doc: update chrony.texi

This commit is contained in:
Miroslav Lichvar 2015-01-23 11:20:31 +01:00
parent c8fe0fe992
commit 72f0f99ac3

View file

@ -430,15 +430,15 @@ install-info /usr/local/share/info/chrony.info /usr/share/info/dir
Now that the software is successfully installed, the next step is to
set up a configuration file. The default location of the file
is @file{@SYSCONFDIR@/chrony.conf}. Suppose you want to use public NTP
servers from the pool.ntp.org project as your time reference. A
is @file{@SYSCONFDIR@/chrony.conf}. Several examples of configuration with
comments are included in the examples directory. Suppose you want to use
public NTP servers from the pool.ntp.org project as your time reference. A
minimal useful configuration file could be
@example
server 0.pool.ntp.org iburst
server 1.pool.ntp.org iburst
server 2.pool.ntp.org iburst
pool pool.ntp.org iburst
makestep 10 3
rtcsync
@end example
Then, @code{chronyd} can be run.
@ -584,10 +584,10 @@ server baz.example.net
@end example
However, you will probably want to include some of the other directives
described later. The @code{driftfile} and @code{makestep} directives may be
particularly useful. Also, the @code{iburst} server option is useful to speed
up the initial synchronization. The smallest useful configuration file would
look something like
described later. The following directives may be particularly useful :
@code{driftfile}, @code{makestep}, @code{rtcsync}. Also, the @code{iburst}
server option is useful to speed up the initial synchronization. The smallest
useful configuration file would look something like
@example
server foo.example.net iburst
@ -595,6 +595,20 @@ server bar.example.net iburst
server baz.example.net iburst
driftfile @CHRONYVARDIR@/drift
makestep 10 3
rtcsync
@end example
When using a pool of NTP servers (one name is used for multiple servers which
may change over time), it's better to specify them with the @code{pool}
directive instead of multiple @code{server} directives in order to allow
@code{chronyd} to replace unreachable or bad servers automatically. The
configuration file could in this case look like
@example
pool pool.ntp.org iburst
driftfile @CHRONYVARDIR@/drift
makestep 10 3
rtcsync
@end example
@c }}}
@c {{{ S:Infrequent connection
@ -871,9 +885,9 @@ For the @file{@SYSCONFDIR@/chrony.conf} file, the following can be used as an
example.
@example
server 0.pool.ntp.org maxdelay 0.4 offline
server 1.pool.ntp.org maxdelay 0.4 offline
server 2.pool.ntp.org maxdelay 0.4 offline
server foo.example.net maxdelay 0.4 offline
server bar.example.net maxdelay 0.4 offline
server baz.example.net maxdelay 0.4 offline
logdir /var/log/chrony
log statistics measurements tracking
driftfile @CHRONYVARDIR@/drift
@ -1316,16 +1330,9 @@ bindaddress 192.168.1.1
to the configuration file.
This directive affects NTP (UDP port 123 by default) packets.
The @code{bindaddress} directive has been found to cause problems when used on
computers that need to pass NTP traffic over multiple network interfaces (e.g.
firewalls). It is, therefore, not particularly useful. Use of the
@code{allow} and @code{deny} directives together with a network firewall is
more likely to be successful.
For each of IPv4 and IPv6 protocols, only one @code{bindaddress}
directive can be specified.
For each of IPv4 and IPv6 protocols, only one @code{bindaddress} directive can
be specified. Therefore, it's not useful on computers which should serve NTP
on multiple network interfaces.
@c }}}
@c {{{ bindcmdaddress
@node bindcmdaddress directive
@ -4624,9 +4631,9 @@ For the current development from the developers' version control system see the
@code{Git} link on the web site.
@subsection Are there any packaged versions of chrony?
We are aware of packages for Arch, Debian, Fedora, Gentoo, Mandriva, Slackware,
Ubuntu, FreeBSD and NetBSD. We are not involved with how these are built or
distributed.
We are aware of packages for Arch, CentOS, Debian, Fedora, Gentoo, Mageia,
OpenSuse, Slackware, Ubuntu, FreeBSD and NetBSD. We are not involved with how
these are built or distributed.
@subsection Where is the home page?
It is currently at
@ -4711,9 +4718,12 @@ increasing intervals until it succeeds. The @code{online} command can be
issued from @code{chronyc} to try to resolve them immediately.
@subsection How can I make chronyd more secure?
If you don't need to serve time to NTP clients, you can add @code{port 0} to
the @file{chrony.conf} file to disable the NTP server/peer sockets and prevent
NTP requests from reaching @code{chronyd}.
If you don't need to serve time to NTP clients or peers, you can add
@code{port 0} to the @file{chrony.conf} file to completely disable the NTP
server functionality and prevent NTP requests from reaching @code{chronyd}.
Starting from version 2.0, the NTP server port is open only when client access
is allowed by the @code{allow} directive or command, an NTP peer is configured,
or the @code{broadcast} directive is used.
If you don't need to use @code{chronyc} remotely, you can add the following
directives to the configuration file to bind the command sockets to the