Assuming that you have found some servers, you need to set up a
configuration file to run chrony. The (compiled-in) default location
-for this file is @file{@SYSCONFDIR@/chrony.conf}. Assuming that your ntp
-servers are called @code{a.b.c} and @code{d.e.f}, your
-@file{chrony.conf} file could contain as a minimum
+for this file is @file{@SYSCONFDIR@/chrony.conf}. Assuming that your NTP
+servers are called @code{foo.example.net}, @code{bar.example.net} and
+@code{baz.example.net}, your @file{chrony.conf} file could contain as a minimum
@example
-server a.b.c
-server d.e.f
-server g.h.i
+server foo.example.net
+server bar.example.net
+server baz.example.net
@end example
However, you will probably want to include some of the other directives
look something like
@example
-server a.b.c iburst
-server d.e.f iburst
-server g.h.i iburst
+server foo.example.net iburst
+server bar.example.net iburst
+server baz.example.net iburst
driftfile @CHRONYVARDIR@/drift
makestep 10 3
@end example
This saves the program from continuously trying to poll the servers when
they are inaccessible.
-Again, assuming that your ntp servers are called @code{a.b.c} and
-@code{d.e.f}, your @file{chrony.conf} file would need to contain
-something like
+Again, assuming that your NTP servers are called @code{foo.example.net},
+@code{bar.example.net} and @code{baz.example.net}, your @file{chrony.conf} file
+would need to contain something like
@example
-server a.b.c
-server d.e.f
-server g.h.i
+server foo.example.net
+server bar.example.net
+server baz.example.net
@end example
However, your computer will keep trying to contact the servers to obtain
configuration file in the following way:
@example
-server a.b.c offline
-server d.e.f offline
-server g.h.i offline
+server foo.example.net offline
+server bar.example.net offline
+server baz.example.net offline
@end example
The @code{offline} keyword indicates that the servers start
The smallest useful configuration file would look something like
@example
-server a.b.c offline
-server d.e.f offline
-server g.h.i offline
+server foo.example.net offline
+server bar.example.net offline
+server baz.example.net offline
keyfile @SYSCONFDIR@/chrony.keys
generatecommandkey
driftfile @CHRONYVARDIR@/drift
Examples of use of the command are as follows:
@example
-allow foo.bar.com
+allow foo.example.net
allow 1.2
allow 3.4.5
allow 6.7.8/22
An example of use of the command is
@example
-initstepslew 30 foo.bar.com baz.quz.com
+initstepslew 30 foo.example.net bar.example.net
@end example
where 2 NTP servers are used to make the measurement. The @code{30}
follows:
@example
-accheck a.b.c
+accheck foo.example.net
accheck 1.2.3.4
accheck 2001:db8::1
@end example
An example of using this command is shown below.
@example
-add peer foo.bar.com minpoll 6 maxpoll 10 key 25
+add peer foo.example.net minpoll 6 maxpoll 10 key 25
@end example
@c }}}
@c {{{ add server
An example of using this command is shown below.
@example
-add server foo.bar.com minpoll 6 maxpoll 10 key 25
+add server foo.example.net minpoll 6 maxpoll 10 key 25
@end example
@c }}}
@c {{{ allow all
The syntax is illustrated in the following examples:
@example
-allow foo.bar.com
+allow foo.example.net
allow 1.2
allow 3.4.5
allow 6.7.8/22
Example of the three-argument form of the command is
@example
-burst 2/10 foo.bar.com
+burst 2/10 foo.example.net
@end example
@c }}}
@c {{{ clients
Examples of use are as follows:
@example
-cmdaccheck a.b.c
+cmdaccheck foo.example.net
cmdaccheck 1.2.3.4
cmdaccheck 2001:db8::1
@end example
The syntax is illustrated in the examples below.
@example
-delete foo.bar.com
+delete foo.example.net
delete 1.2.3.4
delete 2001:db8::1
@end example
The syntax is illustrated in the following examples:
@example
-deny foo.bar.com
+deny foo.example.net
deny 1.2
deny 3.4.5
deny 6.7.8/22
The following examples illustrate the syntax
@example
-maxdelay foo.bar.com 0.3
+maxdelay foo.example.net 0.3
maxdelay 1.2.3.4 0.0015
maxdelay 2001:db8::1 0.0015
@end example
The first example sets the maximum network delay allowed for a
-measurement to the host @code{foo.bar.com} to 0.3 seconds. The second
+measurement to the host @code{foo.example.net} to 0.3 seconds. The second
and third examples set the maximum network delay for a measurement to
the host with IPv4 address @code{1.2.3.4} and the host with IPv6 address
@code{2001:db8::1} to 1.5 milliseconds.
The following examples illustrate the syntax
@example
-maxdelaydevratio foo.bar.com 0.1
+maxdelaydevratio foo.example.net 0.1
maxdelaydevratio 1.2.3.4 1.0
maxdelaydevratio 2001:db8::1 100.0
@end example
The following examples illustrate the syntax
@example
-maxdelayratio foo.bar.com 1.5
+maxdelayratio foo.example.net 1.5
maxdelayratio 1.2.3.4 2.0
maxdelayratio 2001:db8::1 2.0
@end example
The first example sets the maximum network delay for a measurement to
-the host @code{foo.bar.com} to be 1.5 times the minimum delay found
+the host @code{foo.example.net} to be 1.5 times the minimum delay found
amongst the previous measurements that have been retained. The second
and third examples set the maximum network delay for a measurement to
the host with IPv4 address @code{1.2.3.4} and the host with IPv6
An example is
@example
-maxpoll foo.bar.com 10
+maxpoll foo.example.net 10
@end example
-which sets the maximum polling interval for the host @code{foo.bar.com}
+which sets the maximum polling interval for the host @code{foo.example.net}
to 1024 seconds.
Note that the new maximum polling interval only takes effect after the
An example is
@example
-minpoll foo.bar.com 5
+minpoll foo.example.net 5
@end example
-which sets the minimum polling interval for the host @code{foo.bar.com}
+which sets the minimum polling interval for the host @code{foo.example.net}
to 32 seconds.
Note that the new minimum polling interval only takes effect after the
An example is
@example
-minpoll foo.bar.com 5
+minpoll foo.example.net 5
@end example
-which sets the minimum stratum for the host @code{foo.bar.com}
+which sets the minimum stratum for the host @code{foo.example.net}
to 5.
Note that the new minimum stratum only takes effect after the
offline
offline 255.255.255.0/1.2.3.0
offline 2001:db8:789a::/48
-offline foo.bar.com
+offline foo.example.net
@end example
The second form means that the @code{offline} command is to be applied
An example is
@example
-polltarget foo.bar.com 12
+polltarget foo.example.net 12
@end example
-which sets the poll target for the host @code{foo.bar.com}
+which sets the poll target for the host @code{foo.example.net}
to 12.
@c }}}
@c {{{ quit
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* GPS0 0 4 377 11 -479ns[ -621ns] +/- 134ns
-^? a.b.c 2 6 377 23 -923us[ -924us] +/- 43ms
-^+ d.e.f 1 6 377 21 -2629us[-2619us] +/- 86ms
+^? foo.example.net 2 6 377 23 -923us[ -924us] +/- 43ms
+^+ bar.example.net 1 6 377 21 -2629us[-2619us] +/- 86ms
@end group
@end example
performance. An example of the output is shown below.
@example
-Reference ID : 1.2.3.4 (a.b.c)
+Reference ID : 1.2.3.4 (foo.example.net)
Stratum : 3
Ref time (UTC) : Fri Feb 3 15:00:29 2012
System time : 0.000001501 seconds slow of NTP time
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. @code{a.b.c} is a stratum-2 and is synchronised from a stratum-1).
+(i.e. @code{foo.example.net} is a stratum-2 and is synchronised from a stratum-1).
@item Ref time
This is the time (UTC) at which the last measurement from the reference
projects / thirdparty / chrony.git / commitdiff
