ntp.conf revision 1.8 1 1.8 fredb # $NetBSD: ntp.conf,v 1.8 2003/12/07 16:11:58 fredb Exp $
2 1.1 fair #
3 1.7 fredb # NetBSD default Network Time Protocol (NTP) configuration file for ntpd
4 1.8 fredb
5 1.8 fredb # This file is intended to be both a usable default, and a Quick-Start
6 1.8 fredb # Guide. The directives and options listed here are not at all complete.
7 1.8 fredb # A great deal of additional documention, including links to FAQS and
8 1.8 fredb # other guides, may be found on the official NTP web site, in particular
9 1.8 fredb #
10 1.8 fredb # http://www.ntp.org/documentation.html
11 1.8 fredb #
12 1.1 fair
13 1.1 fair # Process ID file, so that the daemon can be signalled from scripts
14 1.1 fair
15 1.3 lukem pidfile /var/run/ntpd.pid
16 1.1 fair
17 1.2 simonb # The correction calculated by ntpd(8) for the local system clock's
18 1.7 fredb # drift is stored here.
19 1.1 fair
20 1.3 lukem driftfile /var/db/ntp.drift
21 1.1 fair
22 1.7 fredb # Suppress the syslog(3) message for each peer synchronization change.
23 1.1 fair
24 1.3 lukem logconfig -syncstatus
25 1.5 fredb
26 1.5 fredb # This will help minimize disruptions due to network congestion. Don't
27 1.5 fredb # do this if you configure only one server!
28 1.5 fredb
29 1.5 fredb tos minsane 2
30 1.1 fair
31 1.7 fredb # Hereafter should be "server" or "peer" statements to configure other
32 1.7 fredb # hosts to exchange NTP packets with. Peers should be selected in such
33 1.7 fredb # a way that the network path to them is symmetric (that is, the series
34 1.7 fredb # of links and routers used to get to the peer is the same one that the
35 1.7 fredb # peer uses to get back. NTP assumes such symmetry in its network delay
36 1.7 fredb # calculation. NTP will apply an incorrect adjustment to timestamps
37 1.7 fredb # received from the peer if the path is not symmetric. This can result
38 1.7 fredb # in clock skew (your system clock being maintained consistently wrong
39 1.7 fredb # by a certain amount).
40 1.7 fredb #
41 1.1 fair # The best way to select symmetric peers is to make sure that the
42 1.7 fredb # network path to them is as short as possible (this reduces the chance
43 1.7 fredb # that there is more than one network path between you and your peer).
44 1.7 fredb # You can measure these distances with the traceroute(8) program. The
45 1.7 fredb # best place to start looking for NTP peers for your system is within
46 1.7 fredb # your own network, or at your Internet Service Provider (ISP).
47 1.1 fair #
48 1.7 fredb # Ideally, you should select at least three other systems to talk NTP
49 1.7 fredb # with, for an "what I tell you three times is true" effect.
50 1.1 fair #
51 1.1 fair
52 1.3 lukem #peer an.ntp.peer.goes.here
53 1.3 lukem #server an.ntp.server.goes.here
54 1.4 agc
55 1.6 fredb # Public servers from the pool.ntp.org project. Volunteer's servers
56 1.6 fredb # are dynamically assigned to the CNAMES below via DNS round-robin.
57 1.6 fredb # The pool.ntp.org project needs more volunteers! The only criteria to
58 1.6 fredb # join are a nailed-up connection and a static IP address. For details,
59 1.6 fredb # see the web page:
60 1.6 fredb #
61 1.4 agc # http://www.pool.ntp.org/
62 1.6 fredb #
63 1.6 fredb
64 1.6 fredb # The country codes can help you find servers that are net-wise close.
65 1.6 fredb # As explained above, closer is better...
66 1.4 agc
67 1.6 fredb # Northern U.S.A
68 1.6 fredb #server ca.pool.ntp.org
69 1.6 fredb #server us.pool.ntp.org
70 1.6 fredb #server us.pool.ntp.org
71 1.6 fredb
72 1.6 fredb # Northern Europe
73 1.6 fredb #server de.pool.ntp.org
74 1.6 fredb #server de.pool.ntp.org
75 1.6 fredb #server dk.pool.ntp.org
76 1.6 fredb
77 1.6 fredb # Depending on the vagaries of DNS can occasionally pull in the same
78 1.6 fredb # server twice. The following CNAMES are guaranteed to be disjoint, at
79 1.6 fredb # least over some short interval.
80 1.6 fredb
81 1.6 fredb server 0.pool.ntp.org
82 1.6 fredb server 1.pool.ntp.org
83 1.6 fredb server 2.pool.ntp.org
84