An example of the use of the directive is:
+
----
-initstepslew 30 foo.example.net bar.example.net baz.example.net
+initstepslew 30 ntp1.example.net ntp2.example.net ntp3.example.net
----
+
where 3 NTP servers are used to make the measurement. The _30_ indicates that
An example is:
+
----
-ntstrustedcerts /etc/pki/nts/foo.crt
-ntstrustedcerts 1 /etc/pki/nts/bar.crt
-ntstrustedcerts 1 /etc/pki/nts/baz.crt
-ntstrustedcerts 2 /etc/pki/nts/qux.crt
+ntstrustedcerts /etc/pki/nts/ca1.example.net.crt
+ntstrustedcerts 1 /etc/pki/nts/ca2.example.net.crt
+ntstrustedcerts 1 /etc/pki/nts/ca3.example.net.crt
+ntstrustedcerts 2 /etc/pki/nts/ntp2.example.net.crt
----
[[nosystemcert]]*nosystemcert*::
As an example, the following configuration using the default *mix* mode:
+
----
-server foo.example.net nts
-server bar.example.net nts
-server baz.example.net
+server ntp1.example.net nts
+server ntp2.example.net nts
+server ntp3.example.net
refclock SOCK /var/run/chrony.ttyS0.sock
----
+
+
----
authselectmode ignore
-server foo.example.net nts require trust
-server bar.example.net nts require trust
-server baz.example.net
+server ntp1.example.net nts require trust
+server ntp2.example.net nts require trust
+server ntp3.example.net
refclock /var/run/chrony.ttyS0.sock require trust
----
An example of client configuration is:
+
----
-server foo.example.net minpoll 0 maxpoll 0 xleave port 319 extfield F324
+server ntp1.example.net minpoll 0 maxpoll 0 xleave port 319 extfield F324
hwtimestamp * rxfilter ptp
ptpport 319
----
facilities.
* Use public servers from the https://www.pool.ntp.org/[pool.ntp.org] project.
-Assuming that your NTP servers are called _foo.example.net_, _bar.example.net_
-and _baz.example.net_, your _chrony.conf_ file could contain as a minimum:
+Assuming that your NTP servers are called _ntp1.example.net_, _ntp2.example.net_
+and _ntp3.example.net_, your _chrony.conf_ file could contain as a minimum:
----
-server foo.example.net
-server bar.example.net
-server baz.example.net
+server ntp1.example.net
+server ntp2.example.net
+server ntp3.example.net
----
However, you will probably want to include some of the other directives. The
like:
----
-server foo.example.net iburst
-server bar.example.net iburst
-server baz.example.net iburst
+server ntp1.example.net iburst
+server ntp2.example.net iburst
+server ntp3.example.net iburst
driftfile @CHRONYVARDIR@/drift
makestep 1.0 3
rtcsync
file could look like:
----
-server foo.example.net iburst nts
-server bar.example.net iburst nts
-server baz.example.net iburst nts
+server ntp1.example.net iburst nts
+server ntp2.example.net iburst nts
+server ntp3.example.net iburst nts
driftfile @CHRONYVARDIR@/drift
makestep 1.0 3
rtcsync
down. This saves the program from continuously trying to poll the servers when
they are inaccessible.
-Again, assuming that your NTP servers are called _foo.example.net_,
-_bar.example.net_ and _baz.example.net_, your _chrony.conf_ file would now
+Again, assuming that your NTP servers are called _ntp1.example.net_,
+_ntp2.example.net_ and _ntp3.example.net_, your _chrony.conf_ file would now
contain:
----
-server foo.example.net offline
-server bar.example.net offline
-server baz.example.net offline
+server ntp1.example.net offline
+server ntp2.example.net offline
+server ntp3.example.net offline
driftfile @CHRONYVARDIR@/drift
makestep 1.0 3
rtcsync
For the _chrony.conf_ file, the following can be used as an example.
----
-server foo.example.net maxdelay 0.4 offline
-server bar.example.net maxdelay 0.4 offline
-server baz.example.net maxdelay 0.4 offline
+server ntp1.example.net maxdelay 0.4 offline
+server ntp2.example.net maxdelay 0.4 offline
+server ntp3.example.net maxdelay 0.4 offline
logdir /var/log/chrony
log statistics measurements tracking
driftfile @CHRONYVARDIR@/drift
The configuration file could look like:
----
-server foo.example.net iburst
-server bar.example.net iburst
-server baz.example.net iburst
-server qux.example.net iburst
+server ntp1.example.net iburst
+server ntp2.example.net iburst
+server ntp3.example.net iburst
+server ntp4.example.net iburst
makestep 1.0 3
rtcsync
allow
performance. An example of the output is shown below.
+
----
-Reference ID : CB00710F (foo.example.net)
+Reference ID : CB00710F (ntp1.example.net)
Stratum : 3
Ref time (UTC) : Fri Jan 27 09:49:17 2017
System time : 0.000006523 seconds slow of NTP time
*Stratum*:::
The stratum indicates how many hops away from a computer with an attached
reference clock we are. Such a computer is a stratum-1 computer, so the
-computer in the example is two hops away (i.e. _foo.example.net_ is a
+computer in the example is two hops away (i.e. _ntp1.example.net_ is a
stratum-2 and is synchronised from a stratum-1).
*Ref time*:::
This is the time (UTC) at which the last measurement from the reference
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* GPS0 0 4 377 11 -479ns[ -621ns] +/- 134ns
-^? foo.example.net 2 6 377 23 -923us[ -924us] +/- 43ms
-^+ bar.example.net 1 6 377 21 -2629us[-2619us] +/- 86ms
+^? ntp1.example.net 2 6 377 23 -923us[ -924us] +/- 43ms
+^+ ntp2.example.net 1 6 377 21 -2629us[-2619us] +/- 86ms
----
+
The columns are as follows:
----
Name/IP Address NP NR Span Frequency Freq Skew Offset Std Dev
===============================================================================
-foo.example.net 11 5 46m -0.001 0.045 1us 25us
+ntp1.example.net 11 5 46m -0.001 0.045 1us 25us
----
+
The columns are as follows:
----
S Name/IP Address Auth COpts EOpts Last Score Interval Leap
=======================================================================
-D foo.example.net Y ----- --TR- 4 1.0 -61ms +62ms N
-* bar.example.net N ----- ----- 0 1.0 -6846us +7305us N
-+ baz.example.net N ----- ----- 10 1.0 -7381us +7355us N
+D ntp1.example.net Y ----- --TR- 4 1.0 -61ms +62ms N
+* ntp2.example.net N ----- ----- 0 1.0 -6846us +7305us N
++ ntp3.example.net N ----- ----- 10 1.0 -7381us +7355us N
----
+
The columns are as follows:
----
Name/IP address Mode KeyID Type KLen Last Atmp NAK Cook CLen
=========================================================================
-foo.example.net NTS 1 15 256 135m 0 0 8 100
-bar.example.net SK 30 13 128 - 0 0 0 0
-baz.example.net - 0 0 0 - 0 0 0 0
+ntp1.example.net NTS 1 15 256 135m 0 0 8 100
+ntp2.example.net SK 30 13 128 - 0 0 0 0
+ntp3.example.net - 0 0 0 - 0 0 0 0
----
+
The columns are as follows:
An example of using this command is shown below.
+
----
-add peer foo.example.net minpoll 6 maxpoll 10 key 25
+add peer ntp1.example.net minpoll 6 maxpoll 10 key 25
----
[[add_pool]]*add pool* _name_ [_option_]...::
An example of using this command is shown below:
+
----
-add pool foo.example.net maxsources 3 iburst
+add pool ntp1.example.net maxsources 3 iburst
----
[[add_server]]*add server* _name_ [_option_]...::
An example of using this command is shown below:
+
----
-add server foo.example.net minpoll 6 maxpoll 10 key 25
+add server ntp1.example.net minpoll 6 maxpoll 10 key 25
----
[[delete]]*delete* _address_::
Example of the three-argument form of the command is:
+
----
-burst 2/10 foo.example.net
+burst 2/10 ntp1.example.net
----
[[maxdelay]]*maxdelay* _address_ _delay_::
offline
offline 255.255.255.0/1.2.3.0
offline 2001:db8:789a::/48
-offline foo.example.net
+offline ntp1.example.net
----
+
The second form means that the *offline* command is to be applied to any source
Examples of use, showing a named host and a numeric IP address, are as follows:
+
----
-accheck foo.example.net
+accheck ntp1.example.net
accheck 1.2.3.4
accheck 2001:db8::1
----
Hostname NTP Drop Int IntL Last Cmd Drop Int Last
===============================================================================
localhost 2 0 2 - 133 15 0 -1 7
-foo.example.net 12 0 6 - 23 0 0 - -
+ntp1.example.net 12 0 6 - 23 0 0 - -
----
+
Each row shows the data for a single host. Only hosts that have passed the host
Examples of use are as follows:
+
----
-cmdaccheck foo.example.net
+cmdaccheck ntp1.example.net
cmdaccheck 1.2.3.4
cmdaccheck 2001:db8::1
----
be
----
-server foo.example.net iburst nts maxdelay 0.1
-server bar.example.net iburst nts maxdelay 0.2
-server baz.example.net iburst nts maxdelay 0.05
-server qux.example.net iburst nts maxdelay 0.1
-server quux.example.net iburst nts maxdelay 0.1
+server ntp1.example.net iburst nts maxdelay 0.1
+server ntp2.example.net iburst nts maxdelay 0.2
+server ntp3.example.net iburst nts maxdelay 0.05
+server ntp4.example.net iburst nts maxdelay 0.1
+server ntp5.example.net iburst nts maxdelay 0.1
minsources 3
maxchange 100 0 0
makestep 0.001 1
allowed to poll frequently could be
----
-server foo.example.net minpoll 4 maxpoll 6 polltarget 16
+server ntp.example.net minpoll 4 maxpoll 6 polltarget 16
----
An example using shorter polling intervals with a server located in the same
----
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
-^* foo.example.net 2 6 377 34 +484us[ -157us] +/- 30ms
-^- bar.example.net 2 6 377 34 +33ms[ +32ms] +/- 47ms
-^+ baz.example.net 3 6 377 35 -1397us[-2033us] +/- 60ms
+^* ntp1.example.net 2 6 377 34 +484us[ -157us] +/- 30ms
+^- ntp2.example.net 2 6 377 34 +33ms[ +32ms] +/- 47ms
+^+ ntp3.example.net 3 6 377 35 -1397us[-2033us] +/- 60ms
----
=== Are NTP servers specified with the `offline` option?
# chronyc -N authdata
Name/IP address Mode KeyID Type KLen Last Atmp NAK Cook CLen
=========================================================================
-foo.example.net NTS 1 15 256 33m 0 0 8 100
-bar.example.net NTS 1 15 256 33m 0 0 8 100
-baz.example.net NTS 1 15 256 33m 0 0 8 100
+ntp1.example.net NTS 1 15 256 33m 0 0 8 100
+ntp2.example.net NTS 1 15 256 33m 0 0 8 100
+ntp3.example.net NTS 1 15 256 33m 0 0 8 100
----
The KeyID, Type, and KLen columns should have non-zero values. If they are
==============================================================================
PPS0 0 0 0 +0.000 2000.000 +0ns 4000ms
NMEA 58 30 231 -96.494 38.406 +504ms 6080us
-foo.example.net 7 3 200 -2.991 16.141 -107us 492us
+ntp1.example.net 7 3 200 -2.991 16.141 -107us 492us
----
the offset of the NMEA source would need to be increased by about 0.504
# you can access at http://support.ntp.org/bin/view/Servers/WebHome or
# you can use servers from the pool.ntp.org project.
-! server foo.example.net iburst
-! server bar.example.net iburst
-! server baz.example.net iburst
+! server ntp1.example.net iburst
+! server ntp2.example.net iburst
+! server ntp3.example.net iburst
! pool pool.ntp.org iburst
# and edit the following lines to specify the locations of the certificate and
# key.
-! ntsservercert /etc/.../foo.example.net.crt
-! ntsserverkey /etc/.../foo.example.net.key
+! ntsservercert /etc/.../nts-server.crt
+! ntsserverkey /etc/.../nts-server.key
# chronyd can save the measurement history for the servers to files when
# it exits. This is useful in 2 situations:
# several people, you need to set up a mailing list or sendmail alias
# for them and use the address of that.)
-! mailonchange wibble@foo.example.net 0.5
+! mailonchange wibble@example.net 0.5
#######################################################################
### COMMAND ACCESS