1 .\" $OpenBSD: src/usr.sbin/ntpd/ntpd.8,v 1.13 2004/12/10 03:54:18 jaredy Exp $
3 .\" Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
5 .\" Permission to use, copy, modify, and distribute this software for any
6 .\" purpose with or without fee is hereby granted, provided that the above
7 .\" copyright notice and this permission notice appear in all copies.
9 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 .\" WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN
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22 .Nd "Network Time Protocol daemon"
32 daemon synchronizes the local clock to one or more remote NTP servers,
33 and can also act as an NTP server itself,
34 redistributing the local time.
35 It implements the Simple Network Time Protocol version 4,
36 as described in RFC 2030,
37 and the Network Time Protocol version 3,
38 as described in RFC 1305.
43 system call to correct the local system time without causing time jumps.
44 Adjustments larger than 128ms are logged using
46 The threshold value is chosen to avoid having local clock drift
57 is usually started at boot time, and can be enabled by
58 setting the following in
59 .Pa /etc/rc.conf.local :
67 for more information on the boot process
72 starts up, it reads settings from a configuration file,
76 The options are as follows:
77 .Bl -tag -width "-f fileXXX"
80 If this option is specified,
82 will run in the foreground and log to
87 as the configuration file,
88 instead of the default
91 Do not set the time immediately at startup.
94 Set the time immediately at startup if the local clock is off by more
96 Allows for a large time correction,
97 eliminating the need to run
103 option is added unconditionally in
105 Make sure to specify the
111 .Xr rc.conf.local 8 )
112 if this behaviour is not desired.
115 .Bl -tag -width "/etc/ntpd.confXXX" -compact
116 .It Pa /etc/ntpd.conf
131 .%T "Network Time Protocol (Version 3)"
136 .%T "Simple Network Time Protocol (SNTP) Version 4"
142 program first appeared in