1 1.6 fredb # $NetBSD: ntp.conf,v 1.6 2003/12/07 16:01:00 fredb Exp $ 2 1.1 fair # 3 1.1 fair # NetBSD default Network Time Protocol (NTP) configuration file 4 1.2 simonb # for ntpd 5 1.1 fair 6 1.1 fair # Process ID file, so that the daemon can be signalled from scripts 7 1.1 fair 8 1.3 lukem pidfile /var/run/ntpd.pid 9 1.1 fair 10 1.2 simonb # The correction calculated by ntpd(8) for the local system clock's 11 1.1 fair # drift is stored here 12 1.1 fair 13 1.3 lukem driftfile /var/db/ntp.drift 14 1.1 fair 15 1.1 fair # suppress the syslog(3) message for each peer synchronization change 16 1.1 fair 17 1.3 lukem logconfig -syncstatus 18 1.5 fredb 19 1.5 fredb # This will help minimize disruptions due to network congestion. Don't 20 1.5 fredb # do this if you configure only one server! 21 1.5 fredb 22 1.5 fredb tos minsane 2 23 1.1 fair 24 1.1 fair # Hereafter should be "server" or "peer" statements to configure 25 1.1 fair # other hosts to exchange NTP packets with. Peers should be selected 26 1.1 fair # in such a way that the network path to them is symmetric (that is, 27 1.1 fair # the series of links and routers used to get to the peer is the same 28 1.1 fair # one that the peer uses to get back. NTP assumes such symmetry 29 1.1 fair # in its network delay calculation. NTP will apply an incorrect 30 1.1 fair # adjustment to timestamps received from the peer if the path is not 31 1.1 fair # symmetric. This can result in clock skew (your system clock being 32 1.1 fair # maintained consistently wrong by a certain amount). 33 1.1 fair # 34 1.1 fair # The best way to select symmetric peers is to make sure that the 35 1.1 fair # network path to them is as short as possible (this reduces the 36 1.1 fair # chance that there is more than one network path between you and 37 1.1 fair # your peer). You can measure these distances with the traceroute(8) 38 1.1 fair # program. The best place to start looking for NTP peers for your 39 1.1 fair # system is within your own network, or at your Internet Service 40 1.1 fair # Provider (ISP). 41 1.1 fair # 42 1.1 fair # Ideally, you should select at least three other systems to talk 43 1.1 fair # NTP with, for an "what I tell you three times is true" effect. 44 1.1 fair # 45 1.1 fair 46 1.3 lukem #peer an.ntp.peer.goes.here 47 1.3 lukem #server an.ntp.server.goes.here 48 1.4 agc 49 1.6 fredb # Public servers from the pool.ntp.org project. Volunteer's servers 50 1.6 fredb # are dynamically assigned to the CNAMES below via DNS round-robin. 51 1.6 fredb # The pool.ntp.org project needs more volunteers! The only criteria to 52 1.6 fredb # join are a nailed-up connection and a static IP address. For details, 53 1.6 fredb # see the web page: 54 1.6 fredb # 55 1.4 agc # http://www.pool.ntp.org/ 56 1.6 fredb # 57 1.6 fredb 58 1.6 fredb # The country codes can help you find servers that are net-wise close. 59 1.6 fredb # As explained above, closer is better... 60 1.4 agc 61 1.6 fredb # Northern U.S.A 62 1.6 fredb #server ca.pool.ntp.org 63 1.6 fredb #server us.pool.ntp.org 64 1.6 fredb #server us.pool.ntp.org 65 1.6 fredb 66 1.6 fredb # Northern Europe 67 1.6 fredb #server de.pool.ntp.org 68 1.6 fredb #server de.pool.ntp.org 69 1.6 fredb #server dk.pool.ntp.org 70 1.6 fredb 71 1.6 fredb # Depending on the vagaries of DNS can occasionally pull in the same 72 1.6 fredb # server twice. The following CNAMES are guaranteed to be disjoint, at 73 1.6 fredb # least over some short interval. 74 1.6 fredb 75 1.6 fredb server 0.pool.ntp.org 76 1.6 fredb server 1.pool.ntp.org 77 1.6 fredb server 2.pool.ntp.org 78