
+There appear
+to be no servers left which demand version 1.
+With no argument, displays the current NTP version that will be used
+when communicating with servers.
+.It Ic quit
+Exit
+.Nm
+.It Ic passwd
+This command prompts you to type in a password (which will not
+be echoed) which will be used to authenticate configuration
+requests.
+The password must correspond to the key configured for
+use by the NTP server for this purpose if such requests are to be
+successful.
+.It Ic raw
+Causes all output from query commands is printed as received
+from the remote server.
+The only formating/interpretation done on
+the data is to transform nonascii data into a printable (but barely
+understandable) form.
+.It Ic timeout Ar milliseconds
+Specify a timeout period for responses to server queries.
+The
+default is about 5000 milliseconds.
+Note that since
+.Nm
+retries each query once after a timeout, the total waiting time for
+a timeout will be twice the timeout value set.
+.El
.Sh "OPTIONS"
.Bl -tag
.It \-4 ", " -\-ipv4
#
# EDIT THIS FILE WITH CAUTION (invoke-ntpsnmpd.texi)
#
-# It has been AutoGen-ed January 2, 2013 at 02:20:49 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:10:45 PM by AutoGen 5.17.1pre11
# From the definitions ntpsnmpd-opts.def
# and the template file agtexi-cmd.tpl
@end ignore
@exampleindent 0
@example
-ntpsnmpd - NTP SNMP MIB agent - Ver. 4.2.7p343
+ntpsnmpd - NTP SNMP MIB agent - Ver. 4.2.7p344
USAGE: ntpsnmpd [ -<flag> [<val>] | --<name>[@{=| @}<val>] ]...
Flg Arg Option-Name Description
-n no nofork Do not fork
@subsection ntpsnmpd Usage
@code{ntpsnmpd}
currently uses a private MIB OID,
-@quoteleft{}enterprises.5597@quoteright{},
+@quoteleft{}enterprises.5597,@quoteright{}
which is the Meinberg top level OEM OID, and
@quoteleft{}99@quoteright{}
is the temporary working space for this project.
If you have
@code{snmpwalk(1)}
installed you can run
-.Dl
-%
-snmpwalk
--v2c
--c
-public
-localhost
-enterprises.5597.99
+@example
+% snmpwalk -v2c -c public localhost enterprises.5597.99
+@end example
to see a list of all currently supported NTP MIB objects
and their current values.
@node ntpsnmpd Notes
@subsection ntpsnmpd Notes
The following objects are currently supported:
-@table @samp
-@item Li
+@table @asis
+
+@item @code{ntpEntSoftwareName}
please fill me in...
-@item Li
+@item @code{ntpEntSoftwareVersion}
please fill me in...
-@item Li
+@item @code{ntpEntSoftwareVersionVal}
please fill me in...
-@item Li
+@item @code{ntpEntSoftwareVendor}
please fill me in...
-@item Li
+@item @code{ntpEntSystemType}
please fill me in...
-@item Li
+@item @code{ntpEntTimeResolution}
please fill me in...
-@item Li
+@item @code{ntpEntTimeResolutionVal}
please fill me in...
-@item Li
+@item @code{ntpEntTimePrecision}
please fill me in...
-@item Li
+@item @code{ntpEntTimePrecisionVal}
please fill me in...
-@item Li
+@item @code{ntpEntTimeDistance}
please fill me in...
@end table
This document corresponds to version @VERSION@ of NTP.
@node ntpsnmpd Authors
@subsection ntpsnmpd Authors
-1@*
+Heiko Gerstung@*
/*
* EDIT THIS FILE WITH CAUTION (ntpsnmpd-opts.c)
*
- * It has been AutoGen-ed January 2, 2013 at 02:20:37 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:10:33 PM by AutoGen 5.17.1pre11
* From the definitions ntpsnmpd-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This source file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* ntpsnmpd option static const strings
*/
static char const ntpsnmpd_opt_strs[1561] =
-/* 0 */ "ntpsnmpd 4.2.7p343\n"
+/* 0 */ "ntpsnmpd 4.2.7p344\n"
"Copyright (C) 1970-2013 The University of Delaware, all rights reserved.\n"
"This is free software. It is licensed for use, modification and\n"
"redistribution under the terms of the NTP License, copies of which\n"
/* 1360 */ "no-load-opts\0"
/* 1373 */ "no\0"
/* 1376 */ "NTPSNMPD\0"
-/* 1385 */ "ntpsnmpd - NTP SNMP MIB agent - Ver. 4.2.7p343\n"
+/* 1385 */ "ntpsnmpd - NTP SNMP MIB agent - Ver. 4.2.7p344\n"
"USAGE: %s [ -<flag> [<val>] | --<name>[{=| }<val>] ]...\n\0"
/* 1490 */ "$HOME\0"
/* 1496 */ ".\0"
/* 1498 */ ".ntprc\0"
/* 1505 */ "http://bugs.ntp.org, bugs@ntp.org\0"
/* 1539 */ "\n\n\0"
-/* 1542 */ "ntpsnmpd 4.2.7p343";
+/* 1542 */ "ntpsnmpd 4.2.7p344";
/*
* nofork option description:
#define zExplain (ntpsnmpd_opt_strs+1539)
#define zDetail (NULL)
#define zFullVersion (ntpsnmpd_opt_strs+1542)
-/* extracted from optcode.tlib near line 350 */
+/* extracted from optcode.tlib near line 353 */
#if defined(ENABLE_NLS)
# define OPTPROC_BASE OPTPROC_TRANSLATE
(void)pOptDesc;
(void)pOptions;
}
-/* extracted from optmain.tlib near line 48 */
+/* extracted from optmain.tlib near line 46 */
#if defined(TEST_NTPSNMPD_OPTS) /* TEST MAIN PROCEDURE: */
return res;
}
#endif /* defined TEST_NTPSNMPD_OPTS */
-/* extracted from optmain.tlib near line 1146 */
+/* extracted from optmain.tlib near line 1188 */
/**
* The directory containing the data associated with ntpsnmpd.
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#ifdef HAVE_DCGETTEXT
+# include <gettext.h>
+#endif
#include <autoopts/usage-txt.h>
-static char* AO_gettext(char const* pz);
-static void coerce_it(void** s);
+static char * AO_gettext(char const * pz);
+static void coerce_it(void ** s);
/**
- * AutoGen specific wrapper function for gettext.
- * It relies on the macro _() to convert from English to the target
- * language, then strdup-duplicates the result string.
+ * AutoGen specific wrapper function for gettext. It relies on the macro _()
+ * to convert from English to the target language, then strdup-duplicates the
+ * result string. It tries the "libopts" domain first, then whatever has been
+ * set via the \a textdomain(3) call.
*
* @param[in] pz the input text used as a lookup key.
* @returns the translated text (if there is one),
* or the original text (if not).
*/
static char *
-AO_gettext(char const* pz)
+AO_gettext(char const * pz)
{
- char* pzRes;
+ char * res;
if (pz == NULL)
return NULL;
- pzRes = _(pz);
- if (pzRes == pz)
- return pzRes;
- pzRes = strdup(pzRes);
- if (pzRes == NULL) {
+#ifdef HAVE_DCGETTEXT
+ /*
+ * While processing the option_xlateable_txt data, try to use the
+ * "libopts" domain. Once we switch to the option descriptor data,
+ * do *not* use that domain.
+ */
+ if (option_xlateable_txt.field_ct != 0) {
+ res = dgettext("libopts", pz);
+ if (res == pz)
+ res = (char *)(void *)_(pz);
+ } else
+ res = (char *)(void *)_(pz);
+#else
+ res = (char *)(void *)_(pz);
+#endif
+ if (res == pz)
+ return res;
+ res = strdup(res);
+ if (res == NULL) {
fputs(_("No memory for duping translated strings\n"), stderr);
exit(NTPSNMPD_EXIT_FAILURE);
}
- return pzRes;
+ return res;
}
-static void coerce_it(void** s) { *s = AO_gettext(*s);
+/**
+ * All the pointers we use are marked "* const", but they are stored in
+ * writable memory. Coerce the mutability and set the pointer.
+ */
+static void coerce_it(void ** s) { *s = AO_gettext(*s);
}
/**
static void
translate_option_strings(void)
{
- tOptions * const pOpt = &ntpsnmpdOptions;
+ tOptions * const opts = &ntpsnmpdOptions;
/*
* Guard against re-translation. It won't work. The strings will have
* been changed by the first pass through this code. One shot only.
*/
- if (option_usage_text.field_ct != 0) {
+ if (option_xlateable_txt.field_ct != 0) {
/*
* Do the translations. The first pointer follows the field count
* field. The field count field is the size of a pointer.
*/
- tOptDesc * pOD = pOpt->pOptDesc;
- char ** ppz = (char**)(void*)&(option_usage_text);
- int ix = option_usage_text.field_ct;
+ tOptDesc * od = opts->pOptDesc;
+ char ** ppz = (char**)(void*)&(option_xlateable_txt);
+ int ix = option_xlateable_txt.field_ct;
do {
- ppz++;
+ ppz++; /* skip over field_ct */
*ppz = AO_gettext(*ppz);
} while (--ix > 0);
-
- coerce_it((void*)&(pOpt->pzCopyright));
- coerce_it((void*)&(pOpt->pzCopyNotice));
- coerce_it((void*)&(pOpt->pzFullVersion));
- coerce_it((void*)&(pOpt->pzUsageTitle));
- coerce_it((void*)&(pOpt->pzExplain));
- coerce_it((void*)&(pOpt->pzDetail));
- coerce_it((void*)&(pOpt->pzPackager));
- option_usage_text.field_ct = 0;
-
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++)
- coerce_it((void*)&(pOD->pzText));
+ /* prevent re-translation and disable "libopts" domain lookup */
+ option_xlateable_txt.field_ct = 0;
+
+ coerce_it((void*)&(opts->pzCopyright));
+ coerce_it((void*)&(opts->pzCopyNotice));
+ coerce_it((void*)&(opts->pzFullVersion));
+ coerce_it((void*)&(opts->pzUsageTitle));
+ coerce_it((void*)&(opts->pzExplain));
+ coerce_it((void*)&(opts->pzDetail));
+ coerce_it((void*)&(opts->pzPackager));
+
+ for (ix = opts->optCt; ix > 0; ix--, od++)
+ coerce_it((void*)&(od->pzText));
}
- if ((pOpt->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
- tOptDesc * pOD = pOpt->pOptDesc;
+ if ((opts->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
+ tOptDesc * od = opts->pOptDesc;
int ix;
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++) {
- coerce_it((void*)&(pOD->pz_Name));
- coerce_it((void*)&(pOD->pz_DisableName));
- coerce_it((void*)&(pOD->pz_DisablePfx));
+ for (ix = opts->optCt; ix > 0; ix--, od++) {
+ coerce_it((void*)&(od->pz_Name));
+ coerce_it((void*)&(od->pz_DisableName));
+ coerce_it((void*)&(od->pz_DisablePfx));
}
- /* prevent re-translation */
ntpsnmpdOptions.fOptSet |= OPTPROC_NXLAT_OPT_CFG | OPTPROC_NXLAT_OPT;
}
}
/*
* EDIT THIS FILE WITH CAUTION (ntpsnmpd-opts.h)
*
- * It has been AutoGen-ed January 2, 2013 at 02:20:37 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:10:33 PM by AutoGen 5.17.1pre11
* From the definitions ntpsnmpd-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This header file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* tolerable version is at least as old as what was current when the header
* template was released.
*/
-#define AO_TEMPLATE_VERSION 147461
+#define AO_TEMPLATE_VERSION 151552
#if (AO_TEMPLATE_VERSION < OPTIONS_MINIMUM_VERSION) \
|| (AO_TEMPLATE_VERSION > OPTIONS_STRUCT_VERSION)
# error option template version mismatches autoopts/options.h header
} teOptIndex;
#define OPTION_CT 8
-#define NTPSNMPD_VERSION "4.2.7p343"
-#define NTPSNMPD_FULL_VERSION "ntpsnmpd 4.2.7p343"
+#define NTPSNMPD_VERSION "4.2.7p344"
+#define NTPSNMPD_FULL_VERSION "ntpsnmpd 4.2.7p344"
/*
* Interface defines for all options. Replace "n" with the UPPER_CASED
* Enumeration of ntpsnmpd exit codes
*/
typedef enum {
- NTPSNMPD_EXIT_SUCCESS = 0,
- NTPSNMPD_EXIT_FAILURE = 1,
- NTPSNMPD_EXIT_NO_CONFIG_INPUT = 66,
- NTPSNMPD_EXIT_LIBOPTS_FAILURE = 70
+ NTPSNMPD_EXIT_SUCCESS = 0,
+ NTPSNMPD_EXIT_FAILURE = 1,
+ NTPSNMPD_EXIT_USAGE_ERROR = 64,
+ NTPSNMPD_EXIT_NO_CONFIG_INPUT = 66,
+ NTPSNMPD_EXIT_LIBOPTS_FAILURE = 70
} ntpsnmpd_exit_code_t;
/*
* Make sure there are no #define name conflicts with the option names
#define SET_OPT_SAVE_OPTS(a) STMTS( \
DESC(SAVE_OPTS).fOptState &= OPTST_PERSISTENT_MASK; \
DESC(SAVE_OPTS).fOptState |= OPTST_SET; \
- DESC(SAVE_OPTS).optArg.argString = (char const*)(a) )
+ DESC(SAVE_OPTS).optArg.argString = (char const*)(a))
/*
* Interface defines not associated with particular options
*/
ntpsnmpdOptions.pzCurOpt = NULL)
#define START_OPT RESTART_OPT(1)
#define USAGE(c) (*ntpsnmpdOptions.pUsageProc)(&ntpsnmpdOptions, c)
-/* extracted from opthead.tlib near line 484 */
+/* extracted from opthead.tlib near line 497 */
#ifdef __cplusplus
extern "C" {
-.TH ntpsnmpd 1ntpsnmpdman "02 Jan 2013" "4.2.7p343" "User Commands"
+.TH ntpsnmpd 1ntpsnmpdman "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntpsnmpd-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:45 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:10:41 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpsnmpd-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntpsnmpd
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..."
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..."
.PP
All arguments must be options.
.PP
.SH DESCRIPTION
+.B
+is an SNMP MIB agent designed to interface with
+.Xr ntpd 1ntpdmdoc .
.SH "OPTIONS"
.TP
.BR \-n ", " -\-nofork
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.SH USAGE
+.B
+currently uses a private MIB OID,
+.Ql enterprises.5597 ,
+which is the Meinberg top level OEM OID, and
+.Ql 99
+is the temporary working space for this project.
+The final OID has to be registered with IANA
+and this is done by the RFC Editor
+when the NTPv4 MIB RFC is standardized.
+.PP
+If you have
+.Xr snmpwalk 1
+installed you can run
+.Dl % snmpwalk -v2c -c public localhost enterprises.5597.99
+to see a list of all currently supported NTP MIB objects
+and their current values.
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH "FILES"
libopts had an internal operational error. Please report
it to autogen-users@lists.sourceforge.net. Thank you.
.SH AUTHORS
+.An "Heiko Gerstung"
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+The following objects are currently supported:
+.PP
+.TP
+.BR Li ntpEntSoftwareName
+please fill me in...
+.TP
+.BR Li ntpEntSoftwareVersion
+please fill me in...
+.TP
+.BR Li ntpEntSoftwareVersionVal
+please fill me in...
+.TP
+.BR Li ntpEntSoftwareVendor
+please fill me in...
+.TP
+.BR Li ntpEntSystemType
+please fill me in...
+.TP
+.BR Li ntpEntTimeResolution
+please fill me in...
+.TP
+.BR Li ntpEntTimeResolutionVal
+please fill me in...
+.TP
+.BR Li ntpEntTimePrecision
+please fill me in...
+.TP
+.BR Li ntpEntTimePrecisionVal
+please fill me in...
+.TP
+.BR Li ntpEntTimeDistance
+please fill me in...
+.PP
+This document corresponds to version @VERSION@ of NTP.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntpsnmpd\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTPSNMPD 1ntpsnmpdmdoc User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntpsnmpd-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:51 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:10:47 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpsnmpd-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
All arguments must be options.
.Pp
.Sh DESCRIPTION
+.Nm
+is an SNMP MIB agent designed to interface with
+.Xr ntpd 1ntpdmdoc .
.Sh "OPTIONS"
.Bl -tag
.It \-n ", " -\-nofork
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.Sh USAGE
+.Nm
+currently uses a private MIB OID,
+.Ql enterprises.5597 ,
+which is the Meinberg top level OEM OID, and
+.Ql 99
+is the temporary working space for this project.
+The final OID has to be registered with IANA
+and this is done by the RFC Editor
+when the NTPv4 MIB RFC is standardized.
+.Pp
+If you have
+.Xr snmpwalk 1
+installed you can run
+.Dl % snmpwalk -v2c -c public localhost enterprises.5597.99
+to see a list of all currently supported NTP MIB objects
+and their current values.
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh "FILES"
it to autogen-users@lists.sourceforge.net. Thank you.
.El
.Sh AUTHORS
+.An "Heiko Gerstung"
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+The following objects are currently supported:
+.Pp
+.Bl -tag -width ".Li ntpEntSoftwareVersionVal" -compact -offset indent
+.It Li ntpEntSoftwareName
+please fill me in...
+.It Li ntpEntSoftwareVersion
+please fill me in...
+.It Li ntpEntSoftwareVersionVal
+please fill me in...
+.It Li ntpEntSoftwareVendor
+please fill me in...
+.It Li ntpEntSystemType
+please fill me in...
+.It Li ntpEntTimeResolution
+please fill me in...
+.It Li ntpEntTimeResolutionVal
+please fill me in...
+.It Li ntpEntTimePrecision
+please fill me in...
+.It Li ntpEntTimePrecisionVal
+please fill me in...
+.It Li ntpEntTimeDistance
+please fill me in...
+.El
+.Pp
+This document corresponds to version @VERSION@ of NTP.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntpsnmpd\fP
option definitions.
<p>The <code>ntpsnmpd</code> utility program is used to monitor NTP daemon <code>ntpd</code>
operations and determine performance. It uses the standard NTP mode 6 control
- <p>This document applies to version 4.2.7p343 of <code>ntpsnmpd</code>.
+ <p>This document applies to version 4.2.7p344 of <code>ntpsnmpd</code>.
<ul class="menu">
<li><a accesskey="1" href="#ntpsnmpd-Description">ntpsnmpd Description</a>: Description
-.TH ntpsnmpd @NTPSNMPD_MS@ "02 Jan 2013" "4.2.7p343" "User Commands"
+.TH ntpsnmpd @NTPSNMPD_MS@ "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntpsnmpd-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:45 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:10:41 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpsnmpd-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntpsnmpd
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..."
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..."
.PP
All arguments must be options.
.PP
.SH DESCRIPTION
+.B
+is an SNMP MIB agent designed to interface with
+.Xr ntpd @NTPD_MS@ .
.SH "OPTIONS"
.TP
.BR \-n ", " -\-nofork
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.SH USAGE
+.B
+currently uses a private MIB OID,
+.Ql enterprises.5597 ,
+which is the Meinberg top level OEM OID, and
+.Ql 99
+is the temporary working space for this project.
+The final OID has to be registered with IANA
+and this is done by the RFC Editor
+when the NTPv4 MIB RFC is standardized.
+.PP
+If you have
+.Xr snmpwalk 1
+installed you can run
+.Dl % snmpwalk -v2c -c public localhost enterprises.5597.99
+to see a list of all currently supported NTP MIB objects
+and their current values.
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH "FILES"
libopts had an internal operational error. Please report
it to autogen-users@lists.sourceforge.net. Thank you.
.SH AUTHORS
+.An "Heiko Gerstung"
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+The following objects are currently supported:
+.PP
+.TP
+.BR Li ntpEntSoftwareName
+please fill me in...
+.TP
+.BR Li ntpEntSoftwareVersion
+please fill me in...
+.TP
+.BR Li ntpEntSoftwareVersionVal
+please fill me in...
+.TP
+.BR Li ntpEntSoftwareVendor
+please fill me in...
+.TP
+.BR Li ntpEntSystemType
+please fill me in...
+.TP
+.BR Li ntpEntTimeResolution
+please fill me in...
+.TP
+.BR Li ntpEntTimeResolutionVal
+please fill me in...
+.TP
+.BR Li ntpEntTimePrecision
+please fill me in...
+.TP
+.BR Li ntpEntTimePrecisionVal
+please fill me in...
+.TP
+.BR Li ntpEntTimeDistance
+please fill me in...
+.PP
+This document corresponds to version @VERSION@ of NTP.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntpsnmpd\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTPSNMPD @NTPSNMPD_MS@ User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntpsnmpd-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:20:51 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:10:47 PM by AutoGen 5.17.1pre11
.\" From the definitions ntpsnmpd-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
All arguments must be options.
.Pp
.Sh DESCRIPTION
+.Nm
+is an SNMP MIB agent designed to interface with
+.Xr ntpd @NTPD_MS@ .
.Sh "OPTIONS"
.Bl -tag
.It \-n ", " -\-nofork
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.Sh USAGE
+.Nm
+currently uses a private MIB OID,
+.Ql enterprises.5597 ,
+which is the Meinberg top level OEM OID, and
+.Ql 99
+is the temporary working space for this project.
+The final OID has to be registered with IANA
+and this is done by the RFC Editor
+when the NTPv4 MIB RFC is standardized.
+.Pp
+If you have
+.Xr snmpwalk 1
+installed you can run
+.Dl % snmpwalk -v2c -c public localhost enterprises.5597.99
+to see a list of all currently supported NTP MIB objects
+and their current values.
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh "FILES"
it to autogen-users@lists.sourceforge.net. Thank you.
.El
.Sh AUTHORS
+.An "Heiko Gerstung"
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+The following objects are currently supported:
+.Pp
+.Bl -tag -width ".Li ntpEntSoftwareVersionVal" -compact -offset indent
+.It Li ntpEntSoftwareName
+please fill me in...
+.It Li ntpEntSoftwareVersion
+please fill me in...
+.It Li ntpEntSoftwareVersionVal
+please fill me in...
+.It Li ntpEntSoftwareVendor
+please fill me in...
+.It Li ntpEntSystemType
+please fill me in...
+.It Li ntpEntTimeResolution
+please fill me in...
+.It Li ntpEntTimeResolutionVal
+please fill me in...
+.It Li ntpEntTimePrecision
+please fill me in...
+.It Li ntpEntTimePrecisionVal
+please fill me in...
+.It Li ntpEntTimeDistance
+please fill me in...
+.El
+.Pp
+This document corresponds to version @VERSION@ of NTP.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntpsnmpd\fP
option definitions.
# - Numeric values increment
# - empty 'increments' to 1
# - NEW 'increments' to empty
-point=343
+point=344
### betapoint is normally modified by script.
# ntp-stable Beta number (betapoint)
#
# EDIT THIS FILE WITH CAUTION (invoke-ntp-wait.texi)
#
-# It has been AutoGen-ed January 1, 2013 at 11:31:23 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:06:56 PM by AutoGen 5.17.1pre11
# From the definitions ntp-wait-opts.def
# and the template file agtexi-cmd.tpl
@end ignore
@code{ntp-wait}
will send at most
-@code{num-tries} queries to
+@kbd{num-tries}
+queries to
@code{ntpd(8)},
sleeping for
-@code{secs-between-tries} after each status return that says
+@kbd{secs-between-tries}
+after each status return that says
@code{ntpd(8)}
has not yet produced a synchronized and stable system clock.
@code{ntp-wait}
will do this quietly, unless the
-@code{-v} flag is provided.
+@code{-v}
+flag is provided.
This section was generated by @strong{AutoGen},
using the @code{agtexi-cmd} template and the option descriptions for the @code{ntp-wait} program.
@exampleindent 0
@example
-/deacon/backroom/snaps/ntp-dev/A.snap/scripts/ntp-wait version [unknown] calling Getopt::Std::getopts (version 1.05 [paranoid]),
+/backroom/snaps/ntp-dev/A.snap/scripts/ntp-wait version [unknown] calling Getopt::Std::getopts (version 1.05 [paranoid]),
running under Perl version 5.8.8.
Usage: ntp-wait [-OPTIONS [-MORE_OPTIONS]] [--] [PROGRAM_ARG1 ...]
@end table
@node ntp-wait Authors
@subsection ntp-wait Authors
-1@*
+Harlan Stenn@*
@node ntp-wait Notes
@subsection ntp-wait Notes
This document corresponds to version @VERSION@ of NTP.
-.TH ntp-wait 1ntp-waitman "01 Jan 2013" "ntp (4.2.7p343)" "User Commands"
+.TH ntp-wait 1ntp-waitman "03 Jan 2013" "ntp (4.2.7p344)" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntp-wait-opts.man)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:31:18 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:06:52 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp-wait-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntp-wait
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..."
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..."
.PP
All arguments must be options.
.PP
.SH DESCRIPTION
+.B
+will send at most
+\fInum-tries\fR
+queries to
+.Xr ntpd 8 ,
+sleeping for
+\fIsecs-between-tries\fR
+after each status return that says
+.Xr ntpd 8
+has not yet produced a synchronized and stable system clock.
+.PP
+.B
+will do this quietly, unless the
+v
+flag is provided.
.SH "OPTIONS"
.TP
.BR \-n " \fInum\-tries\fP, " \-\- "=" \fInum\-tries\fP
.BR 1 " (EXIT_FAILURE)"
The operation failed or the command syntax was not valid.
.SH AUTHORS
+.An "Harlan Stenn"
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntp-wait\fP
option definitions.
-.Dd January 1 2013
+.Dd January 3 2013
.Dt NTP_WAIT 1ntp-waitmdoc User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntp-wait-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:31:27 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:06:58 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp-wait-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
All arguments must be options.
.Pp
.Sh DESCRIPTION
+.Nm
+will send at most
+.Ar num-tries
+queries to
+.Xr ntpd 8 ,
+sleeping for
+.Ar secs-between-tries
+after each status return that says
+.Xr ntpd 8
+has not yet produced a synchronized and stable system clock.
+.Pp
+.Nm
+will do this quietly, unless the
+.Fl v
+flag is provided.
.Sh "OPTIONS"
.Bl -tag
.It \-n " \fInum\-tries\fP, " \-\- "=" \fInum\-tries\fP
The operation failed or the command syntax was not valid.
.El
.Sh AUTHORS
+.An "Harlan Stenn"
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntp-wait\fP
option definitions.
and only then start any applicaitons (like database servers) that require
accurate and stable time.
- <p>This document applies to version 4.2.7p343 of <code>ntp-wait</code>.
+ <p>This document applies to version 4.2.7p344 of <code>ntp-wait</code>.
<div class="shortcontents">
<h2>Short Contents</h2>
<p><code>ntp-wait</code>
will send at most
-<code>num-tries</code> queries to
+<kbd>num-tries</kbd>
+queries to
<code>ntpd(8)</code>,
sleeping for
-<code>secs-between-tries</code> after each status return that says
+<kbd>secs-between-tries</kbd>
+after each status return that says
<code>ntpd(8)</code>
has not yet produced a synchronized and stable system clock.
<p><code>ntp-wait</code>
will do this quietly, unless the
-<code>-v</code> flag is provided.
+<code>-v</code>
+flag is provided.
<p>This section was generated by <strong>AutoGen</strong>,
using the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntp-wait</code> program.
used to select the program, defaulting to <span class="file">more</span>. Both will exit
with a status code of 0.
-<pre class="example">/deacon/backroom/snaps/ntp-dev/A.snap/scripts/ntp-wait version [unknown] calling Getopt::Std::getopts (version 1.05 [paranoid]),
+<pre class="example">/backroom/snaps/ntp-dev/A.snap/scripts/ntp-wait version [unknown] calling Getopt::Std::getopts (version 1.05 [paranoid]),
running under Perl version 5.8.8.
Usage: ntp-wait [-OPTIONS [-MORE_OPTIONS]] [--] [PROGRAM_ARG1 ...]
<h4 class="subsection">ntp-wait Authors</h4>
-<p>1<br>
+<p>Harlan Stenn<br>
<div class="node">
<p><hr>
<a name="ntp_002dwait-Notes"></a>Previous: <a rel="previous" accesskey="p" href="#ntp_002dwait-Authors">ntp-wait Authors</a>,
-.TH ntp-wait @NTP_WAIT_MS@ "01 Jan 2013" "ntp (4.2.7p343)" "User Commands"
+.TH ntp-wait @NTP_WAIT_MS@ "03 Jan 2013" "ntp (4.2.7p344)" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntp-wait-opts.man)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:31:18 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:06:52 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp-wait-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntp-wait
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..."
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..."
.PP
All arguments must be options.
.PP
.SH DESCRIPTION
+.B
+will send at most
+\fInum-tries\fR
+queries to
+.Xr ntpd 8 ,
+sleeping for
+\fIsecs-between-tries\fR
+after each status return that says
+.Xr ntpd 8
+has not yet produced a synchronized and stable system clock.
+.PP
+.B
+will do this quietly, unless the
+v
+flag is provided.
.SH "OPTIONS"
.TP
.BR \-n " \fInum\-tries\fP, " \-\- "=" \fInum\-tries\fP
.BR 1 " (EXIT_FAILURE)"
The operation failed or the command syntax was not valid.
.SH AUTHORS
+.An "Harlan Stenn"
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntp-wait\fP
option definitions.
-.Dd January 1 2013
+.Dd January 3 2013
.Dt NTP_WAIT @NTP_WAIT_MS@ User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntp-wait-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 1, 2013 at 11:31:27 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:06:58 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp-wait-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
All arguments must be options.
.Pp
.Sh DESCRIPTION
+.Nm
+will send at most
+.Ar num-tries
+queries to
+.Xr ntpd 8 ,
+sleeping for
+.Ar secs-between-tries
+after each status return that says
+.Xr ntpd 8
+has not yet produced a synchronized and stable system clock.
+.Pp
+.Nm
+will do this quietly, unless the
+.Fl v
+flag is provided.
.Sh "OPTIONS"
.Bl -tag
.It \-n " \fInum\-tries\fP, " \-\- "=" \fInum\-tries\fP
The operation failed or the command syntax was not valid.
.El
.Sh AUTHORS
+.An "Harlan Stenn"
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntp-wait\fP
option definitions.
#
# EDIT THIS FILE WITH CAUTION (invoke-sntp.texi)
#
-# It has been AutoGen-ed January 2, 2013 at 02:21:31 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:11:33 PM by AutoGen 5.17.1pre11
# From the definitions sntp-opts.def
# and the template file agtexi-cmd.tpl
@end ignore
can be used as an SNTP client to query a NTP or SNTP server and either display
the time or set the local system's time (given suitable privilege). It can be
run as an interactive command or from a
-@code{cron} job.
+@code{cron}
+job.
NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol)
are defined and described by RFC 5905.
The default is to write the estimated correct local date and time (i.e. not
UTC) to the standard output in a format like:
-@code{'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'}
+@code{'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'}
+
where the
-@code{'(+0800)'} means that to get to UTC from the reported local time one must
+@code{'(+0800)'}
+means that to get to UTC from the reported local time one must
add 8 hours and 0 minutes,
the
-@code{'+4.567'} indicates the local clock is 4.567 seconds behind the correct time
+@code{'+4.567'}
+indicates the local clock is 4.567 seconds behind the correct time
(so 4.567 seconds must be added to the local clock to get it to be correct).
Note that the number of decimals printed for this value will change
based on the reported precision of the server.
-@code{'+/- 0.089'} is the reported
-@emph{synchronizationdistance}
+@code{'+/- 0.089'}
+is the reported
+@emph{ synchronization distance}
(in seconds), which represents the maximum error due to all causes.
If the server does not report valid data needed to calculate the
synchronization distance, this will be reported as
-@code{'+/- ?'}. If the
-@emph{host}
+@code{'+/- ?'}.
+If the
+@emph{ host}
is different from the
-@emph{IP},
+@emph{ IP,}
both will be displayed.
Otherwise, only the
-@emph{IP}
+@emph{ IP}
is displayed.
Finally, the
-@emph{stratum}
+@emph{ stratum}
of the host is reported.
This section was generated by @strong{AutoGen},
@exampleindent 0
@example
-sntp - standard Simple Network Time Protocol client program - Ver. 4.2.7p343
+sntp - standard Simple Network Time Protocol client program - Ver. 4.2.7p344
USAGE: sntp [ -<flag> [<val>] | --<name>[@{=| @}<val>] ]... \
[ hostname-or-IP ...]
Flg Arg Option-Name Description
@end table
@node sntp Usage
@subsection sntp Usage
-@table @samp
-@item Li
+@table @asis
+
+@item @code{sntp ntpserver.somewhere}
is the simplest use of this program
and can be run as an unprivileged command
to check the current time and error in the local clock.
-@item Li
+@item @code{sntp -a ntpserver.somewhere}
With suitable privilege,
run as a command
or from a
@code{cron(8)}
job,
-@code{sntp -a} will reset the local clock from a synchronized specified server,
+@code{sntp -a}
+will reset the local clock from a synchronized specified server,
like the (deprecated)
@code{ntpdate(1ntpdatemdoc)},
or
@end table
@node sntp Authors
@subsection sntp Authors
-1@*1@*1@*
+Johannes Maximilian Kuehn@*
+Harlan Stenn@*
+Dave Hart@*
@node sntp Notes
@subsection sntp Notes
This document corresponds to version @VERSION@ of
/*
* EDIT THIS FILE WITH CAUTION (sntp-opts.c)
*
- * It has been AutoGen-ed January 1, 2013 at 11:25:30 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:02:56 PM by AutoGen 5.17.1pre11
* From the definitions sntp-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This source file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* sntp option static const strings
*/
static char const sntp_opt_strs[2500] =
-/* 0 */ "sntp 4.2.7p343\n"
+/* 0 */ "sntp 4.2.7p344\n"
"Copyright (C) 1970-2013 The University of Delaware, all rights reserved.\n"
"This is free software. It is licensed for use, modification and\n"
"redistribution under the terms of the NTP License, copies of which\n"
/* 2244 */ "LOAD_OPTS\0"
/* 2254 */ "no-load-opts\0"
/* 2267 */ "SNTP\0"
-/* 2272 */ "sntp - standard Simple Network Time Protocol client program - Ver. 4.2.7p343\n"
+/* 2272 */ "sntp - standard Simple Network Time Protocol client program - Ver. 4.2.7p344\n"
"USAGE: %s [ -<flag> [<val>] | --<name>[{=| }<val>] ]... \\\n"
"\t\t[ hostname-or-IP ...]\n\0"
/* 2433 */ "$HOME\0"
/* 2441 */ ".ntprc\0"
/* 2448 */ "http://bugs.ntp.org, bugs@ntp.org\0"
/* 2482 */ "\n\n\0"
-/* 2485 */ "sntp 4.2.7p343";
+/* 2485 */ "sntp 4.2.7p344";
/*
* ipv4 option description with
#define zExplain (sntp_opt_strs+2482)
#define zDetail (NULL)
#define zFullVersion (sntp_opt_strs+2485)
-/* extracted from optcode.tlib near line 350 */
+/* extracted from optcode.tlib near line 353 */
#if defined(ENABLE_NLS)
# define OPTPROC_BASE OPTPROC_TRANSLATE
static void
doOptDebug_Level(tOptions* pOptions, tOptDesc* pOptDesc)
{
+ /*
+ * Be sure the flag-code[0] handles special values for the options pointer
+ * viz. (poptions <= OPTPROC_EMIT_LIMIT) *and also* the special flag bit
+ * ((poptdesc->fOptState & OPTST_RESET) != 0) telling the option to
+ * reset its state.
+ */
/* extracted from debug-opt.def, line 15 */
OPT_VALUE_SET_DEBUG_LEVEL++;
(void)pOptDesc;
option_usage_fp = stderr;
-emit_ranges:
+ emit_ranges:
optionShowRange(pOptions, pOptDesc, (void *)rng, 1);
}
option_usage_fp = stderr;
-emit_ranges:
+ emit_ranges:
optionShowRange(pOptions, pOptDesc, (void *)rng, 1);
}
-/* extracted from optmain.tlib near line 48 */
+/* extracted from optmain.tlib near line 46 */
#if defined(TEST_SNTP_OPTS) /* TEST MAIN PROCEDURE: */
return res;
}
#endif /* defined TEST_SNTP_OPTS */
-/* extracted from optmain.tlib near line 1146 */
+/* extracted from optmain.tlib near line 1188 */
/**
* The directory containing the data associated with sntp.
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#ifdef HAVE_DCGETTEXT
+# include <gettext.h>
+#endif
#include <autoopts/usage-txt.h>
-static char* AO_gettext(char const* pz);
-static void coerce_it(void** s);
+static char * AO_gettext(char const * pz);
+static void coerce_it(void ** s);
/**
- * AutoGen specific wrapper function for gettext.
- * It relies on the macro _() to convert from English to the target
- * language, then strdup-duplicates the result string.
+ * AutoGen specific wrapper function for gettext. It relies on the macro _()
+ * to convert from English to the target language, then strdup-duplicates the
+ * result string. It tries the "libopts" domain first, then whatever has been
+ * set via the \a textdomain(3) call.
*
* @param[in] pz the input text used as a lookup key.
* @returns the translated text (if there is one),
* or the original text (if not).
*/
static char *
-AO_gettext(char const* pz)
+AO_gettext(char const * pz)
{
- char* pzRes;
+ char * res;
if (pz == NULL)
return NULL;
- pzRes = _(pz);
- if (pzRes == pz)
- return pzRes;
- pzRes = strdup(pzRes);
- if (pzRes == NULL) {
+#ifdef HAVE_DCGETTEXT
+ /*
+ * While processing the option_xlateable_txt data, try to use the
+ * "libopts" domain. Once we switch to the option descriptor data,
+ * do *not* use that domain.
+ */
+ if (option_xlateable_txt.field_ct != 0) {
+ res = dgettext("libopts", pz);
+ if (res == pz)
+ res = (char *)(void *)_(pz);
+ } else
+ res = (char *)(void *)_(pz);
+#else
+ res = (char *)(void *)_(pz);
+#endif
+ if (res == pz)
+ return res;
+ res = strdup(res);
+ if (res == NULL) {
fputs(_("No memory for duping translated strings\n"), stderr);
exit(SNTP_EXIT_FAILURE);
}
- return pzRes;
+ return res;
}
-static void coerce_it(void** s) { *s = AO_gettext(*s);
+/**
+ * All the pointers we use are marked "* const", but they are stored in
+ * writable memory. Coerce the mutability and set the pointer.
+ */
+static void coerce_it(void ** s) { *s = AO_gettext(*s);
}
/**
static void
translate_option_strings(void)
{
- tOptions * const pOpt = &sntpOptions;
+ tOptions * const opts = &sntpOptions;
/*
* Guard against re-translation. It won't work. The strings will have
* been changed by the first pass through this code. One shot only.
*/
- if (option_usage_text.field_ct != 0) {
+ if (option_xlateable_txt.field_ct != 0) {
/*
* Do the translations. The first pointer follows the field count
* field. The field count field is the size of a pointer.
*/
- tOptDesc * pOD = pOpt->pOptDesc;
- char ** ppz = (char**)(void*)&(option_usage_text);
- int ix = option_usage_text.field_ct;
+ tOptDesc * od = opts->pOptDesc;
+ char ** ppz = (char**)(void*)&(option_xlateable_txt);
+ int ix = option_xlateable_txt.field_ct;
do {
- ppz++;
+ ppz++; /* skip over field_ct */
*ppz = AO_gettext(*ppz);
} while (--ix > 0);
-
- coerce_it((void*)&(pOpt->pzCopyright));
- coerce_it((void*)&(pOpt->pzCopyNotice));
- coerce_it((void*)&(pOpt->pzFullVersion));
- coerce_it((void*)&(pOpt->pzUsageTitle));
- coerce_it((void*)&(pOpt->pzExplain));
- coerce_it((void*)&(pOpt->pzDetail));
- coerce_it((void*)&(pOpt->pzPackager));
- option_usage_text.field_ct = 0;
-
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++)
- coerce_it((void*)&(pOD->pzText));
+ /* prevent re-translation and disable "libopts" domain lookup */
+ option_xlateable_txt.field_ct = 0;
+
+ coerce_it((void*)&(opts->pzCopyright));
+ coerce_it((void*)&(opts->pzCopyNotice));
+ coerce_it((void*)&(opts->pzFullVersion));
+ coerce_it((void*)&(opts->pzUsageTitle));
+ coerce_it((void*)&(opts->pzExplain));
+ coerce_it((void*)&(opts->pzDetail));
+ coerce_it((void*)&(opts->pzPackager));
+
+ for (ix = opts->optCt; ix > 0; ix--, od++)
+ coerce_it((void*)&(od->pzText));
}
- if ((pOpt->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
- tOptDesc * pOD = pOpt->pOptDesc;
+ if ((opts->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
+ tOptDesc * od = opts->pOptDesc;
int ix;
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++) {
- coerce_it((void*)&(pOD->pz_Name));
- coerce_it((void*)&(pOD->pz_DisableName));
- coerce_it((void*)&(pOD->pz_DisablePfx));
+ for (ix = opts->optCt; ix > 0; ix--, od++) {
+ coerce_it((void*)&(od->pz_Name));
+ coerce_it((void*)&(od->pz_DisableName));
+ coerce_it((void*)&(od->pz_DisablePfx));
}
- /* prevent re-translation */
sntpOptions.fOptSet |= OPTPROC_NXLAT_OPT_CFG | OPTPROC_NXLAT_OPT;
}
}
/*
* EDIT THIS FILE WITH CAUTION (sntp-opts.h)
*
- * It has been AutoGen-ed January 1, 2013 at 11:25:28 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:02:55 PM by AutoGen 5.17.1pre11
* From the definitions sntp-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This header file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* tolerable version is at least as old as what was current when the header
* template was released.
*/
-#define AO_TEMPLATE_VERSION 147461
+#define AO_TEMPLATE_VERSION 151552
#if (AO_TEMPLATE_VERSION < OPTIONS_MINIMUM_VERSION) \
|| (AO_TEMPLATE_VERSION > OPTIONS_STRUCT_VERSION)
# error option template version mismatches autoopts/options.h header
} teOptIndex;
#define OPTION_CT 23
-#define SNTP_VERSION "4.2.7p343"
-#define SNTP_FULL_VERSION "sntp 4.2.7p343"
+#define SNTP_VERSION "4.2.7p344"
+#define SNTP_FULL_VERSION "sntp 4.2.7p344"
/*
* Interface defines for all options. Replace "n" with the UPPER_CASED
* Enumeration of sntp exit codes
*/
typedef enum {
- SNTP_EXIT_SUCCESS = 0,
- SNTP_EXIT_FAILURE = 1,
- SNTP_EXIT_NO_CONFIG_INPUT = 66,
- SNTP_EXIT_LIBOPTS_FAILURE = 70
+ SNTP_EXIT_SUCCESS = 0,
+ SNTP_EXIT_FAILURE = 1,
+ SNTP_EXIT_USAGE_ERROR = 64,
+ SNTP_EXIT_NO_CONFIG_INPUT = 66,
+ SNTP_EXIT_LIBOPTS_FAILURE = 70
} sntp_exit_code_t;
/*
* Make sure there are no #define name conflicts with the option names
#define SET_OPT_SAVE_OPTS(a) STMTS( \
DESC(SAVE_OPTS).fOptState &= OPTST_PERSISTENT_MASK; \
DESC(SAVE_OPTS).fOptState |= OPTST_SET; \
- DESC(SAVE_OPTS).optArg.argString = (char const*)(a) )
+ DESC(SAVE_OPTS).optArg.argString = (char const*)(a))
/*
* Interface defines not associated with particular options
*/
sntpOptions.pzCurOpt = NULL)
#define START_OPT RESTART_OPT(1)
#define USAGE(c) (*sntpOptions.pUsageProc)(&sntpOptions, c)
-/* extracted from opthead.tlib near line 484 */
+/* extracted from opthead.tlib near line 497 */
#ifdef __cplusplus
extern "C" {
-.TH sntp 1sntpman "02 Jan 2013" "4.2.7p343" "User Commands"
+.TH sntp 1sntpman "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (sntp-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:21:27 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:11:28 PM by AutoGen 5.17.1pre11
.\" From the definitions sntp-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B sntp
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..." [ hostname-or-IP ...]
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..." " " "[ hostname-or-IP ...]"
.PP
.SH DESCRIPTION
+.B
+can be used as an SNTP client to query a NTP or SNTP server and either display
+the time or set the local system's time (given suitable privilege). It can be
+run as an interactive command or from a
+.Ic cron
+job.
+NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol)
+are defined and described by RFC 5905.
+.PP
+The default is to write the estimated correct local date and time (i.e. not
+UTC) to the standard output in a format like:
+.Ic "'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'"
+where the
+.Ic "'(+0800)'"
+means that to get to UTC from the reported local time one must
+add 8 hours and 0 minutes,
+the
+.Ic "'+4.567'"
+indicates the local clock is 4.567 seconds behind the correct time
+(so 4.567 seconds must be added to the local clock to get it to be correct).
+Note that the number of decimals printed for this value will change
+based on the reported precision of the server.
+.Ic "'+/- 0.089'"
+is the reported
+.I synchronization distance
+(in seconds), which represents the maximum error due to all causes.
+If the server does not report valid data needed to calculate the
+synchronization distance, this will be reported as
+.Ic "'+/- ?'" .
+If the
+.I host
+is different from the
+.I IP ,
+both will be displayed.
+Otherwise, only the
+.I IP
+is displayed.
+Finally, the
+.I stratum
+of the host is reported.
.SH "OPTIONS"
.TP
.BR \-4 ", " -\-ipv4
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.SH USAGE
+.TP
+.BR Li "sntp ntpserver.somewhere"
+is the simplest use of this program
+and can be run as an unprivileged command
+to check the current time and error in the local clock.
+.TP
+.BR Li "sntp -a ntpserver.somewhere"
+With suitable privilege,
+run as a command
+or from a
+.Xr cron 8
+job,
+.Ic "sntp -a"
+will reset the local clock from a synchronized specified server,
+like the (deprecated)
+.Xr ntpdate 1ntpdatemdoc ,
+or
+.Xr rdate 8
+commands.
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH "FILES"
libopts had an internal operational error. Please report
it to autogen-users@lists.sourceforge.net. Thank you.
.SH AUTHORS
+.An "Johannes Maximilian Kuehn"
+.An "Harlan Stenn"
+.An "Dave Hart"
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of
+.B .
.PP
This manual page was \fIAutoGen\fP-erated from the \fBsntp\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt SNTP 1sntpmdoc User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (sntp-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:21:33 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:11:35 PM by AutoGen 5.17.1pre11
.\" From the definitions sntp-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
[ hostname-or-IP ...]
.Pp
.Sh DESCRIPTION
+.Nm
+can be used as an SNTP client to query a NTP or SNTP server and either display
+the time or set the local system's time (given suitable privilege). It can be
+run as an interactive command or from a
+.Ic cron
+job.
+NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol)
+are defined and described by RFC 5905.
+.Pp
+The default is to write the estimated correct local date and time (i.e. not
+UTC) to the standard output in a format like:
+.Ic "'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'"
+where the
+.Ic "'(+0800)'"
+means that to get to UTC from the reported local time one must
+add 8 hours and 0 minutes,
+the
+.Ic "'+4.567'"
+indicates the local clock is 4.567 seconds behind the correct time
+(so 4.567 seconds must be added to the local clock to get it to be correct).
+Note that the number of decimals printed for this value will change
+based on the reported precision of the server.
+.Ic "'+/- 0.089'"
+is the reported
+.Em synchronization distance
+(in seconds), which represents the maximum error due to all causes.
+If the server does not report valid data needed to calculate the
+synchronization distance, this will be reported as
+.Ic "'+/- ?'" .
+If the
+.Em host
+is different from the
+.Em IP ,
+both will be displayed.
+Otherwise, only the
+.Em IP
+is displayed.
+Finally, the
+.Em stratum
+of the host is reported.
.Sh "OPTIONS"
.Bl -tag
.It \-4 ", " -\-ipv4
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.Sh USAGE
+.Bl -tag -width indent
+.It Li "sntp ntpserver.somewhere"
+is the simplest use of this program
+and can be run as an unprivileged command
+to check the current time and error in the local clock.
+.It Li "sntp -a ntpserver.somewhere"
+With suitable privilege,
+run as a command
+or from a
+.Xr cron 8
+job,
+.Ic "sntp -a"
+will reset the local clock from a synchronized specified server,
+like the (deprecated)
+.Xr ntpdate 1ntpdatemdoc ,
+or
+.Xr rdate 8
+commands.
+.El
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh "FILES"
it to autogen-users@lists.sourceforge.net. Thank you.
.El
.Sh AUTHORS
+.An "Johannes Maximilian Kuehn"
+.An "Harlan Stenn"
+.An "Dave Hart"
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of
+.Nm .
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBsntp\fP
option definitions.
clock. Run as root, it can correct the system clock to this offset as
well. It can be run as an interactive command or from a cron job.
- <p>This document applies to version 4.2.7p343 of <code>sntp</code>.
+ <p>This document applies to version 4.2.7p344 of <code>sntp</code>.
<p>The program implements the SNTP protocol as defined by RFC 5905, the NTPv4
IETF specification.
can be used as an SNTP client to query a NTP or SNTP server and either display
the time or set the local system's time (given suitable privilege). It can be
run as an interactive command or from a
-<code>cron</code> job.
+<code>cron</code>
+job.
<p>NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol)
are defined and described by RFC 5905.
UTC) to the standard output in a format like:
<p><code>'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'</code>
-where the
-<code>'(+0800)'</code> means that to get to UTC from the reported local time one must
+
+ <p>where the
+<code>'(+0800)'</code>
+means that to get to UTC from the reported local time one must
add 8 hours and 0 minutes,
the
-<code>'+4.567'</code> indicates the local clock is 4.567 seconds behind the correct time
+<code>'+4.567'</code>
+indicates the local clock is 4.567 seconds behind the correct time
(so 4.567 seconds must be added to the local clock to get it to be correct).
Note that the number of decimals printed for this value will change
based on the reported precision of the server.
-<code>'+/- 0.089'</code> is the reported
-<em>synchronizationdistance</em>
+<code>'+/- 0.089'</code>
+is the reported
+<em> synchronization distance</em>
(in seconds), which represents the maximum error due to all causes.
If the server does not report valid data needed to calculate the
synchronization distance, this will be reported as
-<code>'+/- ?'</code>. If the
-<em>host</em>
+<code>'+/- ?'</code>.
+If the
+<em> host</em>
is different from the
-<em>IP</em>,
+<em> IP,</em>
both will be displayed.
Otherwise, only the
-<em>IP</em>
+<em> IP</em>
is displayed.
Finally, the
-<em>stratum</em>
+<em> stratum</em>
of the host is reported.
<p>This section was generated by <strong>AutoGen</strong>,
used to select the program, defaulting to <span class="file">more</span>. Both will exit
with a status code of 0.
-<pre class="example">sntp - standard Simple Network Time Protocol client program - Ver. 4.2.7p343
+<pre class="example">sntp - standard Simple Network Time Protocol client program - Ver. 4.2.7p344
USAGE: sntp [ -<flag> [<val>] | --<name>[{=| }<val>] ]... \
[ hostname-or-IP ...]
Flg Arg Option-Name Description
<h4 class="subsection">sntp Usage</h4>
<dl>
-<dt><span class="samp">Li</span><dd>is the simplest use of this program
+<dt><code>sntp ntpserver.somewhere</code><dd>is the simplest use of this program
and can be run as an unprivileged command
to check the current time and error in the local clock.
-<br><dt><span class="samp">Li</span><dd>With suitable privilege,
+<br><dt><code>sntp -a ntpserver.somewhere</code><dd>With suitable privilege,
run as a command
or from a
<code>cron(8)</code>
job,
-<code>sntp -a</code> will reset the local clock from a synchronized specified server,
+<code>sntp -a</code>
+will reset the local clock from a synchronized specified server,
like the (deprecated)
<code>ntpdate(1ntpdatemdoc)</code>,
or
<h4 class="subsection">sntp Authors</h4>
-<p>1<br>1<br>1<br>
+<p>Johannes Maximilian Kuehn<br>
+Harlan Stenn<br>
+Dave Hart<br>
<div class="node">
<p><hr>
<a name="sntp-Notes"></a>Previous: <a rel="previous" accesskey="p" href="#sntp-Authors">sntp Authors</a>,
-.TH sntp @SNTP_MS@ "02 Jan 2013" "4.2.7p343" "User Commands"
+.TH sntp @SNTP_MS@ "03 Jan 2013" "4.2.7p344" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (sntp-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:21:27 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:11:28 PM by AutoGen 5.17.1pre11
.\" From the definitions sntp-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B sntp
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..." [ hostname-or-IP ...]
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..." " " "[ hostname-or-IP ...]"
.PP
.SH DESCRIPTION
+.B
+can be used as an SNTP client to query a NTP or SNTP server and either display
+the time or set the local system's time (given suitable privilege). It can be
+run as an interactive command or from a
+.Ic cron
+job.
+NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol)
+are defined and described by RFC 5905.
+.PP
+The default is to write the estimated correct local date and time (i.e. not
+UTC) to the standard output in a format like:
+.Ic "'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'"
+where the
+.Ic "'(+0800)'"
+means that to get to UTC from the reported local time one must
+add 8 hours and 0 minutes,
+the
+.Ic "'+4.567'"
+indicates the local clock is 4.567 seconds behind the correct time
+(so 4.567 seconds must be added to the local clock to get it to be correct).
+Note that the number of decimals printed for this value will change
+based on the reported precision of the server.
+.Ic "'+/- 0.089'"
+is the reported
+.I synchronization distance
+(in seconds), which represents the maximum error due to all causes.
+If the server does not report valid data needed to calculate the
+synchronization distance, this will be reported as
+.Ic "'+/- ?'" .
+If the
+.I host
+is different from the
+.I IP ,
+both will be displayed.
+Otherwise, only the
+.I IP
+is displayed.
+Finally, the
+.I stratum
+of the host is reported.
.SH "OPTIONS"
.TP
.BR \-4 ", " -\-ipv4
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.SH USAGE
+.TP
+.BR Li "sntp ntpserver.somewhere"
+is the simplest use of this program
+and can be run as an unprivileged command
+to check the current time and error in the local clock.
+.TP
+.BR Li "sntp -a ntpserver.somewhere"
+With suitable privilege,
+run as a command
+or from a
+.Xr cron 8
+job,
+.Ic "sntp -a"
+will reset the local clock from a synchronized specified server,
+like the (deprecated)
+.Xr ntpdate @NTPDATE_MS@ ,
+or
+.Xr rdate 8
+commands.
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH "FILES"
libopts had an internal operational error. Please report
it to autogen-users@lists.sourceforge.net. Thank you.
.SH AUTHORS
+.An "Johannes Maximilian Kuehn"
+.An "Harlan Stenn"
+.An "Dave Hart"
.SH "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of
+.B .
.PP
This manual page was \fIAutoGen\fP-erated from the \fBsntp\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt SNTP @SNTP_MS@ User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (sntp-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:21:33 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:11:35 PM by AutoGen 5.17.1pre11
.\" From the definitions sntp-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
[ hostname-or-IP ...]
.Pp
.Sh DESCRIPTION
+.Nm
+can be used as an SNTP client to query a NTP or SNTP server and either display
+the time or set the local system's time (given suitable privilege). It can be
+run as an interactive command or from a
+.Ic cron
+job.
+NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol)
+are defined and described by RFC 5905.
+.Pp
+The default is to write the estimated correct local date and time (i.e. not
+UTC) to the standard output in a format like:
+.Ic "'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'"
+where the
+.Ic "'(+0800)'"
+means that to get to UTC from the reported local time one must
+add 8 hours and 0 minutes,
+the
+.Ic "'+4.567'"
+indicates the local clock is 4.567 seconds behind the correct time
+(so 4.567 seconds must be added to the local clock to get it to be correct).
+Note that the number of decimals printed for this value will change
+based on the reported precision of the server.
+.Ic "'+/- 0.089'"
+is the reported
+.Em synchronization distance
+(in seconds), which represents the maximum error due to all causes.
+If the server does not report valid data needed to calculate the
+synchronization distance, this will be reported as
+.Ic "'+/- ?'" .
+If the
+.Em host
+is different from the
+.Em IP ,
+both will be displayed.
+Otherwise, only the
+.Em IP
+is displayed.
+Finally, the
+.Em stratum
+of the host is reported.
.Sh "OPTIONS"
.Bl -tag
.It \-4 ", " -\-ipv4
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.Sh USAGE
+.Bl -tag -width indent
+.It Li "sntp ntpserver.somewhere"
+is the simplest use of this program
+and can be run as an unprivileged command
+to check the current time and error in the local clock.
+.It Li "sntp -a ntpserver.somewhere"
+With suitable privilege,
+run as a command
+or from a
+.Xr cron 8
+job,
+.Ic "sntp -a"
+will reset the local clock from a synchronized specified server,
+like the (deprecated)
+.Xr ntpdate @NTPDATE_MS@ ,
+or
+.Xr rdate 8
+commands.
+.El
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh "FILES"
it to autogen-users@lists.sourceforge.net. Thank you.
.El
.Sh AUTHORS
+.An "Johannes Maximilian Kuehn"
+.An "Harlan Stenn"
+.An "Dave Hart"
.Sh "COPYRIGHT"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh "BUGS"
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of
+.Nm .
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBsntp\fP
option definitions.
#
# EDIT THIS FILE WITH CAUTION (invoke-ntp-keygen.texi)
#
-# It has been AutoGen-ed January 2, 2013 at 02:21:09 AM by AutoGen 5.16.2
+# It has been AutoGen-ed January 3, 2013 at 01:11:09 PM by AutoGen 5.17.1pre11
# From the definitions ntp-keygen-opts.def
# and the template file agtexi-cmd.tpl
@end ignore
Some files used by this program are encrypted using a private password.
The
-@code{-p} option specifies the password for local encrypted files and the
-@code{-q} option the password for encrypted files sent to remote sites.
+@code{-p}
+option specifies the password for local encrypted files and the
+@code{-q}
+option the password for encrypted files sent to remote sites.
If no password is specified, the host name returned by the Unix
@code{gethostname}()
function, normally the DNS name of the host is used.
The
-@code{pw} option of the
-@code{crypto} configuration command specifies the read
+@kbd{pw}
+option of the
+@kbd{crypto}
+configuration command specifies the read
password for previously encrypted local files.
This must match the local password used by this program.
If not specified, the host name is used.
Thus, if files are generated by this program without password,
they can be read back by
-@code{ntpd} without password but only on the same host.
+@kbd{ntpd}
+without password but only on the same host.
Normally, encrypted files for each host are generated by that host and
used only by that host, although exceptions exist as noted later on
this page.
The symmetric keys file, normally called
-@code{ntp.keys}, is usually installed in
+@kbd{ntp.keys},
+is usually installed in
@file{/etc}.
Other files and links are usually installed in
@file{/usr/local/etc},
which is normally in a shared filesystem in
NFS-mounted networks and cannot be changed by shared clients.
The location of the keys directory can be changed by the
-@code{keysdir} configuration command in such cases.
+@kbd{keysdir}
+configuration command in such cases.
Normally, this is in
@file{/etc}.
This program directs commentary and error messages to the standard
error stream
-@code{stderr} and remote files to the standard output stream
-@code{stdout} where they can be piped to other applications or redirected to files.
+@kbd{stderr}
+and remote files to the standard output stream
+@kbd{stdout}
+where they can be piped to other applications or redirected to files.
The names used for generated files and links all begin with the
string
-@code{ntpkey} and include the file type, generating host and filestamp,
+@kbd{ntpkey}
+and include the file type, generating host and filestamp,
as described in the
@quotedblleft{}Cryptographic Data Files@quotedblright{}
section below.
-@node Running
-@section Running
+@node Running the Program
+@section Running the Program
+
-Running
-the
-Program
To test and gain experience with Autokey concepts, log in as root and
change to the keys directory, usually
@file{/usr/local/etc}
When run for the first time, or if all files with names beginning with
-@code{ntpkey} have been removed, use the
+@kbd{ntpkey}
+have been removed, use the
@code{ntp-keygen}
command without arguments to generate a
default RSA host key and matching RSA-MD5 certificate with expiration
Designate one of them as the trusted host (TH) using
@code{ntp-keygen}
with the
-@code{-T} option and configure it to synchronize from reliable Internet servers.
+@code{-T}
+option and configure it to synchronize from reliable Internet servers.
Then configure the other hosts to synchronize to the TH directly or
indirectly.
A certificate trail is created when Autokey asks the immediately
By default, the host key is also the sign key used to encrypt
signatures.
A different sign key can be assigned using the
-@code{-S} option and this can be either RSA or DSA type.
+@code{-S}
+option and this can be either RSA or DSA type.
By default, the signature
message digest type is MD5, but any combination of sign key type and
message digest type supported by the OpenSSL library can be specified
using the
-@code{-c} option.
+@code{-c}
+option.
The rules say cryptographic media should be generated with proventic
filestamps, which means the host should already be synchronized before
this program is run.
The
@code{ntpd(1ntpdmdoc)}
configuration command
-@code{crypto} @code{pw} @code{password} specifies the read password for previously encrypted files.
+@code{crypto} @code{pw} @kbd{password}
+specifies the read password for previously encrypted files.
The daemon expires on the spot if the password is missing
or incorrect.
For convenience, if a file has been previously encrypted,
File names begin with the prefix
-@code{ntpkey_} and end with the postfix
-@code{_hostname.filestamp}, where
-@code{hostname} is the owner name, usually the string returned
+@code{ntpkey_}
+and end with the postfix
+@kbd{_hostname.filestamp},
+where
+@kbd{hostname}
+is the owner name, usually the string returned
by the Unix gethostname() routine, and
-@code{filestamp} is the NTP seconds when the file was generated, in decimal digits.
+@kbd{filestamp}
+is the NTP seconds when the file was generated, in decimal digits.
This both guarantees uniqueness and simplifies maintenance
procedures, since all files can be quickly removed
by a
-@code{rm} @code{ntpkey\&*} command or all files generated
+@code{rm} @code{ntpkey*}
+command or all files generated
at a specific time can be removed by a
-@code{rm} @code{\&*filestamp} command.
+@code{rm}
+@kbd{*filestamp}
+command.
To further reduce the risk of misconfiguration,
the first two lines of a file contain the file name
and generation date and time as comments.
program uses the same timestamp extension for all files generated
at one time, so each generation is distinct and can be readily
recognized in monitoring data.
-@node Running
-@section Running
+@node Running the program
+@section Running the program
+
-Running
-the
-program
The safest way to run the
@code{ntp-keygen}
program is logged in directly as root.
then run the program.
When run for the first time,
or if all
-@code{ntpkey} files have been removed,
+@code{ntpkey}
+files have been removed,
the program generates a RSA host key file and matching RSA-MD5 certificate file,
which is all that is necessary in many cases.
The program also generates soft links from the generic names
as the other files, are probably not compatible with anything other than Autokey.
Running the program as other than root and using the Unix
-@code{su} command
+@code{su}
+command
to assume root may not work properly, since by default the OpenSSL library
looks for the random seed file
-@code{.rnd} in the user home directory.
+@code{.rnd}
+in the user home directory.
However, there should be only one
-@code{.rnd}, most conveniently
+@code{.rnd},
+most conveniently
in the root directory, so it is convenient to define the
-@code{$RANDFILE} environment variable used by the OpenSSL library as the path to
-@code{/.rnd}.
+@code{$RANDFILE}
+environment variable used by the OpenSSL library as the path to
+@code{/.rnd}.
+
Installing the keys as root might not work in NFS-mounted
shared file systems, as NFS clients may not be able to write
to the shared keys directory, even as root.
directory such as
@file{/etc}
using the
-@code{keysdir} command.
+@code{keysdir}
+command.
There is no need for one client to read the keys and certificates
of other clients or servers, as these data are obtained automatically
by the Autokey protocol.
program uses the same timestamp extension for all files generated
at one time, so each generation is distinct and can be readily
recognized in monitoring data.
-@node Running
-@section Running
+@node Running the program
+@section Running the program
+
-Running
-the
-program
The safest way to run the
@code{ntp-keygen}
program is logged in directly as root.
then run the program.
When run for the first time,
or if all
-@code{ntpkey} files have been removed,
+@code{ntpkey}
+files have been removed,
the program generates a RSA host key file and matching RSA-MD5 certificate file,
which is all that is necessary in many cases.
The program also generates soft links from the generic names
as the other files, are probably not compatible with anything other than Autokey.
Running the program as other than root and using the Unix
-@code{su} command
+@code{su}
+command
to assume root may not work properly, since by default the OpenSSL library
looks for the random seed file
-@code{.rnd} in the user home directory.
+@code{.rnd}
+in the user home directory.
However, there should be only one
-@code{.rnd}, most conveniently
+@code{.rnd},
+most conveniently
in the root directory, so it is convenient to define the
-@code{$RANDFILE} environment variable used by the OpenSSL library as the path to
-@code{/.rnd}.
+@code{$RANDFILE}
+environment variable used by the OpenSSL library as the path to
+@code{/.rnd}.
+
Installing the keys as root might not work in NFS-mounted
shared file systems, as NFS clients may not be able to write
to the shared keys directory, even as root.
directory such as
@file{/etc}
using the
-@code{keysdir} command.
+@code{keysdir}
+command.
There is no need for one client to read the keys and certificates
of other clients or servers, as these data are obtained automatically
by the Autokey protocol.
Each cryptographic configuration involves selection of a signature scheme
and identification scheme, called a cryptotype,
as explained in the
-@ref{Authentication}Authentication
-Options
+@ref{Authentication Options}
section of
@code{ntp.conf(5)}.
The default cryptotype uses RSA encryption, MD5 message digest
a certificate trail ending at a trusted host.
The trail is defined by static configuration file entries
or dynamic means described on the
-@ref{Automatic}Automatic
-NTP
-Configuration
-Options
+@ref{Automatic NTP Configuration Options}
section of
@code{ntp.conf(5)}.
On each trusted host as root, change to the keys directory.
To insure a fresh fileset, remove all
-@code{ntpkey} files.
+@code{ntpkey}
+files.
Then run
@code{ntp-keygen}
-@code{-T} to generate keys and a trusted certificate.
+@code{-T}
+to generate keys and a trusted certificate.
On all other hosts do the same, but leave off the
-@code{-T} flag to generate keys and nontrusted certificates.
+@code{-T}
+flag to generate keys and nontrusted certificates.
When complete, start the NTP daemons beginning at the lowest stratum
and working up the tree.
It may take some time for Autokey to instantiate the certificate trails
scheme than the default, run
@code{ntp-keygen}
with the
-@code{-S} @code{-type} option, where
-@code{type} is either
-@code{RSA} or
-@code{DSA}. The most often need to do this is when a DSA-signed certificate is used.
+@code{-S} @kbd{-type}
+option, where
+@kbd{type}
+is either
+@code{RSA}
+or
+@code{DSA}.
+The most often need to do this is when a DSA-signed certificate is used.
If it is necessary to use a different certificate scheme than the default,
run
@code{ntp-keygen}
with the
-@code{-c} @code{-scheme} option and selected
-@code{scheme} as needed.
+@code{-c} @kbd{-scheme}
+option and selected
+@kbd{scheme}
+as needed.
f
@code{ntp-keygen}
is run again without these options, it generates a new certificate
is restarted, it loads any new files and restarts the protocol.
Other dependent hosts will continue as usual until signatures are refreshed,
at which time the protocol is restarted.
-@node Identity
-@section Identity
+@node Identity Schemes
+@section Identity Schemes
+
-Identity
-Schemes
As mentioned on the Autonomous Authentication page,
the default TC identity scheme is vulnerable to a middleman attack.
However, there are more secure identity schemes available,
"Identification Schemes"
page
(maybe available at
-.Li
-http://www.eecis.udel.edu/%7emills/keygen.html
-)
-.
+@code{http://www.eecis.udel.edu/%7emills/keygen.html}).
These schemes are based on a TA, one or more trusted hosts
and some number of nontrusted hosts.
Trusted hosts prove identity using values provided by the TA,
The PC scheme supports only one trusted host in the group.
On trusted host alice run
@code{ntp-keygen}
-@code{-P} @code{-p} @code{-password} to generate the host key file
-@file{ntpkey_RSAkey_}NsAralice.filestamp
+@code{-P}
+@code{-p} @kbd{-password}
+to generate the host key file
+@file{ntpkey_RSAkey_}@kbd{alice.filestamp}
and trusted private certificate file
-@file{ntpkey_RSA-MD5_cert_}NsAralice.filestamp.
+@file{ntpkey_RSA-MD5_cert_}@kbd{alice.filestamp}.
Copy both files to all group hosts;
they replace the files which would be generated in other schemes.
On each host bob install a soft link from the generic name
-@file{ntpkey_host_}NsArbob
+@file{ntpkey_host_}@kbd{bob}
to the host key file and soft link
-@file{ntpkey_cert_}NsArbob
+@file{ntpkey_cert_}@kbd{bob}
to the private certificate file.
Note the generic links are on bob, but point to files generated
by trusted host alice.
generate the IFF parameter file.
On trusted host alice run
@code{ntp-keygen}
-@code{-T} @code{-I} @code{-p} @code{-password} to produce her parameter file
-@file{ntpkey_IFFpar_}NsAralice.filestamp,
+@code{-T}
+@code{-I}
+@code{-p} @kbd{-password}
+to produce her parameter file
+@file{ntpkey_IFFpar_}@kbd{alice.filestamp},
which includes both server and client keys.
Copy this file to all group hosts that operate as both servers
and clients and install a soft link from the generic
-@file{ntpkey_iff_}NsAralice
+@file{ntpkey_iff_}@kbd{alice}
to this file.
If there are no hosts restricted to operate only as clients,
there is nothing further to do.
from the parameter file and distributed to all restricted clients.
After generating the parameter file, on alice run
@code{ntp-keygen}
-@code{-e} and pipe the output to a file or mail program.
+@code{-e}
+and pipe the output to a file or mail program.
Copy or mail this file to all restricted clients.
On these clients install a soft link from the generic
-@file{ntpkey_iff_}NsAralice
+@file{ntpkey_iff_}@kbd{alice}
to this file.
To further protect the integrity of the keys,
each file can be encrypted with a secret password.
in the group, generate the IFF parameter file.
On trusted host alice run
@code{ntp-keygen}
-@code{-T} @code{-G} @code{-p} @code{-password} to produce her parameter file
-@file{ntpkey_GQpar_}NsAralice.filestamp,
+@code{-T}
+@code{-G}
+@code{-p} @kbd{-password}
+to produce her parameter file
+@file{ntpkey_GQpar_}@kbd{alice.filestamp},
which includes both server and client keys.
Copy this file to all group hosts and install a soft link
from the generic
-@file{ntpkey_gq_}NsAralice
+@file{ntpkey_gq_}@kbd{alice}
to this file.
In addition, on each host bob install a soft link
from generic
-@file{ntpkey_gq_}NsArbob
+@file{ntpkey_gq_}@kbd{bob}
to this file.
As the GQ scheme updates the GQ parameters file and certificate
at the same time, keys and certificates can be regenerated as needed.
and bob one of her clients.
On TA trish run
@code{ntp-keygen}
-@code{-V} @code{-n} @code{-p} @code{-password}, where
-@code{n} is the number of revokable keys (typically 5) to produce
+@code{-V} @kbd{-n}
+@code{-p} @kbd{-password},
+where
+@kbd{n}
+is the number of revokable keys (typically 5) to produce
the parameter file
-@file{ntpkeys_MVpar_}NsArtrish.filestamp
+@file{ntpkeys_MVpar_}@kbd{trish.filestamp}
and client key files
-@file{ntpkeys_MVkeyd_}NsArtrish.filestamp
+@file{ntpkeys_MVkeyd_}@kbd{trish.filestamp}
where
-@code{d} is the key number (0 \&<
-@code{d} \&<
-@code{n}). Copy the parameter file to alice and install a soft link
+@kbd{d}
+is the key number (0 \&<
+@kbd{d}
+\&<
+@kbd{n}).
+Copy the parameter file to alice and install a soft link
from the generic
-@file{ntpkey_mv_}NsAralice
+@file{ntpkey_mv_}@kbd{alice}
to this file.
Copy one of the client key files to alice for later distribution
to her clients.
since they all work the same way.
Alice copies the client key file to all of her cliens.
On client bob install a soft link from generic
-@file{ntpkey_mvkey_}NsArbob
+@file{ntpkey_mvkey_}@kbd{bob}
to the client key file.
As the MV scheme is independent of keys and certificates,
these files can be refreshed as needed.
-@node Command
-@section Command
+@node Command Line Options
+@section Command Line Options
-Command
-Line
-Options
-@table @samp
-@item Fl
+
+@table @asis
+
+@item @code{-c} @kbd{-scheme}
Select certificate message digest/signature encryption scheme.
The
-@code{scheme} can be one of the following:
-.
-Cm
-RSA-MD2
-,
-RSA-MD5
-,
-RSA-SHA
-,
-RSA-SHA1
-,
-RSA-MDC2
-,
-RSA-RIPEMD160
-,
-DSA-SHA
-,
+@kbd{scheme}
+can be one of the following:
+
or
-@code{DSA-SHA1}. Note that RSA schemes must be used with a RSA sign key and DSA
+@code{DSA-SHA1}.
+Note that RSA schemes must be used with a RSA sign key and DSA
schemes must be used with a DSA sign key.
The default without this option is
-@code{RSA-MD5}. @item Fl
+@code{RSA-MD5}.
+@item @code{-d}
Enable debugging.
This option displays the cryptographic data produced in eye-friendly billboards.
-@item Fl
+@item @code{-e}
Write the IFF client keys to the standard output.
This is intended for automatic key distribution by mail.
-@item Fl
+@item @code{-G}
Generate parameters and keys for the GQ identification scheme,
obsoleting any that may exist.
-@item Fl
+@item @code{-g}
Generate keys for the GQ identification scheme
using the existing GQ parameters.
If the GQ parameters do not yet exist, create them first.
-@item Fl
+@item @code{-H}
Generate new host keys, obsoleting any that may exist.
-@item Fl
+@item @code{-I}
Generate parameters for the IFF identification scheme,
obsoleting any that may exist.
-@item Fl
+@item @code{-i} @kbd{-name}
Set the suject name to
-@code{name}. This is used as the subject field in certificates
+@kbd{name}.
+This is used as the subject field in certificates
and in the file name for host and sign keys.
-@item Fl
+@item @code{-M}
Generate MD5 keys, obsoleting any that may exist.
-@item Fl
+@item @code{-P}
Generate a private certificate.
By default, the program generates public certificates.
-@item Fl
+@item @code{-p} @kbd{-password}
Encrypt generated files containing private data with
-@code{password} and the DES-CBC algorithm.
-@item Fl
+@kbd{password}
+and the DES-CBC algorithm.
+@item @code{-q}
Set the password for reading files to password.
-@item Fl
+@item @code{-S} @code{-Oo} @code{-Cm} @code{-RSA} @code{-} | @code{-DSA} @code{-Oc}
Generate a new sign key of the designated type,
obsoleting any that may exist.
By default, the program uses the host key as the sign key.
-@item Fl
+@item @code{-s} @kbd{-name}
Set the issuer name to
-@code{name}. This is used for the issuer field in certificates
+@kbd{name}.
+This is used for the issuer field in certificates
and in the file name for identity files.
-@item Fl
+@item @code{-T}
Generate a trusted certificate.
By default, the program generates a non-trusted certificate.
-@item Fl
+@item @code{-V} @kbd{-nkeys}
Generate parameters and keys for the Mu-Varadharajan (MV) identification scheme.
@end table
-@node Random
-@section Random
+@node Random Seed File
+@section Random Seed File
+
-Random
-Seed
-File
All cryptographically sound key generation schemes must have means
to randomize the entropy seed used to initialize
the internal pseudo-random number generator used
The entropy seed used by the OpenSSL library is contained in a file,
usually called
-@code{.rnd}, which must be available when starting the NTP daemon
+@code{.rnd},
+which must be available when starting the NTP daemon
or the
@code{ntp-keygen}
program.
The NTP daemon will first look for the file
using the path specified by the
-@code{randfile} subcommand of the
-@code{crypto} configuration command.
+@code{randfile}
+subcommand of the
+@code{crypto}
+configuration command.
If not specified in this way, or when starting the
@code{ntp-keygen}
program,
the OpenSSL library will look for the file using the path specified
by the
-.Ev
-RANDFILE
+Ev RANDFILE
environment variable in the user home directory,
whether root or some other user.
If the
-.Ev
-RANDFILE
+Ev RANDFILE
environment variable is not present,
the library will look for the
-@code{.rnd} file in the user home directory.
+@code{.rnd}
+file in the user home directory.
If the file is not available or cannot be written,
the daemon exits with a message to the system log and the program
exits with a suitable error message.
-@node Cryptographic
-@section Cryptographic
+@node Cryptographic Data Files
+@section Cryptographic Data Files
+
-Cryptographic
-Data
-Files
All other file formats begin with two lines.
The first contains the file name, including the generated host name
and filestamp.
is MD5 alphanumeric strings.
Following hte heard the keys are
entered one per line in the format
-.D1
-Ar
-keyno
-type
-key
+@example
+@kbd{keyno} @kbd{type} @kbd{key}
+@end example
where
-@code{keyno} is a positive integer in the range 1-65,535,
-@code{type} is the string MD5 defining the key format and
-@code{key} is the key itself,
+@kbd{keyno}
+is a positive integer in the range 1-65,535,
+@kbd{type}
+is the string MD5 defining the key format and
+@kbd{key}
+is the key itself,
which is a printable ASCII string 16 characters or less in length.
Each character is chosen from the 93 printable characters
in the range 0x21 through 0x7f excluding space and the
-@quoteleft{}@quoteright{}#
+@quoteleft{}#@quoteright{}
character.
Note that the keys used by the
The
@code{ntp-keygen}
program generates a MD5 symmetric keys file
-@file{ntpkey_MD5key_}NsArhostname.filestamp.
+@file{ntpkey_MD5key_}@kbd{hostname.filestamp}.
Since the file contains private shared keys,
it should be visible only to root and distributed by secure means
to other subnet hosts.
@exampleindent 0
@example
-ntp-keygen (ntp) - Create a NTP host key - Ver. 4.2.7p343
+ntp-keygen (ntp) - Create a NTP host key - Ver. 4.2.7p344
USAGE: ntp-keygen [ -<flag> [<val>] | --<name>[@{=| @}<val>] ]...
Flg Arg Option-Name Description
-b Num imbits identity modulus bits
@node ntp-keygen Usage
@subsection ntp-keygen Usage
The
-@code{-p} @code{-password} option specifies the write password and
-@code{-q} @code{-password} option the read password for previously encrypted files.
+@code{-p} @kbd{-password}
+option specifies the write password and
+@code{-q} @kbd{-password}
+option the read password for previously encrypted files.
The
@code{ntp-keygen}
program prompts for the password if it reads an encrypted file
/*
* EDIT THIS FILE WITH CAUTION (ntp-keygen-opts.c)
*
- * It has been AutoGen-ed January 2, 2013 at 02:20:55 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:10:51 PM by AutoGen 5.17.1pre11
* From the definitions ntp-keygen-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This source file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* ntp-keygen option static const strings
*/
static char const ntp_keygen_opt_strs[2358] =
-/* 0 */ "ntp-keygen (ntp) 4.2.7p343\n"
+/* 0 */ "ntp-keygen (ntp) 4.2.7p344\n"
"Copyright (C) 1970-2013 The University of Delaware, all rights reserved.\n"
"This is free software. It is licensed for use, modification and\n"
"redistribution under the terms of the NTP License, copies of which\n"
/* 2136 */ "no-load-opts\0"
/* 2149 */ "no\0"
/* 2152 */ "NTP_KEYGEN\0"
-/* 2163 */ "ntp-keygen (ntp) - Create a NTP host key - Ver. 4.2.7p343\n"
+/* 2163 */ "ntp-keygen (ntp) - Create a NTP host key - Ver. 4.2.7p344\n"
"USAGE: %s [ -<flag> [<val>] | --<name>[{=| }<val>] ]...\n\0"
/* 2279 */ "$HOME\0"
/* 2285 */ ".\0"
/* 2287 */ ".ntprc\0"
/* 2294 */ "http://bugs.ntp.org, bugs@ntp.org\0"
/* 2328 */ "\n\n\0"
-/* 2331 */ "ntp-keygen (ntp) 4.2.7p343";
+/* 2331 */ "ntp-keygen (ntp) 4.2.7p344";
/*
* imbits option description:
#define zExplain (ntp_keygen_opt_strs+2328)
#define zDetail (NULL)
#define zFullVersion (ntp_keygen_opt_strs+2331)
-/* extracted from optcode.tlib near line 350 */
+/* extracted from optcode.tlib near line 353 */
#if defined(ENABLE_NLS)
# define OPTPROC_BASE OPTPROC_TRANSLATE
option_usage_fp = stderr;
-emit_ranges:
+ emit_ranges:
optionShowRange(pOptions, pOptDesc, (void *)rng, 1);
}
#endif /* defined AUTOKEY */
static void
doOptDebug_Level(tOptions* pOptions, tOptDesc* pOptDesc)
{
+ /*
+ * Be sure the flag-code[0] handles special values for the options pointer
+ * viz. (poptions <= OPTPROC_EMIT_LIMIT) *and also* the special flag bit
+ * ((poptdesc->fOptState & OPTST_RESET) != 0) telling the option to
+ * reset its state.
+ */
/* extracted from debug-opt.def, line 15 */
OPT_VALUE_SET_DEBUG_LEVEL++;
(void)pOptDesc;
option_usage_fp = stderr;
-emit_ranges:
+ emit_ranges:
optionShowRange(pOptions, pOptDesc, (void *)rng, 1);
}
#endif /* defined AUTOKEY */
-/* extracted from optmain.tlib near line 48 */
+/* extracted from optmain.tlib near line 46 */
#if defined(TEST_NTP_KEYGEN_OPTS) /* TEST MAIN PROCEDURE: */
return res;
}
#endif /* defined TEST_NTP_KEYGEN_OPTS */
-/* extracted from optmain.tlib near line 1146 */
+/* extracted from optmain.tlib near line 1188 */
/**
* The directory containing the data associated with ntp-keygen.
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#ifdef HAVE_DCGETTEXT
+# include <gettext.h>
+#endif
#include <autoopts/usage-txt.h>
-static char* AO_gettext(char const* pz);
-static void coerce_it(void** s);
+static char * AO_gettext(char const * pz);
+static void coerce_it(void ** s);
/**
- * AutoGen specific wrapper function for gettext.
- * It relies on the macro _() to convert from English to the target
- * language, then strdup-duplicates the result string.
+ * AutoGen specific wrapper function for gettext. It relies on the macro _()
+ * to convert from English to the target language, then strdup-duplicates the
+ * result string. It tries the "libopts" domain first, then whatever has been
+ * set via the \a textdomain(3) call.
*
* @param[in] pz the input text used as a lookup key.
* @returns the translated text (if there is one),
* or the original text (if not).
*/
static char *
-AO_gettext(char const* pz)
+AO_gettext(char const * pz)
{
- char* pzRes;
+ char * res;
if (pz == NULL)
return NULL;
- pzRes = _(pz);
- if (pzRes == pz)
- return pzRes;
- pzRes = strdup(pzRes);
- if (pzRes == NULL) {
+#ifdef HAVE_DCGETTEXT
+ /*
+ * While processing the option_xlateable_txt data, try to use the
+ * "libopts" domain. Once we switch to the option descriptor data,
+ * do *not* use that domain.
+ */
+ if (option_xlateable_txt.field_ct != 0) {
+ res = dgettext("libopts", pz);
+ if (res == pz)
+ res = (char *)(void *)_(pz);
+ } else
+ res = (char *)(void *)_(pz);
+#else
+ res = (char *)(void *)_(pz);
+#endif
+ if (res == pz)
+ return res;
+ res = strdup(res);
+ if (res == NULL) {
fputs(_("No memory for duping translated strings\n"), stderr);
exit(NTP_KEYGEN_EXIT_FAILURE);
}
- return pzRes;
+ return res;
}
-static void coerce_it(void** s) { *s = AO_gettext(*s);
+/**
+ * All the pointers we use are marked "* const", but they are stored in
+ * writable memory. Coerce the mutability and set the pointer.
+ */
+static void coerce_it(void ** s) { *s = AO_gettext(*s);
}
/**
static void
translate_option_strings(void)
{
- tOptions * const pOpt = &ntp_keygenOptions;
+ tOptions * const opts = &ntp_keygenOptions;
/*
* Guard against re-translation. It won't work. The strings will have
* been changed by the first pass through this code. One shot only.
*/
- if (option_usage_text.field_ct != 0) {
+ if (option_xlateable_txt.field_ct != 0) {
/*
* Do the translations. The first pointer follows the field count
* field. The field count field is the size of a pointer.
*/
- tOptDesc * pOD = pOpt->pOptDesc;
- char ** ppz = (char**)(void*)&(option_usage_text);
- int ix = option_usage_text.field_ct;
+ tOptDesc * od = opts->pOptDesc;
+ char ** ppz = (char**)(void*)&(option_xlateable_txt);
+ int ix = option_xlateable_txt.field_ct;
do {
- ppz++;
+ ppz++; /* skip over field_ct */
*ppz = AO_gettext(*ppz);
} while (--ix > 0);
-
- coerce_it((void*)&(pOpt->pzCopyright));
- coerce_it((void*)&(pOpt->pzCopyNotice));
- coerce_it((void*)&(pOpt->pzFullVersion));
- coerce_it((void*)&(pOpt->pzUsageTitle));
- coerce_it((void*)&(pOpt->pzExplain));
- coerce_it((void*)&(pOpt->pzDetail));
- coerce_it((void*)&(pOpt->pzPackager));
- option_usage_text.field_ct = 0;
-
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++)
- coerce_it((void*)&(pOD->pzText));
+ /* prevent re-translation and disable "libopts" domain lookup */
+ option_xlateable_txt.field_ct = 0;
+
+ coerce_it((void*)&(opts->pzCopyright));
+ coerce_it((void*)&(opts->pzCopyNotice));
+ coerce_it((void*)&(opts->pzFullVersion));
+ coerce_it((void*)&(opts->pzUsageTitle));
+ coerce_it((void*)&(opts->pzExplain));
+ coerce_it((void*)&(opts->pzDetail));
+ coerce_it((void*)&(opts->pzPackager));
+
+ for (ix = opts->optCt; ix > 0; ix--, od++)
+ coerce_it((void*)&(od->pzText));
}
- if ((pOpt->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
- tOptDesc * pOD = pOpt->pOptDesc;
+ if ((opts->fOptSet & OPTPROC_NXLAT_OPT_CFG) == 0) {
+ tOptDesc * od = opts->pOptDesc;
int ix;
- for (ix = pOpt->optCt; ix > 0; ix--, pOD++) {
- coerce_it((void*)&(pOD->pz_Name));
- coerce_it((void*)&(pOD->pz_DisableName));
- coerce_it((void*)&(pOD->pz_DisablePfx));
+ for (ix = opts->optCt; ix > 0; ix--, od++) {
+ coerce_it((void*)&(od->pz_Name));
+ coerce_it((void*)&(od->pz_DisableName));
+ coerce_it((void*)&(od->pz_DisablePfx));
}
- /* prevent re-translation */
ntp_keygenOptions.fOptSet |= OPTPROC_NXLAT_OPT_CFG | OPTPROC_NXLAT_OPT;
}
}
/*
* EDIT THIS FILE WITH CAUTION (ntp-keygen-opts.h)
*
- * It has been AutoGen-ed January 2, 2013 at 02:20:55 AM by AutoGen 5.16.2
+ * It has been AutoGen-ed January 3, 2013 at 01:10:51 PM by AutoGen 5.17.1pre11
* From the definitions ntp-keygen-opts.def
* and the template file options
*
- * Generated from AutoOpts 36:5:11 templates.
+ * Generated from AutoOpts 37:0:12 templates.
*
* AutoOpts is a copyrighted work. This header file is not encumbered
* by AutoOpts licensing, but is provided under the licensing terms chosen
* tolerable version is at least as old as what was current when the header
* template was released.
*/
-#define AO_TEMPLATE_VERSION 147461
+#define AO_TEMPLATE_VERSION 151552
#if (AO_TEMPLATE_VERSION < OPTIONS_MINIMUM_VERSION) \
|| (AO_TEMPLATE_VERSION > OPTIONS_STRUCT_VERSION)
# error option template version mismatches autoopts/options.h header
} teOptIndex;
#define OPTION_CT 26
-#define NTP_KEYGEN_VERSION "4.2.7p343"
-#define NTP_KEYGEN_FULL_VERSION "ntp-keygen (ntp) 4.2.7p343"
+#define NTP_KEYGEN_VERSION "4.2.7p344"
+#define NTP_KEYGEN_FULL_VERSION "ntp-keygen (ntp) 4.2.7p344"
/*
* Interface defines for all options. Replace "n" with the UPPER_CASED
* Enumeration of ntp-keygen exit codes
*/
typedef enum {
- NTP_KEYGEN_EXIT_SUCCESS = 0,
- NTP_KEYGEN_EXIT_FAILURE = 1,
+ NTP_KEYGEN_EXIT_SUCCESS = 0,
+ NTP_KEYGEN_EXIT_FAILURE = 1,
+ NTP_KEYGEN_EXIT_USAGE_ERROR = 64,
NTP_KEYGEN_EXIT_NO_CONFIG_INPUT = 66,
NTP_KEYGEN_EXIT_LIBOPTS_FAILURE = 70
} ntp_keygen_exit_code_t;
#define SET_OPT_SAVE_OPTS(a) STMTS( \
DESC(SAVE_OPTS).fOptState &= OPTST_PERSISTENT_MASK; \
DESC(SAVE_OPTS).fOptState |= OPTST_SET; \
- DESC(SAVE_OPTS).optArg.argString = (char const*)(a) )
+ DESC(SAVE_OPTS).optArg.argString = (char const*)(a))
/*
* Interface defines not associated with particular options
*/
ntp_keygenOptions.pzCurOpt = NULL)
#define START_OPT RESTART_OPT(1)
#define USAGE(c) (*ntp_keygenOptions.pUsageProc)(&ntp_keygenOptions, c)
-/* extracted from opthead.tlib near line 484 */
+/* extracted from opthead.tlib near line 497 */
#ifdef __cplusplus
extern "C" {
-.TH ntp-keygen 1ntp-keygenman "02 Jan 2013" "ntp (4.2.7p343)" "User Commands"
+.TH ntp-keygen 1ntp-keygenman "03 Jan 2013" "ntp (4.2.7p344)" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntp-keygen-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:21:04 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:11:02 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp-keygen-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntp-keygen
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..."
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..."
.PP
All arguments must be options.
.PP
.SH DESCRIPTION
+This program generates cryptographic data files used by the NTPv4
+authentication and identification schemes.
+It generates MD5 key files used in symmetric key cryptography.
+In addition, if the OpenSSL software library has been installed,
+it generates keys, certificate and identity files used in public key
+cryptography.
+These files are used for cookie encryption,
+digital signature and challenge/response identification algorithms
+compatible with the Internet standard security infrastructure.
+.PP
+All files are in PEM-encoded printable ASCII format,
+so they can be embedded as MIME attachments in mail to other sites
+and certificate authorities.
+By default, files are not encrypted.
+.PP
+When used to generate message digest keys, the program produces a file
+containing ten pseudo-random printable ASCII strings suitable for the
+MD5 message digest algorithm included in the distribution.
+If the OpenSSL library is installed, it produces an additional ten
+hex-encoded random bit strings suitable for the SHA1 and other message
+digest algorithms.
+The message digest keys file must be distributed and stored
+using secure means beyond the scope of NTP itself.
+Besides the keys used for ordinary NTP associations, additional keys
+can be defined as passwords for the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+utility programs.
+.PP
+The remaining generated files are compatible with other OpenSSL
+applications and other Public Key Infrastructure (PKI) resources.
+Certificates generated by this program are compatible with extant
+industry practice, although some users might find the interpretation of
+X509v3 extension fields somewhat liberal.
+However, the identity keys are probably not compatible with anything
+other than Autokey.
+.PP
+Some files used by this program are encrypted using a private password.
+The
+p
+option specifies the password for local encrypted files and the
+q
+option the password for encrypted files sent to remote sites.
+If no password is specified, the host name returned by the Unix
+.Fn gethostname
+function, normally the DNS name of the host is used.
+.PP
+The
+\fIpw\fR
+option of the
+\fIcrypto\fR
+configuration command specifies the read
+password for previously encrypted local files.
+This must match the local password used by this program.
+If not specified, the host name is used.
+Thus, if files are generated by this program without password,
+they can be read back by
+\fIntpd\fR
+without password but only on the same host.
+.PP
+Normally, encrypted files for each host are generated by that host and
+used only by that host, although exceptions exist as noted later on
+this page.
+The symmetric keys file, normally called
+\fIntp.keys ,\fR
+is usually installed in
+.Pa /etc .
+Other files and links are usually installed in
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem in
+NFS-mounted networks and cannot be changed by shared clients.
+The location of the keys directory can be changed by the
+\fIkeysdir\fR
+configuration command in such cases.
+Normally, this is in
+.Pa /etc .
+.PP
+This program directs commentary and error messages to the standard
+error stream
+\fIstderr\fR
+and remote files to the standard output stream
+\fIstdout\fR
+where they can be piped to other applications or redirected to files.
+The names used for generated files and links all begin with the
+string
+\fIntpkey\fR
+and include the file type, generating host and filestamp,
+as described in the
+.Dq Cryptographic Data Files
+section below.
+.SS Running the Program
+To test and gain experience with Autokey concepts, log in as root and
+change to the keys directory, usually
+.Pa /usr/local/etc
+When run for the first time, or if all files with names beginning with
+\fIntpkey\fR
+have been removed, use the
+.B
+command without arguments to generate a
+default RSA host key and matching RSA-MD5 certificate with expiration
+date one year hence.
+If run again without options, the program uses the
+existing keys and parameters and generates only a new certificate with
+new expiration date one year hence.
+.PP
+Run the command on as many hosts as necessary.
+Designate one of them as the trusted host (TH) using
+.B
+with the
+T
+option and configure it to synchronize from reliable Internet servers.
+Then configure the other hosts to synchronize to the TH directly or
+indirectly.
+A certificate trail is created when Autokey asks the immediately
+ascendant host towards the TH to sign its certificate, which is then
+provided to the immediately descendant host on request.
+All group hosts should have acyclic certificate trails ending on the TH.
+.PP
+The host key is used to encrypt the cookie when required and so must be
+RSA type.
+By default, the host key is also the sign key used to encrypt
+signatures.
+A different sign key can be assigned using the
+S
+option and this can be either RSA or DSA type.
+By default, the signature
+message digest type is MD5, but any combination of sign key type and
+message digest type supported by the OpenSSL library can be specified
+using the
+c
+option.
+The rules say cryptographic media should be generated with proventic
+filestamps, which means the host should already be synchronized before
+this program is run.
+This of course creates a chicken-and-egg problem
+when the host is started for the first time.
+Accordingly, the host time
+should be set by some other means, such as eyeball-and-wristwatch, at
+least so that the certificate lifetime is within the current year.
+After that and when the host is synchronized to a proventic source, the
+certificate should be re-generated.
+.PP
+Additional information on trusted groups and identity schemes is on the
+.Dq Autokey Public-Key Authentication
+page.
+.PP
+The
+.Xr ntpd 1ntpdmdoc
+configuration command
+.Ic crypto pw Ar password
+specifies the read password for previously encrypted files.
+The daemon expires on the spot if the password is missing
+or incorrect.
+For convenience, if a file has been previously encrypted,
+the default read password is the name of the host running
+the program.
+If the previous write password is specified as the host name,
+these files can be read by that host with no explicit password.
+.PP
+File names begin with the prefix
+.Cm ntpkey_
+and end with the postfix
+\fI_hostname.filestamp ,\fR
+where
+\fIhostname\fR
+is the owner name, usually the string returned
+by the Unix gethostname() routine, and
+\fIfilestamp\fR
+is the NTP seconds when the file was generated, in decimal digits.
+This both guarantees uniqueness and simplifies maintenance
+procedures, since all files can be quickly removed
+by a
+.Ic rm ntpkey\&*
+command or all files generated
+at a specific time can be removed by a
+.Ic rm
+\fI\&*filestamp\fR
+command.
+To further reduce the risk of misconfiguration,
+the first two lines of a file contain the file name
+and generation date and time as comments.
+.PP
+All files are installed by default in the keys directory
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem
+in NFS-mounted networks.
+The actual location of the keys directory
+and each file can be overridden by configuration commands,
+but this is not recommended.
+Normally, the files for each host are generated by that host
+and used only by that host, although exceptions exist
+as noted later on this page.
+.PP
+Normally, files containing private values,
+including the host key, sign key and identification parameters,
+are permitted root read/write-only;
+while others containing public values are permitted world readable.
+Alternatively, files containing private values can be encrypted
+and these files permitted world readable,
+which simplifies maintenance in shared file systems.
+Since uniqueness is insured by the hostname and
+file name extensions, the files for a NFS server and
+dependent clients can all be installed in the same shared directory.
+.PP
+The recommended practice is to keep the file name extensions
+when installing a file and to install a soft link
+from the generic names specified elsewhere on this page
+to the generated files.
+This allows new file generations to be activated simply
+by changing the link.
+If a link is present, ntpd follows it to the file name
+to extract the filestamp.
+If a link is not present,
+.Xr ntpd 1ntpdmdoc
+extracts the filestamp from the file itself.
+This allows clients to verify that the file and generation times
+are always current.
+The
+.B
+program uses the same timestamp extension for all files generated
+at one time, so each generation is distinct and can be readily
+recognized in monitoring data.
+.SS Running the program
+The safest way to run the
+.B
+program is logged in directly as root.
+The recommended procedure is change to the keys directory,
+usually
+.Pa /usr/local/etc ,
+then run the program.
+When run for the first time,
+or if all
+.Cm ntpkey
+files have been removed,
+the program generates a RSA host key file and matching RSA-MD5 certificate file,
+which is all that is necessary in many cases.
+The program also generates soft links from the generic names
+to the respective files.
+If run again, the program uses the same host key file,
+but generates a new certificate file and link.
+.PP
+The host key is used to encrypt the cookie when required and so must be RSA type.
+By default, the host key is also the sign key used to encrypt signatures.
+When necessary, a different sign key can be specified and this can be
+either RSA or DSA type.
+By default, the message digest type is MD5, but any combination
+of sign key type and message digest type supported by the OpenSSL library
+can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2
+and RIPE160 message digest algorithms.
+However, the scheme specified in the certificate must be compatible
+with the sign key.
+Certificates using any digest algorithm are compatible with RSA sign keys;
+however, only SHA and SHA1 certificates are compatible with DSA sign keys.
+.PP
+Private/public key files and certificates are compatible with
+other OpenSSL applications and very likely other libraries as well.
+Certificates or certificate requests derived from them should be compatible
+with extant industry practice, although some users might find
+the interpretation of X509v3 extension fields somewhat liberal.
+However, the identification parameter files, although encoded
+as the other files, are probably not compatible with anything other than Autokey.
+.PP
+Running the program as other than root and using the Unix
+.Ic su
+command
+to assume root may not work properly, since by default the OpenSSL library
+looks for the random seed file
+.Cm .rnd
+in the user home directory.
+However, there should be only one
+.Cm .rnd ,
+most conveniently
+in the root directory, so it is convenient to define the
+.Cm $RANDFILE
+environment variable used by the OpenSSL library as the path to
+.Cm /.rnd .
+.PP
+Installing the keys as root might not work in NFS-mounted
+shared file systems, as NFS clients may not be able to write
+to the shared keys directory, even as root.
+In this case, NFS clients can specify the files in another
+directory such as
+.Pa /etc
+using the
+.Ic keysdir
+command.
+There is no need for one client to read the keys and certificates
+of other clients or servers, as these data are obtained automatically
+by the Autokey protocol.
+.PP
+Ordinarily, cryptographic files are generated by the host that uses them,
+but it is possible for a trusted agent (TA) to generate these files
+for other hosts; however, in such cases files should always be encrypted.
+The subject name and trusted name default to the hostname
+of the host generating the files, but can be changed by command line options.
+It is convenient to designate the owner name and trusted name
+as the subject and issuer fields, respectively, of the certificate.
+The owner name is also used for the host and sign key files,
+while the trusted name is used for the identity files.
+.PP
+All files are installed by default in the keys directory
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem
+in NFS-mounted networks.
+The actual location of the keys directory
+and each file can be overridden by configuration commands,
+but this is not recommended.
+Normally, the files for each host are generated by that host
+and used only by that host, although exceptions exist
+as noted later on this page.
+.PP
+Normally, files containing private values,
+including the host key, sign key and identification parameters,
+are permitted root read/write-only;
+while others containing public values are permitted world readable.
+Alternatively, files containing private values can be encrypted
+and these files permitted world readable,
+which simplifies maintenance in shared file systems.
+Since uniqueness is insured by the hostname and
+file name extensions, the files for a NFS server and
+dependent clients can all be installed in the same shared directory.
+.PP
+The recommended practice is to keep the file name extensions
+when installing a file and to install a soft link
+from the generic names specified elsewhere on this page
+to the generated files.
+This allows new file generations to be activated simply
+by changing the link.
+If a link is present, ntpd follows it to the file name
+to extract the filestamp.
+If a link is not present,
+.Xr ntpd 1ntpdmdoc
+extracts the filestamp from the file itself.
+This allows clients to verify that the file and generation times
+are always current.
+The
+.B
+program uses the same timestamp extension for all files generated
+at one time, so each generation is distinct and can be readily
+recognized in monitoring data.
+.SS Running the program
+The safest way to run the
+.B
+program is logged in directly as root.
+The recommended procedure is change to the keys directory,
+usually
+.Pa /usr/local/etc ,
+then run the program.
+When run for the first time,
+or if all
+.Cm ntpkey
+files have been removed,
+the program generates a RSA host key file and matching RSA-MD5 certificate file,
+which is all that is necessary in many cases.
+The program also generates soft links from the generic names
+to the respective files.
+If run again, the program uses the same host key file,
+but generates a new certificate file and link.
+.PP
+The host key is used to encrypt the cookie when required and so must be RSA type.
+By default, the host key is also the sign key used to encrypt signatures.
+When necessary, a different sign key can be specified and this can be
+either RSA or DSA type.
+By default, the message digest type is MD5, but any combination
+of sign key type and message digest type supported by the OpenSSL library
+can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2
+and RIPE160 message digest algorithms.
+However, the scheme specified in the certificate must be compatible
+with the sign key.
+Certificates using any digest algorithm are compatible with RSA sign keys;
+however, only SHA and SHA1 certificates are compatible with DSA sign keys.
+.PP
+Private/public key files and certificates are compatible with
+other OpenSSL applications and very likely other libraries as well.
+Certificates or certificate requests derived from them should be compatible
+with extant industry practice, although some users might find
+the interpretation of X509v3 extension fields somewhat liberal.
+However, the identification parameter files, although encoded
+as the other files, are probably not compatible with anything other than Autokey.
+.PP
+Running the program as other than root and using the Unix
+.Ic su
+command
+to assume root may not work properly, since by default the OpenSSL library
+looks for the random seed file
+.Cm .rnd
+in the user home directory.
+However, there should be only one
+.Cm .rnd ,
+most conveniently
+in the root directory, so it is convenient to define the
+.Cm $RANDFILE
+environment variable used by the OpenSSL library as the path to
+.Cm /.rnd .
+.PP
+Installing the keys as root might not work in NFS-mounted
+shared file systems, as NFS clients may not be able to write
+to the shared keys directory, even as root.
+In this case, NFS clients can specify the files in another
+directory such as
+.Pa /etc
+using the
+.Ic keysdir
+command.
+There is no need for one client to read the keys and certificates
+of other clients or servers, as these data are obtained automatically
+by the Autokey protocol.
+.PP
+Ordinarily, cryptographic files are generated by the host that uses them,
+but it is possible for a trusted agent (TA) to generate these files
+for other hosts; however, in such cases files should always be encrypted.
+The subject name and trusted name default to the hostname
+of the host generating the files, but can be changed by command line options.
+It is convenient to designate the owner name and trusted name
+as the subject and issuer fields, respectively, of the certificate.
+The owner name is also used for the host and sign key files,
+while the trusted name is used for the identity files.
+seconds.
+seconds.
+s Trusted Hosts and Groups
+Each cryptographic configuration involves selection of a signature scheme
+and identification scheme, called a cryptotype,
+as explained in the
+.Sx Authentication Options
+section of
+.Xr ntp.conf 5 .
+The default cryptotype uses RSA encryption, MD5 message digest
+and TC identification.
+First, configure a NTP subnet including one or more low-stratum
+trusted hosts from which all other hosts derive synchronization
+directly or indirectly.
+Trusted hosts have trusted certificates;
+all other hosts have nontrusted certificates.
+These hosts will automatically and dynamically build authoritative
+certificate trails to one or more trusted hosts.
+A trusted group is the set of all hosts that have, directly or indirectly,
+a certificate trail ending at a trusted host.
+The trail is defined by static configuration file entries
+or dynamic means described on the
+.Sx Automatic NTP Configuration Options
+section of
+.Xr ntp.conf 5 .
+.PP
+On each trusted host as root, change to the keys directory.
+To insure a fresh fileset, remove all
+.Cm ntpkey
+files.
+Then run
+.B
+T
+to generate keys and a trusted certificate.
+On all other hosts do the same, but leave off the
+T
+flag to generate keys and nontrusted certificates.
+When complete, start the NTP daemons beginning at the lowest stratum
+and working up the tree.
+It may take some time for Autokey to instantiate the certificate trails
+throughout the subnet, but setting up the environment is completely automatic.
+.PP
+If it is necessary to use a different sign key or different digest/signature
+scheme than the default, run
+.B
+with the
+S Ar type
+option, where
+\fItype\fR
+is either
+.Cm RSA
+or
+.Cm DSA .
+The most often need to do this is when a DSA-signed certificate is used.
+If it is necessary to use a different certificate scheme than the default,
+run
+.B
+with the
+c Ar scheme
+option and selected
+\fIscheme\fR
+as needed.
+f
+.B
+is run again without these options, it generates a new certificate
+using the same scheme and sign key.
+.PP
+After setting up the environment it is advisable to update certificates
+from time to time, if only to extend the validity interval.
+Simply run
+.B
+with the same flags as before to generate new certificates
+using existing keys.
+However, if the host or sign key is changed,
+.Xr ntpd 1ntpdmdoc
+should be restarted.
+When
+.Xr ntpd 1ntpdmdoc
+is restarted, it loads any new files and restarts the protocol.
+Other dependent hosts will continue as usual until signatures are refreshed,
+at which time the protocol is restarted.
+.SS Identity Schemes
+As mentioned on the Autonomous Authentication page,
+the default TC identity scheme is vulnerable to a middleman attack.
+However, there are more secure identity schemes available,
+including PC, IFF, GQ and MV described on the
+.Qq Identification Schemes
+page
+(maybe available at
+.Li http://www.eecis.udel.edu/%7emills/keygen.html ) .
+These schemes are based on a TA, one or more trusted hosts
+and some number of nontrusted hosts.
+Trusted hosts prove identity using values provided by the TA,
+while the remaining hosts prove identity using values provided
+by a trusted host and certificate trails that end on that host.
+The name of a trusted host is also the name of its sugroup
+and also the subject and issuer name on its trusted certificate.
+The TA is not necessarily a trusted host in this sense, but often is.
+.PP
+In some schemes there are separate keys for servers and clients.
+A server can also be a client of another server,
+but a client can never be a server for another client.
+In general, trusted hosts and nontrusted hosts that operate
+as both server and client have parameter files that contain
+both server and client keys.
+Hosts that operate
+only as clients have key files that contain only client keys.
+.PP
+The PC scheme supports only one trusted host in the group.
+On trusted host alice run
+.B
+P
+p Ar password
+to generate the host key file
+.Pa ntpkey_RSAkey_ Ns Ar alice.filestamp
+and trusted private certificate file
+.Pa ntpkey_RSA-MD5_cert_ Ns Ar alice.filestamp .
+Copy both files to all group hosts;
+they replace the files which would be generated in other schemes.
+On each host bob install a soft link from the generic name
+.Pa ntpkey_host_ Ns Ar bob
+to the host key file and soft link
+.Pa ntpkey_cert_ Ns Ar bob
+to the private certificate file.
+Note the generic links are on bob, but point to files generated
+by trusted host alice.
+In this scheme it is not possible to refresh
+either the keys or certificates without copying them
+to all other hosts in the group.
+.PP
+For the IFF scheme proceed as in the TC scheme to generate keys
+and certificates for all group hosts, then for every trusted host in the group,
+generate the IFF parameter file.
+On trusted host alice run
+.B
+T
+I
+p Ar password
+to produce her parameter file
+.Pa ntpkey_IFFpar_ Ns Ar alice.filestamp ,
+which includes both server and client keys.
+Copy this file to all group hosts that operate as both servers
+and clients and install a soft link from the generic
+.Pa ntpkey_iff_ Ns Ar alice
+to this file.
+If there are no hosts restricted to operate only as clients,
+there is nothing further to do.
+As the IFF scheme is independent
+of keys and certificates, these files can be refreshed as needed.
+.PP
+If a rogue client has the parameter file, it could masquerade
+as a legitimate server and present a middleman threat.
+To eliminate this threat, the client keys can be extracted
+from the parameter file and distributed to all restricted clients.
+After generating the parameter file, on alice run
+.B
+e
+and pipe the output to a file or mail program.
+Copy or mail this file to all restricted clients.
+On these clients install a soft link from the generic
+.Pa ntpkey_iff_ Ns Ar alice
+to this file.
+To further protect the integrity of the keys,
+each file can be encrypted with a secret password.
+.PP
+For the GQ scheme proceed as in the TC scheme to generate keys
+and certificates for all group hosts, then for every trusted host
+in the group, generate the IFF parameter file.
+On trusted host alice run
+.B
+T
+G
+p Ar password
+to produce her parameter file
+.Pa ntpkey_GQpar_ Ns Ar alice.filestamp ,
+which includes both server and client keys.
+Copy this file to all group hosts and install a soft link
+from the generic
+.Pa ntpkey_gq_ Ns Ar alice
+to this file.
+In addition, on each host bob install a soft link
+from generic
+.Pa ntpkey_gq_ Ns Ar bob
+to this file.
+As the GQ scheme updates the GQ parameters file and certificate
+at the same time, keys and certificates can be regenerated as needed.
+.PP
+For the MV scheme, proceed as in the TC scheme to generate keys
+and certificates for all group hosts.
+For illustration assume trish is the TA, alice one of several trusted hosts
+and bob one of her clients.
+On TA trish run
+.B
+V Ar n
+p Ar password ,
+where
+\fIn\fR
+is the number of revokable keys (typically 5) to produce
+the parameter file
+.Pa ntpkeys_MVpar_ Ns Ar trish.filestamp
+and client key files
+.Pa ntpkeys_MVkeyd_ Ns Ar trish.filestamp
+where
+\fId\fR
+is the key number (0 \&<
+\fId\fR
+\&<
+\fIn ) .\fR
+Copy the parameter file to alice and install a soft link
+from the generic
+.Pa ntpkey_mv_ Ns Ar alice
+to this file.
+Copy one of the client key files to alice for later distribution
+to her clients.
+It doesn't matter which client key file goes to alice,
+since they all work the same way.
+Alice copies the client key file to all of her cliens.
+On client bob install a soft link from generic
+.Pa ntpkey_mvkey_ Ns Ar bob
+to the client key file.
+As the MV scheme is independent of keys and certificates,
+these files can be refreshed as needed.
+.SS Command Line Options
+.TP
+.BR Fl c Ar scheme
+Select certificate message digest/signature encryption scheme.
+The
+\fIscheme\fR
+can be one of the following:
+. Cm RSA-MD2 , RSA-MD5 , RSA-SHA , RSA-SHA1 , RSA-MDC2 , RSA-RIPEMD160 , DSA-SHA ,
+or
+.Cm DSA-SHA1 .
+Note that RSA schemes must be used with a RSA sign key and DSA
+schemes must be used with a DSA sign key.
+The default without this option is
+.Cm RSA-MD5 .
+.TP
+.BR Fl d
+Enable debugging.
+This option displays the cryptographic data produced in eye-friendly billboards.
+.TP
+.BR Fl e
+Write the IFF client keys to the standard output.
+This is intended for automatic key distribution by mail.
+.TP
+.BR Fl G
+Generate parameters and keys for the GQ identification scheme,
+obsoleting any that may exist.
+.TP
+.BR Fl g
+Generate keys for the GQ identification scheme
+using the existing GQ parameters.
+If the GQ parameters do not yet exist, create them first.
+.TP
+.BR Fl H
+Generate new host keys, obsoleting any that may exist.
+.TP
+.BR Fl I
+Generate parameters for the IFF identification scheme,
+obsoleting any that may exist.
+.TP
+.BR Fl i Ar name
+Set the suject name to
+\fIname .\fR
+This is used as the subject field in certificates
+and in the file name for host and sign keys.
+.TP
+.BR Fl M
+Generate MD5 keys, obsoleting any that may exist.
+.TP
+.BR Fl P
+Generate a private certificate.
+By default, the program generates public certificates.
+.TP
+.BR Fl p Ar password
+Encrypt generated files containing private data with
+\fIpassword\fR
+and the DES-CBC algorithm.
+.TP
+.BR Fl q
+Set the password for reading files to password.
+.TP
+.BR Fl S Oo Cm RSA | DSA Oc
+Generate a new sign key of the designated type,
+obsoleting any that may exist.
+By default, the program uses the host key as the sign key.
+.TP
+.BR Fl s Ar name
+Set the issuer name to
+\fIname .\fR
+This is used for the issuer field in certificates
+and in the file name for identity files.
+.TP
+.BR Fl T
+Generate a trusted certificate.
+By default, the program generates a non-trusted certificate.
+.TP
+.BR Fl V Ar nkeys
+Generate parameters and keys for the Mu-Varadharajan (MV) identification scheme.
+.SS Random Seed File
+All cryptographically sound key generation schemes must have means
+to randomize the entropy seed used to initialize
+the internal pseudo-random number generator used
+by the library routines.
+The OpenSSL library uses a designated random seed file for this purpose.
+The file must be available when starting the NTP daemon and
+.B
+program.
+If a site supports OpenSSL or its companion OpenSSH,
+it is very likely that means to do this are already available.
+.PP
+It is important to understand that entropy must be evolved
+for each generation, for otherwise the random number sequence
+would be predictable.
+Various means dependent on external events, such as keystroke intervals,
+can be used to do this and some systems have built-in entropy sources.
+Suitable means are described in the OpenSSL software documentation,
+but are outside the scope of this page.
+.PP
+The entropy seed used by the OpenSSL library is contained in a file,
+usually called
+.Cm .rnd ,
+which must be available when starting the NTP daemon
+or the
+.B
+program.
+The NTP daemon will first look for the file
+using the path specified by the
+.Ic randfile
+subcommand of the
+.Ic crypto
+configuration command.
+If not specified in this way, or when starting the
+.B
+program,
+the OpenSSL library will look for the file using the path specified
+by the
+.Ev RANDFILE
+environment variable in the user home directory,
+whether root or some other user.
+If the
+.Ev RANDFILE
+environment variable is not present,
+the library will look for the
+.Cm .rnd
+file in the user home directory.
+If the file is not available or cannot be written,
+the daemon exits with a message to the system log and the program
+exits with a suitable error message.
+.SS Cryptographic Data Files
+All other file formats begin with two lines.
+The first contains the file name, including the generated host name
+and filestamp.
+The second contains the datestamp in conventional Unix date format.
+Lines beginning with # are considered comments and ignored by the
+.B
+program and
+.Xr ntpd 1ntpdmdoc
+daemon.
+Cryptographic values are encoded first using ASN.1 rules,
+then encrypted if necessary, and finally written PEM-encoded
+printable ASCII format preceded and followed by MIME content identifier lines.
+.PP
+The format of the symmetric keys file is somewhat different
+than the other files in the interest of backward compatibility.
+Since DES-CBC is deprecated in NTPv4, the only key format of interest
+is MD5 alphanumeric strings.
+Following hte heard the keys are
+entered one per line in the format
+.D1 Ar keyno type key
+where
+\fIkeyno\fR
+is a positive integer in the range 1-65,535,
+\fItype\fR
+is the string MD5 defining the key format and
+\fIkey\fR
+is the key itself,
+which is a printable ASCII string 16 characters or less in length.
+Each character is chosen from the 93 printable characters
+in the range 0x21 through 0x7f excluding space and the
+.Ql #
+character.
+.PP
+Note that the keys used by the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+programs
+are checked against passwords requested by the programs
+and entered by hand, so it is generally appropriate to specify these keys
+in human readable ASCII format.
+.PP
+The
+.B
+program generates a MD5 symmetric keys file
+.Pa ntpkey_MD5key_ Ns Ar hostname.filestamp .
+Since the file contains private shared keys,
+it should be visible only to root and distributed by secure means
+to other subnet hosts.
+The NTP daemon loads the file
+.Pa ntp.keys ,
+so
+.B
+installs a soft link from this name to the generated file.
+Subsequently, similar soft links must be installed by manual
+or automated means on the other subnet hosts.
+While this file is not used with the Autokey Version 2 protocol,
+it is needed to authenticate some remote configuration commands
+used by the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+utilities.
.SH "OPTIONS"
.TP
.BR \-b " \fIimbits\fP, " \-\-imbits "=" \fIimbits\fP
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.SH USAGE
+The
+p Ar password
+option specifies the write password and
+q Ar password
+option the read password for previously encrypted files.
+The
+.B
+program prompts for the password if it reads an encrypted file
+and the password is missing or incorrect.
+If an encrypted file is read successfully and
+no write password is specified, the read password is used
+as the write password by default.
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH "FILES"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+It can take quite a while to generate some cryptographic values,
+from one to several minutes with modern architectures
+such as UltraSPARC and up to tens of minutes to an hour
+with older architectures such as SPARC IPC.
+.PP
+Please report bugs to http://bugs.ntp.org .Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
+Portions of this document came from FreeBSD.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntp-keygen\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTP_KEYGEN 1ntp-keygenmdoc User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntp-keygen-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:21:11 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:11:11 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp-keygen-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
All arguments must be options.
.Pp
.Sh DESCRIPTION
+This program generates cryptographic data files used by the NTPv4
+authentication and identification schemes.
+It generates MD5 key files used in symmetric key cryptography.
+In addition, if the OpenSSL software library has been installed,
+it generates keys, certificate and identity files used in public key
+cryptography.
+These files are used for cookie encryption,
+digital signature and challenge/response identification algorithms
+compatible with the Internet standard security infrastructure.
+.Pp
+All files are in PEM-encoded printable ASCII format,
+so they can be embedded as MIME attachments in mail to other sites
+and certificate authorities.
+By default, files are not encrypted.
+.Pp
+When used to generate message digest keys, the program produces a file
+containing ten pseudo-random printable ASCII strings suitable for the
+MD5 message digest algorithm included in the distribution.
+If the OpenSSL library is installed, it produces an additional ten
+hex-encoded random bit strings suitable for the SHA1 and other message
+digest algorithms.
+The message digest keys file must be distributed and stored
+using secure means beyond the scope of NTP itself.
+Besides the keys used for ordinary NTP associations, additional keys
+can be defined as passwords for the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+utility programs.
+.Pp
+The remaining generated files are compatible with other OpenSSL
+applications and other Public Key Infrastructure (PKI) resources.
+Certificates generated by this program are compatible with extant
+industry practice, although some users might find the interpretation of
+X509v3 extension fields somewhat liberal.
+However, the identity keys are probably not compatible with anything
+other than Autokey.
+.Pp
+Some files used by this program are encrypted using a private password.
+The
+.Fl p
+option specifies the password for local encrypted files and the
+.Fl q
+option the password for encrypted files sent to remote sites.
+If no password is specified, the host name returned by the Unix
+.Fn gethostname
+function, normally the DNS name of the host is used.
+.Pp
+The
+.Ar pw
+option of the
+.Ar crypto
+configuration command specifies the read
+password for previously encrypted local files.
+This must match the local password used by this program.
+If not specified, the host name is used.
+Thus, if files are generated by this program without password,
+they can be read back by
+.Ar ntpd
+without password but only on the same host.
+.Pp
+Normally, encrypted files for each host are generated by that host and
+used only by that host, although exceptions exist as noted later on
+this page.
+The symmetric keys file, normally called
+.Ar ntp.keys ,
+is usually installed in
+.Pa /etc .
+Other files and links are usually installed in
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem in
+NFS-mounted networks and cannot be changed by shared clients.
+The location of the keys directory can be changed by the
+.Ar keysdir
+configuration command in such cases.
+Normally, this is in
+.Pa /etc .
+.Pp
+This program directs commentary and error messages to the standard
+error stream
+.Ar stderr
+and remote files to the standard output stream
+.Ar stdout
+where they can be piped to other applications or redirected to files.
+The names used for generated files and links all begin with the
+string
+.Ar ntpkey
+and include the file type, generating host and filestamp,
+as described in the
+.Dq Cryptographic Data Files
+section below.
+.Ss Running the Program
+To test and gain experience with Autokey concepts, log in as root and
+change to the keys directory, usually
+.Pa /usr/local/etc
+When run for the first time, or if all files with names beginning with
+.Ar ntpkey
+have been removed, use the
+.Nm
+command without arguments to generate a
+default RSA host key and matching RSA-MD5 certificate with expiration
+date one year hence.
+If run again without options, the program uses the
+existing keys and parameters and generates only a new certificate with
+new expiration date one year hence.
+.Pp
+Run the command on as many hosts as necessary.
+Designate one of them as the trusted host (TH) using
+.Nm
+with the
+.Fl T
+option and configure it to synchronize from reliable Internet servers.
+Then configure the other hosts to synchronize to the TH directly or
+indirectly.
+A certificate trail is created when Autokey asks the immediately
+ascendant host towards the TH to sign its certificate, which is then
+provided to the immediately descendant host on request.
+All group hosts should have acyclic certificate trails ending on the TH.
+.Pp
+The host key is used to encrypt the cookie when required and so must be
+RSA type.
+By default, the host key is also the sign key used to encrypt
+signatures.
+A different sign key can be assigned using the
+.Fl S
+option and this can be either RSA or DSA type.
+By default, the signature
+message digest type is MD5, but any combination of sign key type and
+message digest type supported by the OpenSSL library can be specified
+using the
+.Fl c
+option.
+The rules say cryptographic media should be generated with proventic
+filestamps, which means the host should already be synchronized before
+this program is run.
+This of course creates a chicken-and-egg problem
+when the host is started for the first time.
+Accordingly, the host time
+should be set by some other means, such as eyeball-and-wristwatch, at
+least so that the certificate lifetime is within the current year.
+After that and when the host is synchronized to a proventic source, the
+certificate should be re-generated.
+.Pp
+Additional information on trusted groups and identity schemes is on the
+.Dq Autokey Public-Key Authentication
+page.
+.Pp
+The
+.Xr ntpd 1ntpdmdoc
+configuration command
+.Ic crypto pw Ar password
+specifies the read password for previously encrypted files.
+The daemon expires on the spot if the password is missing
+or incorrect.
+For convenience, if a file has been previously encrypted,
+the default read password is the name of the host running
+the program.
+If the previous write password is specified as the host name,
+these files can be read by that host with no explicit password.
+.Pp
+File names begin with the prefix
+.Cm ntpkey_
+and end with the postfix
+.Ar _hostname.filestamp ,
+where
+.Ar hostname
+is the owner name, usually the string returned
+by the Unix gethostname() routine, and
+.Ar filestamp
+is the NTP seconds when the file was generated, in decimal digits.
+This both guarantees uniqueness and simplifies maintenance
+procedures, since all files can be quickly removed
+by a
+.Ic rm ntpkey\&*
+command or all files generated
+at a specific time can be removed by a
+.Ic rm
+.Ar \&*filestamp
+command.
+To further reduce the risk of misconfiguration,
+the first two lines of a file contain the file name
+and generation date and time as comments.
+.Pp
+All files are installed by default in the keys directory
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem
+in NFS-mounted networks.
+The actual location of the keys directory
+and each file can be overridden by configuration commands,
+but this is not recommended.
+Normally, the files for each host are generated by that host
+and used only by that host, although exceptions exist
+as noted later on this page.
+.Pp
+Normally, files containing private values,
+including the host key, sign key and identification parameters,
+are permitted root read/write-only;
+while others containing public values are permitted world readable.
+Alternatively, files containing private values can be encrypted
+and these files permitted world readable,
+which simplifies maintenance in shared file systems.
+Since uniqueness is insured by the hostname and
+file name extensions, the files for a NFS server and
+dependent clients can all be installed in the same shared directory.
+.Pp
+The recommended practice is to keep the file name extensions
+when installing a file and to install a soft link
+from the generic names specified elsewhere on this page
+to the generated files.
+This allows new file generations to be activated simply
+by changing the link.
+If a link is present, ntpd follows it to the file name
+to extract the filestamp.
+If a link is not present,
+.Xr ntpd 1ntpdmdoc
+extracts the filestamp from the file itself.
+This allows clients to verify that the file and generation times
+are always current.
+The
+.Nm
+program uses the same timestamp extension for all files generated
+at one time, so each generation is distinct and can be readily
+recognized in monitoring data.
+.Ss Running the program
+The safest way to run the
+.Nm
+program is logged in directly as root.
+The recommended procedure is change to the keys directory,
+usually
+.Pa /usr/local/etc ,
+then run the program.
+When run for the first time,
+or if all
+.Cm ntpkey
+files have been removed,
+the program generates a RSA host key file and matching RSA-MD5 certificate file,
+which is all that is necessary in many cases.
+The program also generates soft links from the generic names
+to the respective files.
+If run again, the program uses the same host key file,
+but generates a new certificate file and link.
+.Pp
+The host key is used to encrypt the cookie when required and so must be RSA type.
+By default, the host key is also the sign key used to encrypt signatures.
+When necessary, a different sign key can be specified and this can be
+either RSA or DSA type.
+By default, the message digest type is MD5, but any combination
+of sign key type and message digest type supported by the OpenSSL library
+can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2
+and RIPE160 message digest algorithms.
+However, the scheme specified in the certificate must be compatible
+with the sign key.
+Certificates using any digest algorithm are compatible with RSA sign keys;
+however, only SHA and SHA1 certificates are compatible with DSA sign keys.
+.Pp
+Private/public key files and certificates are compatible with
+other OpenSSL applications and very likely other libraries as well.
+Certificates or certificate requests derived from them should be compatible
+with extant industry practice, although some users might find
+the interpretation of X509v3 extension fields somewhat liberal.
+However, the identification parameter files, although encoded
+as the other files, are probably not compatible with anything other than Autokey.
+.Pp
+Running the program as other than root and using the Unix
+.Ic su
+command
+to assume root may not work properly, since by default the OpenSSL library
+looks for the random seed file
+.Cm .rnd
+in the user home directory.
+However, there should be only one
+.Cm .rnd ,
+most conveniently
+in the root directory, so it is convenient to define the
+.Cm $RANDFILE
+environment variable used by the OpenSSL library as the path to
+.Cm /.rnd .
+.Pp
+Installing the keys as root might not work in NFS-mounted
+shared file systems, as NFS clients may not be able to write
+to the shared keys directory, even as root.
+In this case, NFS clients can specify the files in another
+directory such as
+.Pa /etc
+using the
+.Ic keysdir
+command.
+There is no need for one client to read the keys and certificates
+of other clients or servers, as these data are obtained automatically
+by the Autokey protocol.
+.Pp
+Ordinarily, cryptographic files are generated by the host that uses them,
+but it is possible for a trusted agent (TA) to generate these files
+for other hosts; however, in such cases files should always be encrypted.
+The subject name and trusted name default to the hostname
+of the host generating the files, but can be changed by command line options.
+It is convenient to designate the owner name and trusted name
+as the subject and issuer fields, respectively, of the certificate.
+The owner name is also used for the host and sign key files,
+while the trusted name is used for the identity files.
+.Pp
+All files are installed by default in the keys directory
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem
+in NFS-mounted networks.
+The actual location of the keys directory
+and each file can be overridden by configuration commands,
+but this is not recommended.
+Normally, the files for each host are generated by that host
+and used only by that host, although exceptions exist
+as noted later on this page.
+.Pp
+Normally, files containing private values,
+including the host key, sign key and identification parameters,
+are permitted root read/write-only;
+while others containing public values are permitted world readable.
+Alternatively, files containing private values can be encrypted
+and these files permitted world readable,
+which simplifies maintenance in shared file systems.
+Since uniqueness is insured by the hostname and
+file name extensions, the files for a NFS server and
+dependent clients can all be installed in the same shared directory.
+.Pp
+The recommended practice is to keep the file name extensions
+when installing a file and to install a soft link
+from the generic names specified elsewhere on this page
+to the generated files.
+This allows new file generations to be activated simply
+by changing the link.
+If a link is present, ntpd follows it to the file name
+to extract the filestamp.
+If a link is not present,
+.Xr ntpd 1ntpdmdoc
+extracts the filestamp from the file itself.
+This allows clients to verify that the file and generation times
+are always current.
+The
+.Nm
+program uses the same timestamp extension for all files generated
+at one time, so each generation is distinct and can be readily
+recognized in monitoring data.
+.Ss Running the program
+The safest way to run the
+.Nm
+program is logged in directly as root.
+The recommended procedure is change to the keys directory,
+usually
+.Pa /usr/local/etc ,
+then run the program.
+When run for the first time,
+or if all
+.Cm ntpkey
+files have been removed,
+the program generates a RSA host key file and matching RSA-MD5 certificate file,
+which is all that is necessary in many cases.
+The program also generates soft links from the generic names
+to the respective files.
+If run again, the program uses the same host key file,
+but generates a new certificate file and link.
+.Pp
+The host key is used to encrypt the cookie when required and so must be RSA type.
+By default, the host key is also the sign key used to encrypt signatures.
+When necessary, a different sign key can be specified and this can be
+either RSA or DSA type.
+By default, the message digest type is MD5, but any combination
+of sign key type and message digest type supported by the OpenSSL library
+can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2
+and RIPE160 message digest algorithms.
+However, the scheme specified in the certificate must be compatible
+with the sign key.
+Certificates using any digest algorithm are compatible with RSA sign keys;
+however, only SHA and SHA1 certificates are compatible with DSA sign keys.
+.Pp
+Private/public key files and certificates are compatible with
+other OpenSSL applications and very likely other libraries as well.
+Certificates or certificate requests derived from them should be compatible
+with extant industry practice, although some users might find
+the interpretation of X509v3 extension fields somewhat liberal.
+However, the identification parameter files, although encoded
+as the other files, are probably not compatible with anything other than Autokey.
+.Pp
+Running the program as other than root and using the Unix
+.Ic su
+command
+to assume root may not work properly, since by default the OpenSSL library
+looks for the random seed file
+.Cm .rnd
+in the user home directory.
+However, there should be only one
+.Cm .rnd ,
+most conveniently
+in the root directory, so it is convenient to define the
+.Cm $RANDFILE
+environment variable used by the OpenSSL library as the path to
+.Cm /.rnd .
+.Pp
+Installing the keys as root might not work in NFS-mounted
+shared file systems, as NFS clients may not be able to write
+to the shared keys directory, even as root.
+In this case, NFS clients can specify the files in another
+directory such as
+.Pa /etc
+using the
+.Ic keysdir
+command.
+There is no need for one client to read the keys and certificates
+of other clients or servers, as these data are obtained automatically
+by the Autokey protocol.
+.Pp
+Ordinarily, cryptographic files are generated by the host that uses them,
+but it is possible for a trusted agent (TA) to generate these files
+for other hosts; however, in such cases files should always be encrypted.
+The subject name and trusted name default to the hostname
+of the host generating the files, but can be changed by command line options.
+It is convenient to designate the owner name and trusted name
+as the subject and issuer fields, respectively, of the certificate.
+The owner name is also used for the host and sign key files,
+while the trusted name is used for the identity files.
+seconds.
+seconds.
+s Trusted Hosts and Groups
+Each cryptographic configuration involves selection of a signature scheme
+and identification scheme, called a cryptotype,
+as explained in the
+.Sx Authentication Options
+section of
+.Xr ntp.conf 5 .
+The default cryptotype uses RSA encryption, MD5 message digest
+and TC identification.
+First, configure a NTP subnet including one or more low-stratum
+trusted hosts from which all other hosts derive synchronization
+directly or indirectly.
+Trusted hosts have trusted certificates;
+all other hosts have nontrusted certificates.
+These hosts will automatically and dynamically build authoritative
+certificate trails to one or more trusted hosts.
+A trusted group is the set of all hosts that have, directly or indirectly,
+a certificate trail ending at a trusted host.
+The trail is defined by static configuration file entries
+or dynamic means described on the
+.Sx Automatic NTP Configuration Options
+section of
+.Xr ntp.conf 5 .
+.Pp
+On each trusted host as root, change to the keys directory.
+To insure a fresh fileset, remove all
+.Cm ntpkey
+files.
+Then run
+.Nm
+.Fl T
+to generate keys and a trusted certificate.
+On all other hosts do the same, but leave off the
+.Fl T
+flag to generate keys and nontrusted certificates.
+When complete, start the NTP daemons beginning at the lowest stratum
+and working up the tree.
+It may take some time for Autokey to instantiate the certificate trails
+throughout the subnet, but setting up the environment is completely automatic.
+.Pp
+If it is necessary to use a different sign key or different digest/signature
+scheme than the default, run
+.Nm
+with the
+.Fl S Ar type
+option, where
+.Ar type
+is either
+.Cm RSA
+or
+.Cm DSA .
+The most often need to do this is when a DSA-signed certificate is used.
+If it is necessary to use a different certificate scheme than the default,
+run
+.Nm
+with the
+.Fl c Ar scheme
+option and selected
+.Ar scheme
+as needed.
+f
+.Nm
+is run again without these options, it generates a new certificate
+using the same scheme and sign key.
+.Pp
+After setting up the environment it is advisable to update certificates
+from time to time, if only to extend the validity interval.
+Simply run
+.Nm
+with the same flags as before to generate new certificates
+using existing keys.
+However, if the host or sign key is changed,
+.Xr ntpd 1ntpdmdoc
+should be restarted.
+When
+.Xr ntpd 1ntpdmdoc
+is restarted, it loads any new files and restarts the protocol.
+Other dependent hosts will continue as usual until signatures are refreshed,
+at which time the protocol is restarted.
+.Ss Identity Schemes
+As mentioned on the Autonomous Authentication page,
+the default TC identity scheme is vulnerable to a middleman attack.
+However, there are more secure identity schemes available,
+including PC, IFF, GQ and MV described on the
+.Qq Identification Schemes
+page
+(maybe available at
+.Li http://www.eecis.udel.edu/%7emills/keygen.html ) .
+These schemes are based on a TA, one or more trusted hosts
+and some number of nontrusted hosts.
+Trusted hosts prove identity using values provided by the TA,
+while the remaining hosts prove identity using values provided
+by a trusted host and certificate trails that end on that host.
+The name of a trusted host is also the name of its sugroup
+and also the subject and issuer name on its trusted certificate.
+The TA is not necessarily a trusted host in this sense, but often is.
+.Pp
+In some schemes there are separate keys for servers and clients.
+A server can also be a client of another server,
+but a client can never be a server for another client.
+In general, trusted hosts and nontrusted hosts that operate
+as both server and client have parameter files that contain
+both server and client keys.
+Hosts that operate
+only as clients have key files that contain only client keys.
+.Pp
+The PC scheme supports only one trusted host in the group.
+On trusted host alice run
+.Nm
+.Fl P
+.Fl p Ar password
+to generate the host key file
+.Pa ntpkey_RSAkey_ Ns Ar alice.filestamp
+and trusted private certificate file
+.Pa ntpkey_RSA-MD5_cert_ Ns Ar alice.filestamp .
+Copy both files to all group hosts;
+they replace the files which would be generated in other schemes.
+On each host bob install a soft link from the generic name
+.Pa ntpkey_host_ Ns Ar bob
+to the host key file and soft link
+.Pa ntpkey_cert_ Ns Ar bob
+to the private certificate file.
+Note the generic links are on bob, but point to files generated
+by trusted host alice.
+In this scheme it is not possible to refresh
+either the keys or certificates without copying them
+to all other hosts in the group.
+.Pp
+For the IFF scheme proceed as in the TC scheme to generate keys
+and certificates for all group hosts, then for every trusted host in the group,
+generate the IFF parameter file.
+On trusted host alice run
+.Nm
+.Fl T
+.Fl I
+.Fl p Ar password
+to produce her parameter file
+.Pa ntpkey_IFFpar_ Ns Ar alice.filestamp ,
+which includes both server and client keys.
+Copy this file to all group hosts that operate as both servers
+and clients and install a soft link from the generic
+.Pa ntpkey_iff_ Ns Ar alice
+to this file.
+If there are no hosts restricted to operate only as clients,
+there is nothing further to do.
+As the IFF scheme is independent
+of keys and certificates, these files can be refreshed as needed.
+.Pp
+If a rogue client has the parameter file, it could masquerade
+as a legitimate server and present a middleman threat.
+To eliminate this threat, the client keys can be extracted
+from the parameter file and distributed to all restricted clients.
+After generating the parameter file, on alice run
+.Nm
+.Fl e
+and pipe the output to a file or mail program.
+Copy or mail this file to all restricted clients.
+On these clients install a soft link from the generic
+.Pa ntpkey_iff_ Ns Ar alice
+to this file.
+To further protect the integrity of the keys,
+each file can be encrypted with a secret password.
+.Pp
+For the GQ scheme proceed as in the TC scheme to generate keys
+and certificates for all group hosts, then for every trusted host
+in the group, generate the IFF parameter file.
+On trusted host alice run
+.Nm
+.Fl T
+.Fl G
+.Fl p Ar password
+to produce her parameter file
+.Pa ntpkey_GQpar_ Ns Ar alice.filestamp ,
+which includes both server and client keys.
+Copy this file to all group hosts and install a soft link
+from the generic
+.Pa ntpkey_gq_ Ns Ar alice
+to this file.
+In addition, on each host bob install a soft link
+from generic
+.Pa ntpkey_gq_ Ns Ar bob
+to this file.
+As the GQ scheme updates the GQ parameters file and certificate
+at the same time, keys and certificates can be regenerated as needed.
+.Pp
+For the MV scheme, proceed as in the TC scheme to generate keys
+and certificates for all group hosts.
+For illustration assume trish is the TA, alice one of several trusted hosts
+and bob one of her clients.
+On TA trish run
+.Nm
+.Fl V Ar n
+.Fl p Ar password ,
+where
+.Ar n
+is the number of revokable keys (typically 5) to produce
+the parameter file
+.Pa ntpkeys_MVpar_ Ns Ar trish.filestamp
+and client key files
+.Pa ntpkeys_MVkeyd_ Ns Ar trish.filestamp
+where
+.Ar d
+is the key number (0 \&<
+.Ar d
+\&<
+.Ar n ) .
+Copy the parameter file to alice and install a soft link
+from the generic
+.Pa ntpkey_mv_ Ns Ar alice
+to this file.
+Copy one of the client key files to alice for later distribution
+to her clients.
+It doesn't matter which client key file goes to alice,
+since they all work the same way.
+Alice copies the client key file to all of her cliens.
+On client bob install a soft link from generic
+.Pa ntpkey_mvkey_ Ns Ar bob
+to the client key file.
+As the MV scheme is independent of keys and certificates,
+these files can be refreshed as needed.
+.Ss Command Line Options
+.Bl -tag -width indent
+.It Fl c Ar scheme
+Select certificate message digest/signature encryption scheme.
+The
+.Ar scheme
+can be one of the following:
+. Cm RSA-MD2 , RSA-MD5 , RSA-SHA , RSA-SHA1 , RSA-MDC2 , RSA-RIPEMD160 , DSA-SHA ,
+or
+.Cm DSA-SHA1 .
+Note that RSA schemes must be used with a RSA sign key and DSA
+schemes must be used with a DSA sign key.
+The default without this option is
+.Cm RSA-MD5 .
+.It Fl d
+Enable debugging.
+This option displays the cryptographic data produced in eye-friendly billboards.
+.It Fl e
+Write the IFF client keys to the standard output.
+This is intended for automatic key distribution by mail.
+.It Fl G
+Generate parameters and keys for the GQ identification scheme,
+obsoleting any that may exist.
+.It Fl g
+Generate keys for the GQ identification scheme
+using the existing GQ parameters.
+If the GQ parameters do not yet exist, create them first.
+.It Fl H
+Generate new host keys, obsoleting any that may exist.
+.It Fl I
+Generate parameters for the IFF identification scheme,
+obsoleting any that may exist.
+.It Fl i Ar name
+Set the suject name to
+.Ar name .
+This is used as the subject field in certificates
+and in the file name for host and sign keys.
+.It Fl M
+Generate MD5 keys, obsoleting any that may exist.
+.It Fl P
+Generate a private certificate.
+By default, the program generates public certificates.
+.It Fl p Ar password
+Encrypt generated files containing private data with
+.Ar password
+and the DES-CBC algorithm.
+.It Fl q
+Set the password for reading files to password.
+.It Fl S Oo Cm RSA | DSA Oc
+Generate a new sign key of the designated type,
+obsoleting any that may exist.
+By default, the program uses the host key as the sign key.
+.It Fl s Ar name
+Set the issuer name to
+.Ar name .
+This is used for the issuer field in certificates
+and in the file name for identity files.
+.It Fl T
+Generate a trusted certificate.
+By default, the program generates a non-trusted certificate.
+.It Fl V Ar nkeys
+Generate parameters and keys for the Mu-Varadharajan (MV) identification scheme.
+.El
+.Ss Random Seed File
+All cryptographically sound key generation schemes must have means
+to randomize the entropy seed used to initialize
+the internal pseudo-random number generator used
+by the library routines.
+The OpenSSL library uses a designated random seed file for this purpose.
+The file must be available when starting the NTP daemon and
+.Nm
+program.
+If a site supports OpenSSL or its companion OpenSSH,
+it is very likely that means to do this are already available.
+.Pp
+It is important to understand that entropy must be evolved
+for each generation, for otherwise the random number sequence
+would be predictable.
+Various means dependent on external events, such as keystroke intervals,
+can be used to do this and some systems have built-in entropy sources.
+Suitable means are described in the OpenSSL software documentation,
+but are outside the scope of this page.
+.Pp
+The entropy seed used by the OpenSSL library is contained in a file,
+usually called
+.Cm .rnd ,
+which must be available when starting the NTP daemon
+or the
+.Nm
+program.
+The NTP daemon will first look for the file
+using the path specified by the
+.Ic randfile
+subcommand of the
+.Ic crypto
+configuration command.
+If not specified in this way, or when starting the
+.Nm
+program,
+the OpenSSL library will look for the file using the path specified
+by the
+.Ev RANDFILE
+environment variable in the user home directory,
+whether root or some other user.
+If the
+.Ev RANDFILE
+environment variable is not present,
+the library will look for the
+.Cm .rnd
+file in the user home directory.
+If the file is not available or cannot be written,
+the daemon exits with a message to the system log and the program
+exits with a suitable error message.
+.Ss Cryptographic Data Files
+All other file formats begin with two lines.
+The first contains the file name, including the generated host name
+and filestamp.
+The second contains the datestamp in conventional Unix date format.
+Lines beginning with # are considered comments and ignored by the
+.Nm
+program and
+.Xr ntpd 1ntpdmdoc
+daemon.
+Cryptographic values are encoded first using ASN.1 rules,
+then encrypted if necessary, and finally written PEM-encoded
+printable ASCII format preceded and followed by MIME content identifier lines.
+.Pp
+The format of the symmetric keys file is somewhat different
+than the other files in the interest of backward compatibility.
+Since DES-CBC is deprecated in NTPv4, the only key format of interest
+is MD5 alphanumeric strings.
+Following hte heard the keys are
+entered one per line in the format
+.D1 Ar keyno type key
+where
+.Ar keyno
+is a positive integer in the range 1-65,535,
+.Ar type
+is the string MD5 defining the key format and
+.Ar key
+is the key itself,
+which is a printable ASCII string 16 characters or less in length.
+Each character is chosen from the 93 printable characters
+in the range 0x21 through 0x7f excluding space and the
+.Ql #
+character.
+.Pp
+Note that the keys used by the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+programs
+are checked against passwords requested by the programs
+and entered by hand, so it is generally appropriate to specify these keys
+in human readable ASCII format.
+.Pp
+The
+.Nm
+program generates a MD5 symmetric keys file
+.Pa ntpkey_MD5key_ Ns Ar hostname.filestamp .
+Since the file contains private shared keys,
+it should be visible only to root and distributed by secure means
+to other subnet hosts.
+The NTP daemon loads the file
+.Pa ntp.keys ,
+so
+.Nm
+installs a soft link from this name to the generated file.
+Subsequently, similar soft links must be installed by manual
+or automated means on the other subnet hosts.
+While this file is not used with the Autokey Version 2 protocol,
+it is needed to authenticate some remote configuration commands
+used by the
+.Xr ntpq 1ntpqmdoc
+and
+.Xr ntpdc 1ntpdcmdoc
+utilities.
.Sh "OPTIONS"
.Bl -tag
.It \-b " \fIimbits\fP, " \-\-imbits "=" \fIimbits\fP
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.Sh USAGE
+The
+.Fl p Ar password
+option specifies the write password and
+.Fl q Ar password
+option the read password for previously encrypted files.
+The
+.Nm
+program prompts for the password if it reads an encrypted file
+and the password is missing or incorrect.
+If an encrypted file is read successfully and
+no write password is specified, the read password is used
+as the write password by default.
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh "FILES"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+It can take quite a while to generate some cryptographic values,
+from one to several minutes with modern architectures
+such as UltraSPARC and up to tens of minutes to an hour
+with older architectures such as SPARC IPC.
+.Pp
+Please report bugs to http://bugs.ntp.org .Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
+Portions of this document came from FreeBSD.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntp-keygen\fP
option definitions.
printable ASCII format so they can be embedded as MIME attachments in
mail to other sites.
- <p>This document applies to version 4.2.7p343 of <code>ntp-keygen</code>.
+ <p>This document applies to version 4.2.7p344 of <code>ntp-keygen</code>.
<div class="node">
<p><hr>
used to select the program, defaulting to <span class="file">more</span>. Both will exit
with a status code of 0.
-<pre class="example">ntp-keygen (ntp) - Create a NTP host key - Ver. 4.2.7p342
+<pre class="example">ntp-keygen (ntp) - Create a NTP host key - Ver. 4.2.7p343
USAGE: ntp-keygen [ -<flag> [<val>] | --<name>[{=| }<val>] ]...
Flg Arg Option-Name Description
-b Num imbits identity modulus bits
-.TH ntp-keygen @NTP_KEYGEN_MS@ "02 Jan 2013" "ntp (4.2.7p343)" "User Commands"
+.TH ntp-keygen @NTP_KEYGEN_MS@ "03 Jan 2013" "ntp (4.2.7p344)" "User Commands"
.\"
.\" EDIT THIS FILE WITH CAUTION (ntp-keygen-opts.man)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:21:04 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:11:02 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp-keygen-opts.def
.\" and the template file agman-cmd.tpl
.\"
.SH SYNOPSIS
.B ntp-keygen
.\" Mixture of short (flag) options and long options
-.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP " [[=| ]\fIvalue\fP]]..."
+.RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \-\-\fIopt\-name\fP "[[=| ]\fIvalue\fP]]..."
.PP
All arguments must be options.
.PP
.SH DESCRIPTION
+This program generates cryptographic data files used by the NTPv4
+authentication and identification schemes.
+It generates MD5 key files used in symmetric key cryptography.
+In addition, if the OpenSSL software library has been installed,
+it generates keys, certificate and identity files used in public key
+cryptography.
+These files are used for cookie encryption,
+digital signature and challenge/response identification algorithms
+compatible with the Internet standard security infrastructure.
+.PP
+All files are in PEM-encoded printable ASCII format,
+so they can be embedded as MIME attachments in mail to other sites
+and certificate authorities.
+By default, files are not encrypted.
+.PP
+When used to generate message digest keys, the program produces a file
+containing ten pseudo-random printable ASCII strings suitable for the
+MD5 message digest algorithm included in the distribution.
+If the OpenSSL library is installed, it produces an additional ten
+hex-encoded random bit strings suitable for the SHA1 and other message
+digest algorithms.
+The message digest keys file must be distributed and stored
+using secure means beyond the scope of NTP itself.
+Besides the keys used for ordinary NTP associations, additional keys
+can be defined as passwords for the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+utility programs.
+.PP
+The remaining generated files are compatible with other OpenSSL
+applications and other Public Key Infrastructure (PKI) resources.
+Certificates generated by this program are compatible with extant
+industry practice, although some users might find the interpretation of
+X509v3 extension fields somewhat liberal.
+However, the identity keys are probably not compatible with anything
+other than Autokey.
+.PP
+Some files used by this program are encrypted using a private password.
+The
+p
+option specifies the password for local encrypted files and the
+q
+option the password for encrypted files sent to remote sites.
+If no password is specified, the host name returned by the Unix
+.Fn gethostname
+function, normally the DNS name of the host is used.
+.PP
+The
+\fIpw\fR
+option of the
+\fIcrypto\fR
+configuration command specifies the read
+password for previously encrypted local files.
+This must match the local password used by this program.
+If not specified, the host name is used.
+Thus, if files are generated by this program without password,
+they can be read back by
+\fIntpd\fR
+without password but only on the same host.
+.PP
+Normally, encrypted files for each host are generated by that host and
+used only by that host, although exceptions exist as noted later on
+this page.
+The symmetric keys file, normally called
+\fIntp.keys ,\fR
+is usually installed in
+.Pa /etc .
+Other files and links are usually installed in
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem in
+NFS-mounted networks and cannot be changed by shared clients.
+The location of the keys directory can be changed by the
+\fIkeysdir\fR
+configuration command in such cases.
+Normally, this is in
+.Pa /etc .
+.PP
+This program directs commentary and error messages to the standard
+error stream
+\fIstderr\fR
+and remote files to the standard output stream
+\fIstdout\fR
+where they can be piped to other applications or redirected to files.
+The names used for generated files and links all begin with the
+string
+\fIntpkey\fR
+and include the file type, generating host and filestamp,
+as described in the
+.Dq Cryptographic Data Files
+section below.
+.SS Running the Program
+To test and gain experience with Autokey concepts, log in as root and
+change to the keys directory, usually
+.Pa /usr/local/etc
+When run for the first time, or if all files with names beginning with
+\fIntpkey\fR
+have been removed, use the
+.B
+command without arguments to generate a
+default RSA host key and matching RSA-MD5 certificate with expiration
+date one year hence.
+If run again without options, the program uses the
+existing keys and parameters and generates only a new certificate with
+new expiration date one year hence.
+.PP
+Run the command on as many hosts as necessary.
+Designate one of them as the trusted host (TH) using
+.B
+with the
+T
+option and configure it to synchronize from reliable Internet servers.
+Then configure the other hosts to synchronize to the TH directly or
+indirectly.
+A certificate trail is created when Autokey asks the immediately
+ascendant host towards the TH to sign its certificate, which is then
+provided to the immediately descendant host on request.
+All group hosts should have acyclic certificate trails ending on the TH.
+.PP
+The host key is used to encrypt the cookie when required and so must be
+RSA type.
+By default, the host key is also the sign key used to encrypt
+signatures.
+A different sign key can be assigned using the
+S
+option and this can be either RSA or DSA type.
+By default, the signature
+message digest type is MD5, but any combination of sign key type and
+message digest type supported by the OpenSSL library can be specified
+using the
+c
+option.
+The rules say cryptographic media should be generated with proventic
+filestamps, which means the host should already be synchronized before
+this program is run.
+This of course creates a chicken-and-egg problem
+when the host is started for the first time.
+Accordingly, the host time
+should be set by some other means, such as eyeball-and-wristwatch, at
+least so that the certificate lifetime is within the current year.
+After that and when the host is synchronized to a proventic source, the
+certificate should be re-generated.
+.PP
+Additional information on trusted groups and identity schemes is on the
+.Dq Autokey Public-Key Authentication
+page.
+.PP
+The
+.Xr ntpd @NTPD_MS@
+configuration command
+.Ic crypto pw Ar password
+specifies the read password for previously encrypted files.
+The daemon expires on the spot if the password is missing
+or incorrect.
+For convenience, if a file has been previously encrypted,
+the default read password is the name of the host running
+the program.
+If the previous write password is specified as the host name,
+these files can be read by that host with no explicit password.
+.PP
+File names begin with the prefix
+.Cm ntpkey_
+and end with the postfix
+\fI_hostname.filestamp ,\fR
+where
+\fIhostname\fR
+is the owner name, usually the string returned
+by the Unix gethostname() routine, and
+\fIfilestamp\fR
+is the NTP seconds when the file was generated, in decimal digits.
+This both guarantees uniqueness and simplifies maintenance
+procedures, since all files can be quickly removed
+by a
+.Ic rm ntpkey\&*
+command or all files generated
+at a specific time can be removed by a
+.Ic rm
+\fI\&*filestamp\fR
+command.
+To further reduce the risk of misconfiguration,
+the first two lines of a file contain the file name
+and generation date and time as comments.
+.PP
+All files are installed by default in the keys directory
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem
+in NFS-mounted networks.
+The actual location of the keys directory
+and each file can be overridden by configuration commands,
+but this is not recommended.
+Normally, the files for each host are generated by that host
+and used only by that host, although exceptions exist
+as noted later on this page.
+.PP
+Normally, files containing private values,
+including the host key, sign key and identification parameters,
+are permitted root read/write-only;
+while others containing public values are permitted world readable.
+Alternatively, files containing private values can be encrypted
+and these files permitted world readable,
+which simplifies maintenance in shared file systems.
+Since uniqueness is insured by the hostname and
+file name extensions, the files for a NFS server and
+dependent clients can all be installed in the same shared directory.
+.PP
+The recommended practice is to keep the file name extensions
+when installing a file and to install a soft link
+from the generic names specified elsewhere on this page
+to the generated files.
+This allows new file generations to be activated simply
+by changing the link.
+If a link is present, ntpd follows it to the file name
+to extract the filestamp.
+If a link is not present,
+.Xr ntpd @NTPD_MS@
+extracts the filestamp from the file itself.
+This allows clients to verify that the file and generation times
+are always current.
+The
+.B
+program uses the same timestamp extension for all files generated
+at one time, so each generation is distinct and can be readily
+recognized in monitoring data.
+.SS Running the program
+The safest way to run the
+.B
+program is logged in directly as root.
+The recommended procedure is change to the keys directory,
+usually
+.Pa /usr/local/etc ,
+then run the program.
+When run for the first time,
+or if all
+.Cm ntpkey
+files have been removed,
+the program generates a RSA host key file and matching RSA-MD5 certificate file,
+which is all that is necessary in many cases.
+The program also generates soft links from the generic names
+to the respective files.
+If run again, the program uses the same host key file,
+but generates a new certificate file and link.
+.PP
+The host key is used to encrypt the cookie when required and so must be RSA type.
+By default, the host key is also the sign key used to encrypt signatures.
+When necessary, a different sign key can be specified and this can be
+either RSA or DSA type.
+By default, the message digest type is MD5, but any combination
+of sign key type and message digest type supported by the OpenSSL library
+can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2
+and RIPE160 message digest algorithms.
+However, the scheme specified in the certificate must be compatible
+with the sign key.
+Certificates using any digest algorithm are compatible with RSA sign keys;
+however, only SHA and SHA1 certificates are compatible with DSA sign keys.
+.PP
+Private/public key files and certificates are compatible with
+other OpenSSL applications and very likely other libraries as well.
+Certificates or certificate requests derived from them should be compatible
+with extant industry practice, although some users might find
+the interpretation of X509v3 extension fields somewhat liberal.
+However, the identification parameter files, although encoded
+as the other files, are probably not compatible with anything other than Autokey.
+.PP
+Running the program as other than root and using the Unix
+.Ic su
+command
+to assume root may not work properly, since by default the OpenSSL library
+looks for the random seed file
+.Cm .rnd
+in the user home directory.
+However, there should be only one
+.Cm .rnd ,
+most conveniently
+in the root directory, so it is convenient to define the
+.Cm $RANDFILE
+environment variable used by the OpenSSL library as the path to
+.Cm /.rnd .
+.PP
+Installing the keys as root might not work in NFS-mounted
+shared file systems, as NFS clients may not be able to write
+to the shared keys directory, even as root.
+In this case, NFS clients can specify the files in another
+directory such as
+.Pa /etc
+using the
+.Ic keysdir
+command.
+There is no need for one client to read the keys and certificates
+of other clients or servers, as these data are obtained automatically
+by the Autokey protocol.
+.PP
+Ordinarily, cryptographic files are generated by the host that uses them,
+but it is possible for a trusted agent (TA) to generate these files
+for other hosts; however, in such cases files should always be encrypted.
+The subject name and trusted name default to the hostname
+of the host generating the files, but can be changed by command line options.
+It is convenient to designate the owner name and trusted name
+as the subject and issuer fields, respectively, of the certificate.
+The owner name is also used for the host and sign key files,
+while the trusted name is used for the identity files.
+.PP
+All files are installed by default in the keys directory
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem
+in NFS-mounted networks.
+The actual location of the keys directory
+and each file can be overridden by configuration commands,
+but this is not recommended.
+Normally, the files for each host are generated by that host
+and used only by that host, although exceptions exist
+as noted later on this page.
+.PP
+Normally, files containing private values,
+including the host key, sign key and identification parameters,
+are permitted root read/write-only;
+while others containing public values are permitted world readable.
+Alternatively, files containing private values can be encrypted
+and these files permitted world readable,
+which simplifies maintenance in shared file systems.
+Since uniqueness is insured by the hostname and
+file name extensions, the files for a NFS server and
+dependent clients can all be installed in the same shared directory.
+.PP
+The recommended practice is to keep the file name extensions
+when installing a file and to install a soft link
+from the generic names specified elsewhere on this page
+to the generated files.
+This allows new file generations to be activated simply
+by changing the link.
+If a link is present, ntpd follows it to the file name
+to extract the filestamp.
+If a link is not present,
+.Xr ntpd @NTPD_MS@
+extracts the filestamp from the file itself.
+This allows clients to verify that the file and generation times
+are always current.
+The
+.B
+program uses the same timestamp extension for all files generated
+at one time, so each generation is distinct and can be readily
+recognized in monitoring data.
+.SS Running the program
+The safest way to run the
+.B
+program is logged in directly as root.
+The recommended procedure is change to the keys directory,
+usually
+.Pa /usr/local/etc ,
+then run the program.
+When run for the first time,
+or if all
+.Cm ntpkey
+files have been removed,
+the program generates a RSA host key file and matching RSA-MD5 certificate file,
+which is all that is necessary in many cases.
+The program also generates soft links from the generic names
+to the respective files.
+If run again, the program uses the same host key file,
+but generates a new certificate file and link.
+.PP
+The host key is used to encrypt the cookie when required and so must be RSA type.
+By default, the host key is also the sign key used to encrypt signatures.
+When necessary, a different sign key can be specified and this can be
+either RSA or DSA type.
+By default, the message digest type is MD5, but any combination
+of sign key type and message digest type supported by the OpenSSL library
+can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2
+and RIPE160 message digest algorithms.
+However, the scheme specified in the certificate must be compatible
+with the sign key.
+Certificates using any digest algorithm are compatible with RSA sign keys;
+however, only SHA and SHA1 certificates are compatible with DSA sign keys.
+.PP
+Private/public key files and certificates are compatible with
+other OpenSSL applications and very likely other libraries as well.
+Certificates or certificate requests derived from them should be compatible
+with extant industry practice, although some users might find
+the interpretation of X509v3 extension fields somewhat liberal.
+However, the identification parameter files, although encoded
+as the other files, are probably not compatible with anything other than Autokey.
+.PP
+Running the program as other than root and using the Unix
+.Ic su
+command
+to assume root may not work properly, since by default the OpenSSL library
+looks for the random seed file
+.Cm .rnd
+in the user home directory.
+However, there should be only one
+.Cm .rnd ,
+most conveniently
+in the root directory, so it is convenient to define the
+.Cm $RANDFILE
+environment variable used by the OpenSSL library as the path to
+.Cm /.rnd .
+.PP
+Installing the keys as root might not work in NFS-mounted
+shared file systems, as NFS clients may not be able to write
+to the shared keys directory, even as root.
+In this case, NFS clients can specify the files in another
+directory such as
+.Pa /etc
+using the
+.Ic keysdir
+command.
+There is no need for one client to read the keys and certificates
+of other clients or servers, as these data are obtained automatically
+by the Autokey protocol.
+.PP
+Ordinarily, cryptographic files are generated by the host that uses them,
+but it is possible for a trusted agent (TA) to generate these files
+for other hosts; however, in such cases files should always be encrypted.
+The subject name and trusted name default to the hostname
+of the host generating the files, but can be changed by command line options.
+It is convenient to designate the owner name and trusted name
+as the subject and issuer fields, respectively, of the certificate.
+The owner name is also used for the host and sign key files,
+while the trusted name is used for the identity files.
+seconds.
+seconds.
+s Trusted Hosts and Groups
+Each cryptographic configuration involves selection of a signature scheme
+and identification scheme, called a cryptotype,
+as explained in the
+.Sx Authentication Options
+section of
+.Xr ntp.conf 5 .
+The default cryptotype uses RSA encryption, MD5 message digest
+and TC identification.
+First, configure a NTP subnet including one or more low-stratum
+trusted hosts from which all other hosts derive synchronization
+directly or indirectly.
+Trusted hosts have trusted certificates;
+all other hosts have nontrusted certificates.
+These hosts will automatically and dynamically build authoritative
+certificate trails to one or more trusted hosts.
+A trusted group is the set of all hosts that have, directly or indirectly,
+a certificate trail ending at a trusted host.
+The trail is defined by static configuration file entries
+or dynamic means described on the
+.Sx Automatic NTP Configuration Options
+section of
+.Xr ntp.conf 5 .
+.PP
+On each trusted host as root, change to the keys directory.
+To insure a fresh fileset, remove all
+.Cm ntpkey
+files.
+Then run
+.B
+T
+to generate keys and a trusted certificate.
+On all other hosts do the same, but leave off the
+T
+flag to generate keys and nontrusted certificates.
+When complete, start the NTP daemons beginning at the lowest stratum
+and working up the tree.
+It may take some time for Autokey to instantiate the certificate trails
+throughout the subnet, but setting up the environment is completely automatic.
+.PP
+If it is necessary to use a different sign key or different digest/signature
+scheme than the default, run
+.B
+with the
+S Ar type
+option, where
+\fItype\fR
+is either
+.Cm RSA
+or
+.Cm DSA .
+The most often need to do this is when a DSA-signed certificate is used.
+If it is necessary to use a different certificate scheme than the default,
+run
+.B
+with the
+c Ar scheme
+option and selected
+\fIscheme\fR
+as needed.
+f
+.B
+is run again without these options, it generates a new certificate
+using the same scheme and sign key.
+.PP
+After setting up the environment it is advisable to update certificates
+from time to time, if only to extend the validity interval.
+Simply run
+.B
+with the same flags as before to generate new certificates
+using existing keys.
+However, if the host or sign key is changed,
+.Xr ntpd @NTPD_MS@
+should be restarted.
+When
+.Xr ntpd @NTPD_MS@
+is restarted, it loads any new files and restarts the protocol.
+Other dependent hosts will continue as usual until signatures are refreshed,
+at which time the protocol is restarted.
+.SS Identity Schemes
+As mentioned on the Autonomous Authentication page,
+the default TC identity scheme is vulnerable to a middleman attack.
+However, there are more secure identity schemes available,
+including PC, IFF, GQ and MV described on the
+.Qq Identification Schemes
+page
+(maybe available at
+.Li http://www.eecis.udel.edu/%7emills/keygen.html ) .
+These schemes are based on a TA, one or more trusted hosts
+and some number of nontrusted hosts.
+Trusted hosts prove identity using values provided by the TA,
+while the remaining hosts prove identity using values provided
+by a trusted host and certificate trails that end on that host.
+The name of a trusted host is also the name of its sugroup
+and also the subject and issuer name on its trusted certificate.
+The TA is not necessarily a trusted host in this sense, but often is.
+.PP
+In some schemes there are separate keys for servers and clients.
+A server can also be a client of another server,
+but a client can never be a server for another client.
+In general, trusted hosts and nontrusted hosts that operate
+as both server and client have parameter files that contain
+both server and client keys.
+Hosts that operate
+only as clients have key files that contain only client keys.
+.PP
+The PC scheme supports only one trusted host in the group.
+On trusted host alice run
+.B
+P
+p Ar password
+to generate the host key file
+.Pa ntpkey_RSAkey_ Ns Ar alice.filestamp
+and trusted private certificate file
+.Pa ntpkey_RSA-MD5_cert_ Ns Ar alice.filestamp .
+Copy both files to all group hosts;
+they replace the files which would be generated in other schemes.
+On each host bob install a soft link from the generic name
+.Pa ntpkey_host_ Ns Ar bob
+to the host key file and soft link
+.Pa ntpkey_cert_ Ns Ar bob
+to the private certificate file.
+Note the generic links are on bob, but point to files generated
+by trusted host alice.
+In this scheme it is not possible to refresh
+either the keys or certificates without copying them
+to all other hosts in the group.
+.PP
+For the IFF scheme proceed as in the TC scheme to generate keys
+and certificates for all group hosts, then for every trusted host in the group,
+generate the IFF parameter file.
+On trusted host alice run
+.B
+T
+I
+p Ar password
+to produce her parameter file
+.Pa ntpkey_IFFpar_ Ns Ar alice.filestamp ,
+which includes both server and client keys.
+Copy this file to all group hosts that operate as both servers
+and clients and install a soft link from the generic
+.Pa ntpkey_iff_ Ns Ar alice
+to this file.
+If there are no hosts restricted to operate only as clients,
+there is nothing further to do.
+As the IFF scheme is independent
+of keys and certificates, these files can be refreshed as needed.
+.PP
+If a rogue client has the parameter file, it could masquerade
+as a legitimate server and present a middleman threat.
+To eliminate this threat, the client keys can be extracted
+from the parameter file and distributed to all restricted clients.
+After generating the parameter file, on alice run
+.B
+e
+and pipe the output to a file or mail program.
+Copy or mail this file to all restricted clients.
+On these clients install a soft link from the generic
+.Pa ntpkey_iff_ Ns Ar alice
+to this file.
+To further protect the integrity of the keys,
+each file can be encrypted with a secret password.
+.PP
+For the GQ scheme proceed as in the TC scheme to generate keys
+and certificates for all group hosts, then for every trusted host
+in the group, generate the IFF parameter file.
+On trusted host alice run
+.B
+T
+G
+p Ar password
+to produce her parameter file
+.Pa ntpkey_GQpar_ Ns Ar alice.filestamp ,
+which includes both server and client keys.
+Copy this file to all group hosts and install a soft link
+from the generic
+.Pa ntpkey_gq_ Ns Ar alice
+to this file.
+In addition, on each host bob install a soft link
+from generic
+.Pa ntpkey_gq_ Ns Ar bob
+to this file.
+As the GQ scheme updates the GQ parameters file and certificate
+at the same time, keys and certificates can be regenerated as needed.
+.PP
+For the MV scheme, proceed as in the TC scheme to generate keys
+and certificates for all group hosts.
+For illustration assume trish is the TA, alice one of several trusted hosts
+and bob one of her clients.
+On TA trish run
+.B
+V Ar n
+p Ar password ,
+where
+\fIn\fR
+is the number of revokable keys (typically 5) to produce
+the parameter file
+.Pa ntpkeys_MVpar_ Ns Ar trish.filestamp
+and client key files
+.Pa ntpkeys_MVkeyd_ Ns Ar trish.filestamp
+where
+\fId\fR
+is the key number (0 \&<
+\fId\fR
+\&<
+\fIn ) .\fR
+Copy the parameter file to alice and install a soft link
+from the generic
+.Pa ntpkey_mv_ Ns Ar alice
+to this file.
+Copy one of the client key files to alice for later distribution
+to her clients.
+It doesn't matter which client key file goes to alice,
+since they all work the same way.
+Alice copies the client key file to all of her cliens.
+On client bob install a soft link from generic
+.Pa ntpkey_mvkey_ Ns Ar bob
+to the client key file.
+As the MV scheme is independent of keys and certificates,
+these files can be refreshed as needed.
+.SS Command Line Options
+.TP
+.BR Fl c Ar scheme
+Select certificate message digest/signature encryption scheme.
+The
+\fIscheme\fR
+can be one of the following:
+. Cm RSA-MD2 , RSA-MD5 , RSA-SHA , RSA-SHA1 , RSA-MDC2 , RSA-RIPEMD160 , DSA-SHA ,
+or
+.Cm DSA-SHA1 .
+Note that RSA schemes must be used with a RSA sign key and DSA
+schemes must be used with a DSA sign key.
+The default without this option is
+.Cm RSA-MD5 .
+.TP
+.BR Fl d
+Enable debugging.
+This option displays the cryptographic data produced in eye-friendly billboards.
+.TP
+.BR Fl e
+Write the IFF client keys to the standard output.
+This is intended for automatic key distribution by mail.
+.TP
+.BR Fl G
+Generate parameters and keys for the GQ identification scheme,
+obsoleting any that may exist.
+.TP
+.BR Fl g
+Generate keys for the GQ identification scheme
+using the existing GQ parameters.
+If the GQ parameters do not yet exist, create them first.
+.TP
+.BR Fl H
+Generate new host keys, obsoleting any that may exist.
+.TP
+.BR Fl I
+Generate parameters for the IFF identification scheme,
+obsoleting any that may exist.
+.TP
+.BR Fl i Ar name
+Set the suject name to
+\fIname .\fR
+This is used as the subject field in certificates
+and in the file name for host and sign keys.
+.TP
+.BR Fl M
+Generate MD5 keys, obsoleting any that may exist.
+.TP
+.BR Fl P
+Generate a private certificate.
+By default, the program generates public certificates.
+.TP
+.BR Fl p Ar password
+Encrypt generated files containing private data with
+\fIpassword\fR
+and the DES-CBC algorithm.
+.TP
+.BR Fl q
+Set the password for reading files to password.
+.TP
+.BR Fl S Oo Cm RSA | DSA Oc
+Generate a new sign key of the designated type,
+obsoleting any that may exist.
+By default, the program uses the host key as the sign key.
+.TP
+.BR Fl s Ar name
+Set the issuer name to
+\fIname .\fR
+This is used for the issuer field in certificates
+and in the file name for identity files.
+.TP
+.BR Fl T
+Generate a trusted certificate.
+By default, the program generates a non-trusted certificate.
+.TP
+.BR Fl V Ar nkeys
+Generate parameters and keys for the Mu-Varadharajan (MV) identification scheme.
+.SS Random Seed File
+All cryptographically sound key generation schemes must have means
+to randomize the entropy seed used to initialize
+the internal pseudo-random number generator used
+by the library routines.
+The OpenSSL library uses a designated random seed file for this purpose.
+The file must be available when starting the NTP daemon and
+.B
+program.
+If a site supports OpenSSL or its companion OpenSSH,
+it is very likely that means to do this are already available.
+.PP
+It is important to understand that entropy must be evolved
+for each generation, for otherwise the random number sequence
+would be predictable.
+Various means dependent on external events, such as keystroke intervals,
+can be used to do this and some systems have built-in entropy sources.
+Suitable means are described in the OpenSSL software documentation,
+but are outside the scope of this page.
+.PP
+The entropy seed used by the OpenSSL library is contained in a file,
+usually called
+.Cm .rnd ,
+which must be available when starting the NTP daemon
+or the
+.B
+program.
+The NTP daemon will first look for the file
+using the path specified by the
+.Ic randfile
+subcommand of the
+.Ic crypto
+configuration command.
+If not specified in this way, or when starting the
+.B
+program,
+the OpenSSL library will look for the file using the path specified
+by the
+.Ev RANDFILE
+environment variable in the user home directory,
+whether root or some other user.
+If the
+.Ev RANDFILE
+environment variable is not present,
+the library will look for the
+.Cm .rnd
+file in the user home directory.
+If the file is not available or cannot be written,
+the daemon exits with a message to the system log and the program
+exits with a suitable error message.
+.SS Cryptographic Data Files
+All other file formats begin with two lines.
+The first contains the file name, including the generated host name
+and filestamp.
+The second contains the datestamp in conventional Unix date format.
+Lines beginning with # are considered comments and ignored by the
+.B
+program and
+.Xr ntpd @NTPD_MS@
+daemon.
+Cryptographic values are encoded first using ASN.1 rules,
+then encrypted if necessary, and finally written PEM-encoded
+printable ASCII format preceded and followed by MIME content identifier lines.
+.PP
+The format of the symmetric keys file is somewhat different
+than the other files in the interest of backward compatibility.
+Since DES-CBC is deprecated in NTPv4, the only key format of interest
+is MD5 alphanumeric strings.
+Following hte heard the keys are
+entered one per line in the format
+.D1 Ar keyno type key
+where
+\fIkeyno\fR
+is a positive integer in the range 1-65,535,
+\fItype\fR
+is the string MD5 defining the key format and
+\fIkey\fR
+is the key itself,
+which is a printable ASCII string 16 characters or less in length.
+Each character is chosen from the 93 printable characters
+in the range 0x21 through 0x7f excluding space and the
+.Ql #
+character.
+.PP
+Note that the keys used by the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+programs
+are checked against passwords requested by the programs
+and entered by hand, so it is generally appropriate to specify these keys
+in human readable ASCII format.
+.PP
+The
+.B
+program generates a MD5 symmetric keys file
+.Pa ntpkey_MD5key_ Ns Ar hostname.filestamp .
+Since the file contains private shared keys,
+it should be visible only to root and distributed by secure means
+to other subnet hosts.
+The NTP daemon loads the file
+.Pa ntp.keys ,
+so
+.B
+installs a soft link from this name to the generated file.
+Subsequently, similar soft links must be installed by manual
+or automated means on the other subnet hosts.
+While this file is not used with the Autokey Version 2 protocol,
+it is needed to authenticate some remote configuration commands
+used by the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+utilities.
.SH "OPTIONS"
.TP
.BR \-b " \fIimbits\fP, " \-\-imbits "=" \fIimbits\fP
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.SH USAGE
+The
+p Ar password
+option specifies the write password and
+q Ar password
+option the read password for previously encrypted files.
+The
+.B
+program prompts for the password if it reads an encrypted file
+and the password is missing or incorrect.
+If an encrypted file is read successfully and
+no write password is specified, the read password is used
+as the write password by default.
.SH "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.SH "FILES"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.SH BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+It can take quite a while to generate some cryptographic values,
+from one to several minutes with modern architectures
+such as UltraSPARC and up to tens of minutes to an hour
+with older architectures such as SPARC IPC.
+.PP
+Please report bugs to http://bugs.ntp.org .Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.SH NOTES
+This document corresponds to version @VERSION@ of NTP.
+Portions of this document came from FreeBSD.
.PP
This manual page was \fIAutoGen\fP-erated from the \fBntp-keygen\fP
option definitions.
-.Dd January 2 2013
+.Dd January 3 2013
.Dt NTP_KEYGEN @NTP_KEYGEN_MS@ User Commands
.Os SunOS 5.10
.\" EDIT THIS FILE WITH CAUTION (ntp-keygen-opts.mdoc)
.\"
-.\" It has been AutoGen-ed January 2, 2013 at 02:21:11 AM by AutoGen 5.16.2
+.\" It has been AutoGen-ed January 3, 2013 at 01:11:11 PM by AutoGen 5.17.1pre11
.\" From the definitions ntp-keygen-opts.def
.\" and the template file agmdoc-cmd.tpl
.Sh NAME
All arguments must be options.
.Pp
.Sh DESCRIPTION
+This program generates cryptographic data files used by the NTPv4
+authentication and identification schemes.
+It generates MD5 key files used in symmetric key cryptography.
+In addition, if the OpenSSL software library has been installed,
+it generates keys, certificate and identity files used in public key
+cryptography.
+These files are used for cookie encryption,
+digital signature and challenge/response identification algorithms
+compatible with the Internet standard security infrastructure.
+.Pp
+All files are in PEM-encoded printable ASCII format,
+so they can be embedded as MIME attachments in mail to other sites
+and certificate authorities.
+By default, files are not encrypted.
+.Pp
+When used to generate message digest keys, the program produces a file
+containing ten pseudo-random printable ASCII strings suitable for the
+MD5 message digest algorithm included in the distribution.
+If the OpenSSL library is installed, it produces an additional ten
+hex-encoded random bit strings suitable for the SHA1 and other message
+digest algorithms.
+The message digest keys file must be distributed and stored
+using secure means beyond the scope of NTP itself.
+Besides the keys used for ordinary NTP associations, additional keys
+can be defined as passwords for the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+utility programs.
+.Pp
+The remaining generated files are compatible with other OpenSSL
+applications and other Public Key Infrastructure (PKI) resources.
+Certificates generated by this program are compatible with extant
+industry practice, although some users might find the interpretation of
+X509v3 extension fields somewhat liberal.
+However, the identity keys are probably not compatible with anything
+other than Autokey.
+.Pp
+Some files used by this program are encrypted using a private password.
+The
+.Fl p
+option specifies the password for local encrypted files and the
+.Fl q
+option the password for encrypted files sent to remote sites.
+If no password is specified, the host name returned by the Unix
+.Fn gethostname
+function, normally the DNS name of the host is used.
+.Pp
+The
+.Ar pw
+option of the
+.Ar crypto
+configuration command specifies the read
+password for previously encrypted local files.
+This must match the local password used by this program.
+If not specified, the host name is used.
+Thus, if files are generated by this program without password,
+they can be read back by
+.Ar ntpd
+without password but only on the same host.
+.Pp
+Normally, encrypted files for each host are generated by that host and
+used only by that host, although exceptions exist as noted later on
+this page.
+The symmetric keys file, normally called
+.Ar ntp.keys ,
+is usually installed in
+.Pa /etc .
+Other files and links are usually installed in
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem in
+NFS-mounted networks and cannot be changed by shared clients.
+The location of the keys directory can be changed by the
+.Ar keysdir
+configuration command in such cases.
+Normally, this is in
+.Pa /etc .
+.Pp
+This program directs commentary and error messages to the standard
+error stream
+.Ar stderr
+and remote files to the standard output stream
+.Ar stdout
+where they can be piped to other applications or redirected to files.
+The names used for generated files and links all begin with the
+string
+.Ar ntpkey
+and include the file type, generating host and filestamp,
+as described in the
+.Dq Cryptographic Data Files
+section below.
+.Ss Running the Program
+To test and gain experience with Autokey concepts, log in as root and
+change to the keys directory, usually
+.Pa /usr/local/etc
+When run for the first time, or if all files with names beginning with
+.Ar ntpkey
+have been removed, use the
+.Nm
+command without arguments to generate a
+default RSA host key and matching RSA-MD5 certificate with expiration
+date one year hence.
+If run again without options, the program uses the
+existing keys and parameters and generates only a new certificate with
+new expiration date one year hence.
+.Pp
+Run the command on as many hosts as necessary.
+Designate one of them as the trusted host (TH) using
+.Nm
+with the
+.Fl T
+option and configure it to synchronize from reliable Internet servers.
+Then configure the other hosts to synchronize to the TH directly or
+indirectly.
+A certificate trail is created when Autokey asks the immediately
+ascendant host towards the TH to sign its certificate, which is then
+provided to the immediately descendant host on request.
+All group hosts should have acyclic certificate trails ending on the TH.
+.Pp
+The host key is used to encrypt the cookie when required and so must be
+RSA type.
+By default, the host key is also the sign key used to encrypt
+signatures.
+A different sign key can be assigned using the
+.Fl S
+option and this can be either RSA or DSA type.
+By default, the signature
+message digest type is MD5, but any combination of sign key type and
+message digest type supported by the OpenSSL library can be specified
+using the
+.Fl c
+option.
+The rules say cryptographic media should be generated with proventic
+filestamps, which means the host should already be synchronized before
+this program is run.
+This of course creates a chicken-and-egg problem
+when the host is started for the first time.
+Accordingly, the host time
+should be set by some other means, such as eyeball-and-wristwatch, at
+least so that the certificate lifetime is within the current year.
+After that and when the host is synchronized to a proventic source, the
+certificate should be re-generated.
+.Pp
+Additional information on trusted groups and identity schemes is on the
+.Dq Autokey Public-Key Authentication
+page.
+.Pp
+The
+.Xr ntpd @NTPD_MS@
+configuration command
+.Ic crypto pw Ar password
+specifies the read password for previously encrypted files.
+The daemon expires on the spot if the password is missing
+or incorrect.
+For convenience, if a file has been previously encrypted,
+the default read password is the name of the host running
+the program.
+If the previous write password is specified as the host name,
+these files can be read by that host with no explicit password.
+.Pp
+File names begin with the prefix
+.Cm ntpkey_
+and end with the postfix
+.Ar _hostname.filestamp ,
+where
+.Ar hostname
+is the owner name, usually the string returned
+by the Unix gethostname() routine, and
+.Ar filestamp
+is the NTP seconds when the file was generated, in decimal digits.
+This both guarantees uniqueness and simplifies maintenance
+procedures, since all files can be quickly removed
+by a
+.Ic rm ntpkey\&*
+command or all files generated
+at a specific time can be removed by a
+.Ic rm
+.Ar \&*filestamp
+command.
+To further reduce the risk of misconfiguration,
+the first two lines of a file contain the file name
+and generation date and time as comments.
+.Pp
+All files are installed by default in the keys directory
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem
+in NFS-mounted networks.
+The actual location of the keys directory
+and each file can be overridden by configuration commands,
+but this is not recommended.
+Normally, the files for each host are generated by that host
+and used only by that host, although exceptions exist
+as noted later on this page.
+.Pp
+Normally, files containing private values,
+including the host key, sign key and identification parameters,
+are permitted root read/write-only;
+while others containing public values are permitted world readable.
+Alternatively, files containing private values can be encrypted
+and these files permitted world readable,
+which simplifies maintenance in shared file systems.
+Since uniqueness is insured by the hostname and
+file name extensions, the files for a NFS server and
+dependent clients can all be installed in the same shared directory.
+.Pp
+The recommended practice is to keep the file name extensions
+when installing a file and to install a soft link
+from the generic names specified elsewhere on this page
+to the generated files.
+This allows new file generations to be activated simply
+by changing the link.
+If a link is present, ntpd follows it to the file name
+to extract the filestamp.
+If a link is not present,
+.Xr ntpd @NTPD_MS@
+extracts the filestamp from the file itself.
+This allows clients to verify that the file and generation times
+are always current.
+The
+.Nm
+program uses the same timestamp extension for all files generated
+at one time, so each generation is distinct and can be readily
+recognized in monitoring data.
+.Ss Running the program
+The safest way to run the
+.Nm
+program is logged in directly as root.
+The recommended procedure is change to the keys directory,
+usually
+.Pa /usr/local/etc ,
+then run the program.
+When run for the first time,
+or if all
+.Cm ntpkey
+files have been removed,
+the program generates a RSA host key file and matching RSA-MD5 certificate file,
+which is all that is necessary in many cases.
+The program also generates soft links from the generic names
+to the respective files.
+If run again, the program uses the same host key file,
+but generates a new certificate file and link.
+.Pp
+The host key is used to encrypt the cookie when required and so must be RSA type.
+By default, the host key is also the sign key used to encrypt signatures.
+When necessary, a different sign key can be specified and this can be
+either RSA or DSA type.
+By default, the message digest type is MD5, but any combination
+of sign key type and message digest type supported by the OpenSSL library
+can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2
+and RIPE160 message digest algorithms.
+However, the scheme specified in the certificate must be compatible
+with the sign key.
+Certificates using any digest algorithm are compatible with RSA sign keys;
+however, only SHA and SHA1 certificates are compatible with DSA sign keys.
+.Pp
+Private/public key files and certificates are compatible with
+other OpenSSL applications and very likely other libraries as well.
+Certificates or certificate requests derived from them should be compatible
+with extant industry practice, although some users might find
+the interpretation of X509v3 extension fields somewhat liberal.
+However, the identification parameter files, although encoded
+as the other files, are probably not compatible with anything other than Autokey.
+.Pp
+Running the program as other than root and using the Unix
+.Ic su
+command
+to assume root may not work properly, since by default the OpenSSL library
+looks for the random seed file
+.Cm .rnd
+in the user home directory.
+However, there should be only one
+.Cm .rnd ,
+most conveniently
+in the root directory, so it is convenient to define the
+.Cm $RANDFILE
+environment variable used by the OpenSSL library as the path to
+.Cm /.rnd .
+.Pp
+Installing the keys as root might not work in NFS-mounted
+shared file systems, as NFS clients may not be able to write
+to the shared keys directory, even as root.
+In this case, NFS clients can specify the files in another
+directory such as
+.Pa /etc
+using the
+.Ic keysdir
+command.
+There is no need for one client to read the keys and certificates
+of other clients or servers, as these data are obtained automatically
+by the Autokey protocol.
+.Pp
+Ordinarily, cryptographic files are generated by the host that uses them,
+but it is possible for a trusted agent (TA) to generate these files
+for other hosts; however, in such cases files should always be encrypted.
+The subject name and trusted name default to the hostname
+of the host generating the files, but can be changed by command line options.
+It is convenient to designate the owner name and trusted name
+as the subject and issuer fields, respectively, of the certificate.
+The owner name is also used for the host and sign key files,
+while the trusted name is used for the identity files.
+.Pp
+All files are installed by default in the keys directory
+.Pa /usr/local/etc ,
+which is normally in a shared filesystem
+in NFS-mounted networks.
+The actual location of the keys directory
+and each file can be overridden by configuration commands,
+but this is not recommended.
+Normally, the files for each host are generated by that host
+and used only by that host, although exceptions exist
+as noted later on this page.
+.Pp
+Normally, files containing private values,
+including the host key, sign key and identification parameters,
+are permitted root read/write-only;
+while others containing public values are permitted world readable.
+Alternatively, files containing private values can be encrypted
+and these files permitted world readable,
+which simplifies maintenance in shared file systems.
+Since uniqueness is insured by the hostname and
+file name extensions, the files for a NFS server and
+dependent clients can all be installed in the same shared directory.
+.Pp
+The recommended practice is to keep the file name extensions
+when installing a file and to install a soft link
+from the generic names specified elsewhere on this page
+to the generated files.
+This allows new file generations to be activated simply
+by changing the link.
+If a link is present, ntpd follows it to the file name
+to extract the filestamp.
+If a link is not present,
+.Xr ntpd @NTPD_MS@
+extracts the filestamp from the file itself.
+This allows clients to verify that the file and generation times
+are always current.
+The
+.Nm
+program uses the same timestamp extension for all files generated
+at one time, so each generation is distinct and can be readily
+recognized in monitoring data.
+.Ss Running the program
+The safest way to run the
+.Nm
+program is logged in directly as root.
+The recommended procedure is change to the keys directory,
+usually
+.Pa /usr/local/etc ,
+then run the program.
+When run for the first time,
+or if all
+.Cm ntpkey
+files have been removed,
+the program generates a RSA host key file and matching RSA-MD5 certificate file,
+which is all that is necessary in many cases.
+The program also generates soft links from the generic names
+to the respective files.
+If run again, the program uses the same host key file,
+but generates a new certificate file and link.
+.Pp
+The host key is used to encrypt the cookie when required and so must be RSA type.
+By default, the host key is also the sign key used to encrypt signatures.
+When necessary, a different sign key can be specified and this can be
+either RSA or DSA type.
+By default, the message digest type is MD5, but any combination
+of sign key type and message digest type supported by the OpenSSL library
+can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2
+and RIPE160 message digest algorithms.
+However, the scheme specified in the certificate must be compatible
+with the sign key.
+Certificates using any digest algorithm are compatible with RSA sign keys;
+however, only SHA and SHA1 certificates are compatible with DSA sign keys.
+.Pp
+Private/public key files and certificates are compatible with
+other OpenSSL applications and very likely other libraries as well.
+Certificates or certificate requests derived from them should be compatible
+with extant industry practice, although some users might find
+the interpretation of X509v3 extension fields somewhat liberal.
+However, the identification parameter files, although encoded
+as the other files, are probably not compatible with anything other than Autokey.
+.Pp
+Running the program as other than root and using the Unix
+.Ic su
+command
+to assume root may not work properly, since by default the OpenSSL library
+looks for the random seed file
+.Cm .rnd
+in the user home directory.
+However, there should be only one
+.Cm .rnd ,
+most conveniently
+in the root directory, so it is convenient to define the
+.Cm $RANDFILE
+environment variable used by the OpenSSL library as the path to
+.Cm /.rnd .
+.Pp
+Installing the keys as root might not work in NFS-mounted
+shared file systems, as NFS clients may not be able to write
+to the shared keys directory, even as root.
+In this case, NFS clients can specify the files in another
+directory such as
+.Pa /etc
+using the
+.Ic keysdir
+command.
+There is no need for one client to read the keys and certificates
+of other clients or servers, as these data are obtained automatically
+by the Autokey protocol.
+.Pp
+Ordinarily, cryptographic files are generated by the host that uses them,
+but it is possible for a trusted agent (TA) to generate these files
+for other hosts; however, in such cases files should always be encrypted.
+The subject name and trusted name default to the hostname
+of the host generating the files, but can be changed by command line options.
+It is convenient to designate the owner name and trusted name
+as the subject and issuer fields, respectively, of the certificate.
+The owner name is also used for the host and sign key files,
+while the trusted name is used for the identity files.
+seconds.
+seconds.
+s Trusted Hosts and Groups
+Each cryptographic configuration involves selection of a signature scheme
+and identification scheme, called a cryptotype,
+as explained in the
+.Sx Authentication Options
+section of
+.Xr ntp.conf 5 .
+The default cryptotype uses RSA encryption, MD5 message digest
+and TC identification.
+First, configure a NTP subnet including one or more low-stratum
+trusted hosts from which all other hosts derive synchronization
+directly or indirectly.
+Trusted hosts have trusted certificates;
+all other hosts have nontrusted certificates.
+These hosts will automatically and dynamically build authoritative
+certificate trails to one or more trusted hosts.
+A trusted group is the set of all hosts that have, directly or indirectly,
+a certificate trail ending at a trusted host.
+The trail is defined by static configuration file entries
+or dynamic means described on the
+.Sx Automatic NTP Configuration Options
+section of
+.Xr ntp.conf 5 .
+.Pp
+On each trusted host as root, change to the keys directory.
+To insure a fresh fileset, remove all
+.Cm ntpkey
+files.
+Then run
+.Nm
+.Fl T
+to generate keys and a trusted certificate.
+On all other hosts do the same, but leave off the
+.Fl T
+flag to generate keys and nontrusted certificates.
+When complete, start the NTP daemons beginning at the lowest stratum
+and working up the tree.
+It may take some time for Autokey to instantiate the certificate trails
+throughout the subnet, but setting up the environment is completely automatic.
+.Pp
+If it is necessary to use a different sign key or different digest/signature
+scheme than the default, run
+.Nm
+with the
+.Fl S Ar type
+option, where
+.Ar type
+is either
+.Cm RSA
+or
+.Cm DSA .
+The most often need to do this is when a DSA-signed certificate is used.
+If it is necessary to use a different certificate scheme than the default,
+run
+.Nm
+with the
+.Fl c Ar scheme
+option and selected
+.Ar scheme
+as needed.
+f
+.Nm
+is run again without these options, it generates a new certificate
+using the same scheme and sign key.
+.Pp
+After setting up the environment it is advisable to update certificates
+from time to time, if only to extend the validity interval.
+Simply run
+.Nm
+with the same flags as before to generate new certificates
+using existing keys.
+However, if the host or sign key is changed,
+.Xr ntpd @NTPD_MS@
+should be restarted.
+When
+.Xr ntpd @NTPD_MS@
+is restarted, it loads any new files and restarts the protocol.
+Other dependent hosts will continue as usual until signatures are refreshed,
+at which time the protocol is restarted.
+.Ss Identity Schemes
+As mentioned on the Autonomous Authentication page,
+the default TC identity scheme is vulnerable to a middleman attack.
+However, there are more secure identity schemes available,
+including PC, IFF, GQ and MV described on the
+.Qq Identification Schemes
+page
+(maybe available at
+.Li http://www.eecis.udel.edu/%7emills/keygen.html ) .
+These schemes are based on a TA, one or more trusted hosts
+and some number of nontrusted hosts.
+Trusted hosts prove identity using values provided by the TA,
+while the remaining hosts prove identity using values provided
+by a trusted host and certificate trails that end on that host.
+The name of a trusted host is also the name of its sugroup
+and also the subject and issuer name on its trusted certificate.
+The TA is not necessarily a trusted host in this sense, but often is.
+.Pp
+In some schemes there are separate keys for servers and clients.
+A server can also be a client of another server,
+but a client can never be a server for another client.
+In general, trusted hosts and nontrusted hosts that operate
+as both server and client have parameter files that contain
+both server and client keys.
+Hosts that operate
+only as clients have key files that contain only client keys.
+.Pp
+The PC scheme supports only one trusted host in the group.
+On trusted host alice run
+.Nm
+.Fl P
+.Fl p Ar password
+to generate the host key file
+.Pa ntpkey_RSAkey_ Ns Ar alice.filestamp
+and trusted private certificate file
+.Pa ntpkey_RSA-MD5_cert_ Ns Ar alice.filestamp .
+Copy both files to all group hosts;
+they replace the files which would be generated in other schemes.
+On each host bob install a soft link from the generic name
+.Pa ntpkey_host_ Ns Ar bob
+to the host key file and soft link
+.Pa ntpkey_cert_ Ns Ar bob
+to the private certificate file.
+Note the generic links are on bob, but point to files generated
+by trusted host alice.
+In this scheme it is not possible to refresh
+either the keys or certificates without copying them
+to all other hosts in the group.
+.Pp
+For the IFF scheme proceed as in the TC scheme to generate keys
+and certificates for all group hosts, then for every trusted host in the group,
+generate the IFF parameter file.
+On trusted host alice run
+.Nm
+.Fl T
+.Fl I
+.Fl p Ar password
+to produce her parameter file
+.Pa ntpkey_IFFpar_ Ns Ar alice.filestamp ,
+which includes both server and client keys.
+Copy this file to all group hosts that operate as both servers
+and clients and install a soft link from the generic
+.Pa ntpkey_iff_ Ns Ar alice
+to this file.
+If there are no hosts restricted to operate only as clients,
+there is nothing further to do.
+As the IFF scheme is independent
+of keys and certificates, these files can be refreshed as needed.
+.Pp
+If a rogue client has the parameter file, it could masquerade
+as a legitimate server and present a middleman threat.
+To eliminate this threat, the client keys can be extracted
+from the parameter file and distributed to all restricted clients.
+After generating the parameter file, on alice run
+.Nm
+.Fl e
+and pipe the output to a file or mail program.
+Copy or mail this file to all restricted clients.
+On these clients install a soft link from the generic
+.Pa ntpkey_iff_ Ns Ar alice
+to this file.
+To further protect the integrity of the keys,
+each file can be encrypted with a secret password.
+.Pp
+For the GQ scheme proceed as in the TC scheme to generate keys
+and certificates for all group hosts, then for every trusted host
+in the group, generate the IFF parameter file.
+On trusted host alice run
+.Nm
+.Fl T
+.Fl G
+.Fl p Ar password
+to produce her parameter file
+.Pa ntpkey_GQpar_ Ns Ar alice.filestamp ,
+which includes both server and client keys.
+Copy this file to all group hosts and install a soft link
+from the generic
+.Pa ntpkey_gq_ Ns Ar alice
+to this file.
+In addition, on each host bob install a soft link
+from generic
+.Pa ntpkey_gq_ Ns Ar bob
+to this file.
+As the GQ scheme updates the GQ parameters file and certificate
+at the same time, keys and certificates can be regenerated as needed.
+.Pp
+For the MV scheme, proceed as in the TC scheme to generate keys
+and certificates for all group hosts.
+For illustration assume trish is the TA, alice one of several trusted hosts
+and bob one of her clients.
+On TA trish run
+.Nm
+.Fl V Ar n
+.Fl p Ar password ,
+where
+.Ar n
+is the number of revokable keys (typically 5) to produce
+the parameter file
+.Pa ntpkeys_MVpar_ Ns Ar trish.filestamp
+and client key files
+.Pa ntpkeys_MVkeyd_ Ns Ar trish.filestamp
+where
+.Ar d
+is the key number (0 \&<
+.Ar d
+\&<
+.Ar n ) .
+Copy the parameter file to alice and install a soft link
+from the generic
+.Pa ntpkey_mv_ Ns Ar alice
+to this file.
+Copy one of the client key files to alice for later distribution
+to her clients.
+It doesn't matter which client key file goes to alice,
+since they all work the same way.
+Alice copies the client key file to all of her cliens.
+On client bob install a soft link from generic
+.Pa ntpkey_mvkey_ Ns Ar bob
+to the client key file.
+As the MV scheme is independent of keys and certificates,
+these files can be refreshed as needed.
+.Ss Command Line Options
+.Bl -tag -width indent
+.It Fl c Ar scheme
+Select certificate message digest/signature encryption scheme.
+The
+.Ar scheme
+can be one of the following:
+. Cm RSA-MD2 , RSA-MD5 , RSA-SHA , RSA-SHA1 , RSA-MDC2 , RSA-RIPEMD160 , DSA-SHA ,
+or
+.Cm DSA-SHA1 .
+Note that RSA schemes must be used with a RSA sign key and DSA
+schemes must be used with a DSA sign key.
+The default without this option is
+.Cm RSA-MD5 .
+.It Fl d
+Enable debugging.
+This option displays the cryptographic data produced in eye-friendly billboards.
+.It Fl e
+Write the IFF client keys to the standard output.
+This is intended for automatic key distribution by mail.
+.It Fl G
+Generate parameters and keys for the GQ identification scheme,
+obsoleting any that may exist.
+.It Fl g
+Generate keys for the GQ identification scheme
+using the existing GQ parameters.
+If the GQ parameters do not yet exist, create them first.
+.It Fl H
+Generate new host keys, obsoleting any that may exist.
+.It Fl I
+Generate parameters for the IFF identification scheme,
+obsoleting any that may exist.
+.It Fl i Ar name
+Set the suject name to
+.Ar name .
+This is used as the subject field in certificates
+and in the file name for host and sign keys.
+.It Fl M
+Generate MD5 keys, obsoleting any that may exist.
+.It Fl P
+Generate a private certificate.
+By default, the program generates public certificates.
+.It Fl p Ar password
+Encrypt generated files containing private data with
+.Ar password
+and the DES-CBC algorithm.
+.It Fl q
+Set the password for reading files to password.
+.It Fl S Oo Cm RSA | DSA Oc
+Generate a new sign key of the designated type,
+obsoleting any that may exist.
+By default, the program uses the host key as the sign key.
+.It Fl s Ar name
+Set the issuer name to
+.Ar name .
+This is used for the issuer field in certificates
+and in the file name for identity files.
+.It Fl T
+Generate a trusted certificate.
+By default, the program generates a non-trusted certificate.
+.It Fl V Ar nkeys
+Generate parameters and keys for the Mu-Varadharajan (MV) identification scheme.
+.El
+.Ss Random Seed File
+All cryptographically sound key generation schemes must have means
+to randomize the entropy seed used to initialize
+the internal pseudo-random number generator used
+by the library routines.
+The OpenSSL library uses a designated random seed file for this purpose.
+The file must be available when starting the NTP daemon and
+.Nm
+program.
+If a site supports OpenSSL or its companion OpenSSH,
+it is very likely that means to do this are already available.
+.Pp
+It is important to understand that entropy must be evolved
+for each generation, for otherwise the random number sequence
+would be predictable.
+Various means dependent on external events, such as keystroke intervals,
+can be used to do this and some systems have built-in entropy sources.
+Suitable means are described in the OpenSSL software documentation,
+but are outside the scope of this page.
+.Pp
+The entropy seed used by the OpenSSL library is contained in a file,
+usually called
+.Cm .rnd ,
+which must be available when starting the NTP daemon
+or the
+.Nm
+program.
+The NTP daemon will first look for the file
+using the path specified by the
+.Ic randfile
+subcommand of the
+.Ic crypto
+configuration command.
+If not specified in this way, or when starting the
+.Nm
+program,
+the OpenSSL library will look for the file using the path specified
+by the
+.Ev RANDFILE
+environment variable in the user home directory,
+whether root or some other user.
+If the
+.Ev RANDFILE
+environment variable is not present,
+the library will look for the
+.Cm .rnd
+file in the user home directory.
+If the file is not available or cannot be written,
+the daemon exits with a message to the system log and the program
+exits with a suitable error message.
+.Ss Cryptographic Data Files
+All other file formats begin with two lines.
+The first contains the file name, including the generated host name
+and filestamp.
+The second contains the datestamp in conventional Unix date format.
+Lines beginning with # are considered comments and ignored by the
+.Nm
+program and
+.Xr ntpd @NTPD_MS@
+daemon.
+Cryptographic values are encoded first using ASN.1 rules,
+then encrypted if necessary, and finally written PEM-encoded
+printable ASCII format preceded and followed by MIME content identifier lines.
+.Pp
+The format of the symmetric keys file is somewhat different
+than the other files in the interest of backward compatibility.
+Since DES-CBC is deprecated in NTPv4, the only key format of interest
+is MD5 alphanumeric strings.
+Following hte heard the keys are
+entered one per line in the format
+.D1 Ar keyno type key
+where
+.Ar keyno
+is a positive integer in the range 1-65,535,
+.Ar type
+is the string MD5 defining the key format and
+.Ar key
+is the key itself,
+which is a printable ASCII string 16 characters or less in length.
+Each character is chosen from the 93 printable characters
+in the range 0x21 through 0x7f excluding space and the
+.Ql #
+character.
+.Pp
+Note that the keys used by the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+programs
+are checked against passwords requested by the programs
+and entered by hand, so it is generally appropriate to specify these keys
+in human readable ASCII format.
+.Pp
+The
+.Nm
+program generates a MD5 symmetric keys file
+.Pa ntpkey_MD5key_ Ns Ar hostname.filestamp .
+Since the file contains private shared keys,
+it should be visible only to root and distributed by secure means
+to other subnet hosts.
+The NTP daemon loads the file
+.Pa ntp.keys ,
+so
+.Nm
+installs a soft link from this name to the generated file.
+Subsequently, similar soft links must be installed by manual
+or automated means on the other subnet hosts.
+While this file is not used with the Autokey Version 2 protocol,
+it is needed to authenticate some remote configuration commands
+used by the
+.Xr ntpq @NTPQ_MS@
+and
+.Xr ntpdc @NTPDC_MS@
+utilities.
.Sh "OPTIONS"
.Bl -tag
.It \-b " \fIimbits\fP, " \-\-imbits "=" \fIimbits\fP
If any of these are directories, then the file \fI.ntprc\fP
is searched for within those directories.
.Sh USAGE
+The
+.Fl p Ar password
+option specifies the write password and
+.Fl q Ar password
+option the read password for previously encrypted files.
+The
+.Nm
+program prompts for the password if it reads an encrypted file
+and the password is missing or incorrect.
+If an encrypted file is read successfully and
+no write password is specified, the read password is used
+as the write password by default.
.Sh "ENVIRONMENT"
See \fBOPTION PRESETS\fP for configuration environment variables.
.Sh "FILES"
Copyright (C) 1970-2013 The University of Delaware all rights reserved.
This program is released under the terms of the NTP license, <http://ntp.org/license>.
.Sh BUGS
-Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
+It can take quite a while to generate some cryptographic values,
+from one to several minutes with modern architectures
+such as UltraSPARC and up to tens of minutes to an hour
+with older architectures such as SPARC IPC.
+.Pp
+Please report bugs to http://bugs.ntp.org .Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
.Sh NOTES
+This document corresponds to version @VERSION@ of NTP.
+Portions of this document came from FreeBSD.
.Pp
This manual page was \fIAutoGen\fP-erated from the \fBntp-keygen\fP
option definitions.
projects / thirdparty / ntp.git / commitdiff
