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      1 # $NetBSD: ntp.conf,v 1.23 2021/10/28 07:24:40 kim Exp $
      2 #
      3 # NetBSD default Network Time Protocol (NTP) configuration file for ntpd
      4 
      5 # This file is intended to be both a usable default, and a Quick-Start
      6 # Guide. The directives and options listed here are not at all complete.
      7 # A great deal of additional documentation, including links to FAQS and
      8 # other guides, may be found on the official NTP web site, in particular
      9 #
     10 #	http://www.ntp.org/documentation.html
     11 
     12 # Process ID file, so that the daemon can be signalled from scripts
     13 
     14 pidfile /var/run/ntpd.pid
     15 
     16 # Don't give up even if the reference time is hugely different. This can
     17 # happen if the system was suspended and resumed.
     18 
     19 #tinker panic 0
     20 
     21 # The correction calculated by ntpd(8) for the local system clock's
     22 # drift is stored here.
     23 
     24 driftfile /var/db/ntp.drift
     25 
     26 # Suppress the syslog(3) message for each peer synchronization change.
     27 
     28 logconfig -syncstatus
     29 
     30 # Refuse to set the local clock if there are too few good peers or servers.
     31 # This may help minimize disruptions due to network congestion. Don't
     32 # do this if you configure only one server!
     33 
     34 tos minsane 2
     35 
     36 # Set the target and limit for adding servers configured via pool statements
     37 # or discovered dynamically via mechanisms such as broadcast and manycast.
     38 # Ntpd automatically adds maxclock-1 servers from configured pools, and may
     39 # add as many as maxclock*2 if necessary to ensure that at least minclock
     40 # servers are providing good consistent time.
     41 
     42 tos minclock 3 maxclock 6
     43 
     44 # Set the number of tries to register with mdns. 0 means never
     45 
     46 mdnstries 0
     47 
     48 # New ntpd disables the ntpdc protocol by default, to re-enable uncomment
     49 # the following line
     50 
     51 #enable mode7
     52 
     53 # Allow hasty ntpdate clients to avoid rate limiting / kod responses.
     54 # The default is 2 seconds between packets from the client.
     55 
     56 #discard minimum 1
     57 
     58 # Access control restrictions.
     59 # See /usr/share/doc/html/ntp/accopt.html for syntax.
     60 # See <http://support.ntp.org/bin/view/Support/AccessRestrictions> for advice.
     61 # Last match wins.
     62 #
     63 # Some of the more common keywords are:
     64 #   ignore      Deny packets of all kinds.
     65 #   limited     Deny time service if the packet violates the rate limits
     66 #               established by the discard command. Does not affect ntpq or
     67 #               ntpdc queries.
     68 #   kod         Send "kiss-o'-death" packets if clients exceed rate limits.
     69 #               No effect without the limited flag.
     70 #   nomodify    Deny attempts to modify the state of the server via ntpq or
     71 #               ntpdc queries.
     72 #   noquery     Deny all ntpq and ntpdc queries.  Does not affect time
     73 #               synchronisation.
     74 #   nopeer      Prevent establishing new peer associations.
     75 #               Does not affect peers configured using "peer" lines.
     76 #               Does not affect client/server time synchronisation.
     77 #   noserve     Deny all time synchronisation.  Does not affect ntpq or
     78 #               ntpdc queries.
     79 #   notrap      Deny the trap subset of the ntpdc control message protocol.
     80 #   notrust     Deny packets that are not cryptographically authenticated.
     81 #
     82 # By default, allow client/server time exchange without prior
     83 # arrangement, but deny configuration changes, queries, and peer
     84 # associations that were not explicitly configured.
     85 
     86 restrict default limited kod nomodify notrap nopeer noquery
     87 
     88 # Restrictions used for associations (peer, server, pool).
     89 
     90 restrict source nomodify notrap noquery
     91 
     92 # Fewer restrictions for the local subnet.
     93 # (Uncomment and adjust as appropriate.)
     94 
     95 #restrict 192.0.2.0 mask 255.255.255.0 limited kod nomodify notrap nopeer
     96 #restrict 2001:db8:: mask ffff:ffff::  limited kod nomodify notrap nopeer
     97 
     98 # No restrictions for localhost.
     99 
    100 restrict 127.0.0.1
    101 restrict ::1
    102 
    103 # Hereafter should be "server", "peer", or "pool" statements to configure
    104 # other hosts to exchange NTP packets with.
    105 #
    106 # See <http://support.ntp.org/bin/view/Support/DesigningYourNTPNetwork>
    107 # and <http://support.ntp.org/bin/view/Support/SelectingOffsiteNTPServers>
    108 # for advice.
    109 #
    110 # Peers or servers should be selected in such a way that the network
    111 # path to them is short, uncongested, and symmetric (that is, the series
    112 # of links and routers used to get to the peer is the same one that
    113 # the peer uses to get back).  The best place to start looking for NTP
    114 # peers for your system is within your own network, or at your Internet
    115 # Service Provider (ISP).
    116 #
    117 # Ideally, you should select at least three other systems to talk NTP
    118 # with, for an "what I tell you three times is true" effect.
    119 
    120 #peer an.ntp.peer.goes.here iburst
    121 #server an.ntp.server.goes.here iburst
    122 
    123 # The pool.ntp.org project coordinates public time servers provided by
    124 # volunteers.  See <http://www.pool.ntp.org>.  The *.netbsd.pool.ntp.org
    125 # servers are intended to be used by default on NetBSD hosts.
    126 #
    127 # The following pool statement will give you a random set of NTP servers
    128 # geographically close to you.  A single pool statement adds multiple
    129 # servers from the pool, according to the tos minclock/maxclock targets.
    130 # The "2" host is used to obtain both IPv4 and IPv6 addresses.
    131 #
    132 # The pool.ntp.org project needs more volunteers! The only criteria to
    133 # join are a nailed-up connection and a static IP address. For details,
    134 # see the web page <http://www.pool.ntp.org/join.html>
    135 
    136 pool 2.netbsd.pool.ntp.org iburst
    137