NAME

       ntpd.conf - Network Time Protocol daemon configuration file

DESCRIPTION

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

       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.

       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
              OpenNTPd  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.  ntpd(8) does not
              listen on any address by default.  For example:

              listen on *

              or

              listen on 127.0.0.1
              listen on ::1

       sensor device [correction microseconds] [weight weight-value]
              Specify a timedelta sensor device ntpd(8) should use.  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 udcf0

              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 15ms behind actual
              time:

              sensor udcf0 correction 15000

       server address [weight weight-value]
              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.  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

              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]
              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

FILES

       /etc/openntpd/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 .

                                           $Mdocdate: October 2 2007 $                              NTPD.CONF(5)