MirBSD manpage: ntpd(8)

NTPD(8)                  BSD System Manager's Manual                   NTPD(8)


     ntpd - Network Time Protocol daemon


     ntpd [-dSst] [-f file]


     The ntpd daemon synchronizes the local clock to one or more remote NTP
     servers, and can also act as an NTP server itself, redistributing the lo-
     cal time. It implements the Simple Network Time Protocol version 4, as
     described in RFC 2030, and the Network Time Protocol version 3, as
     described in RFC 1305.

     ntpd uses the adjtime(2) system call to correct the local system time
     without causing time jumps. Adjustments are logged using syslog(3).

     Leap seconds are accounted correctly on MirBSD using the libc
     tai_leaps(3) facility. However, NTP will not survive the year 2038.

     ntpd is usually started at boot time, and can be enabled by setting the
     following in /etc/rc.conf.local:


     See rc(8) and rc.conf(8) for more information on the boot process and
     enabling daemons.

     When ntpd starts up, it reads settings from a configuration file, typi-
     cally ntpd.conf(5).

     The options are as follows:

     -d          Do not daemonize. If this option is specified, ntpd will run
                 in the foreground and log to stderr.

     -f file     Use file as the configuration file, instead of the default

     -S          Do not set the time immediately at startup. This is the de-

                 This option is deprecated.

     -s          Set the time immediately at startup if the local clock is off
                 by more than 180 seconds. Allows for a large time correction,
                 eliminating the need to run rdate(8) before starting ntpd.

                 This option is deprecated.

     -t          Trace information about the peer(s) used for adjusting. Use
                 several times for more information, unless running with -d.


     /etc/ntpd.conf     default ntpd configuration file

     ntpd throws away all previously received replies from all peers and sends
     out two queries quickly to re-sync when it receives SIGUSR1.


     date(1), adjtime(2), ntpd.conf(5), rc(8), rc.conf(8), rdate(8),
     taitime(3), timed(8)

     Network Time Protocol (Version 3), RFC 1305, March 1992.

     Simple Network Time Protocol (SNTP) Version 4, RFC 2030, October 1996.


     The ntpd program first appeared in OpenBSD 3.6.

     Support for correct leap second handling was added in MirBSD #8. Trace
     and serverloop support was added in MirBSD #10. The -s and -S options
     were removed and SIGUSR1 handling was added in MirBSD #11.

MirBSD #10-current            September 4, 2020                              1

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