NTPD.CONF(5)							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.

       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  sen-
	      sor 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 syn-
	      chronize 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  syn-
	      chronize 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)