Provided by: openntpd_3.9p1+debian-9_i386
ntpd - "Network Time Protocol daemon"
ntpd [-dSs] [-f conffile] [-p pidfile]
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) with LOG_INFO priority. 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,
When ntpd receives a SIGUSR1 signal, it writes its peer status to
The options are as follows:
-d Do not daemonize. If this option is specified, ntpd will run in
the foreground and log to stderr.
Use conffile as the configuration file, instead of the default
Specify the name and path of the file used to record the ntpd
-S Do not set the time immediately at startup. This is the
-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 .
default ntpd configuration file
Contains the process ID of the ntpd listening for connections.
date(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.
The ntpd program first appeared in OpenBSD 3.6 .
July 9, 2004 NTPD(8)