NTPD(8)NTPD(8)NAMEntpd - "Network Time Protocol daemon"
SYNOPSISntpd [-dSs] [-f file]
DESCRIPTION
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
local 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 larger than 128ms are logged
using syslog(3). The threshold value is chosen to avoid having local
clock drift thrash the log files. Should ntpd be started with the -d
option, all calls to adjtime(2) will be logged.
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
/etc/ntpd.conf.
-S Do not set the time immediately at startup. This is the
default.
-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 .
FILES
/etc/ntpd.conf
default ntpd configuration file
SEE ALSOdate(1), adjtime(2), ntpd.conf(5), rdate(8), timed(8)
, Network Time Protocol (Version 3), March 1992.
, Simple Network Time Protocol (SNTP) Version 4, October 1996.
HISTORY
The ntpd program first appeared in OpenBSD 3.6 .
July 9, 2004 NTPD(8)
