DragonFly On-Line Manual Pages

NTPD.CONF(5)             DragonFly File Formats Manual            NTPD.CONF(5)

NAME
     ntpd.conf - Network Time Protocol daemon configuration file

DESCRIPTION
     This manual page describes the format of the ntpd(8) configuration file.

     ntpd.conf has the following format:

     Empty lines and lines beginning with the `#' character are ignored.

     Keywords may be specified multiple times within the configuration file.
     They are as follows:

     listen on address [rtable table-id]
             ntpd(8) has the ability to sync the local clock to remote NTP
             servers and, if this directive is specified, can act as NTP
             server itself, redistributing the local clock.

             Specify a local IP address or a hostname the ntpd(8) daemon
             should listen on to enable remote clients synchronization.  If it
             appears multiple times, ntpd(8) will listen on each given
             address.  If `*' is given as an address, ntpd(8) will listen on
             all local addresses using the specified routing table.  ntpd(8)
             does not listen on any address by default.  The optional rtable
             keyword will specify which routing table to listen on, if the
             operating system supports rdomains.  By default ntpd(8) will
             listen using the current routing table.  For example:

                   listen on *

             or

                   listen on 127.0.0.1
                   listen on ::1
                   listen on 127.0.0.1 rtable 4

     sensor device [correction microseconds] [weight weight-value] [refid
             string] [stratum stratum-value]
             Specify a timedelta sensor device ntpd(8) should use, if the
             operating system supports sensors.  The sensor can be specified
             multiple times: ntpd(8) will use each given sensor that actually
             exists.  Non-existent sensors are ignored.  If `*' is given as
             device name, ntpd(8) will use all timedelta sensors it finds.
             ntpd(8) does not use any timedelta sensor by default.  For
             example:

                   sensor *
                   sensor nmea0

             An optional correction in microseconds can be given to compensate
             for the sensor's offset.  The maximum correction is 127 seconds.
             For example, if a DCF77 receiver is lagging 70ms behind actual
             time:

                   sensor udcf0 correction 70000

             The optional weight keyword permits finer control over the
             relative importance of time sources (servers or sensor devices).
             Weights are specified in the range 1 to 10; if no weight is
             given, the default is 1.  A server with a weight of 5, for
             example, will have five times more influence on time offset
             calculation than a server with a weight of 1.

             An optional reference ID string - up to 4 ASCII characters - can
             be given to publish the sensor type to clients.  RFC 2030
             suggests some common reference identifiers, but new identifiers
             "can be contrived as appropriate."  If an ID string is not given,
             ntpd(8) will use a generic reference ID.  For example:

                   sensor nmea0 refid GPS

             A stratum value other than the default of 1 can be assigned using
             the stratum keyword.

     server address [weight weight-value] [rtable table-id]
             Specify the IP address or the hostname of an NTP server to
             synchronize to.  If it appears multiple times, ntpd(8) will try
             to synchronize to all of the servers specified.  The rtable
             option specifies which routing table should be used for
             connection attempts.  Hostname resolution will still happen using
             the default routing table.  If a hostname resolves to multiple
             IPv4 and/or IPv6 addresses, ntpd(8) uses the first address.  If
             it does not get a reply, ntpd(8) retries with the next address
             and continues to do so until a working address is found.  For
             example:

                   server 10.0.0.2 weight 5
                   server ntp.example.org weight 1 rtable 4

             To provide redundancy, it is good practice to configure multiple
             servers.  In general, best accuracy is obtained by using servers
             that have a low network latency.

     servers address [weight weight-value] [rtable table-id]
             As with server, specify the IP address or hostname of an NTP
             server to synchronize to.  If it appears multiple times, ntpd(8)
             will try to synchronize to all of the servers specified.  Should
             the hostname resolve to multiple IP addresses, ntpd(8) will try
             to synchronize to all of them.  For example:

                   servers pool.ntp.org
                   servers pool.ntp.org rtable 5

FILES
     /usr/local/etc/ntpd.conf     default ntpd(8) configuration file

SEE ALSO
     ntpd(8), sysctl(8)

HISTORY
     The ntpd.conf file format first appeared in OpenBSD 3.6.

CAVEATS
     When using different rtable options, ntpd(8) must be started in rtable 0.

DragonFly 6.5-DEVELOPMENT     September 21, 2011     DragonFly 6.5-DEVELOPMENT