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timed(8)							     timed(8)



NAME

  timed	- The network time daemon

SYNOPSIS

  timed	[-tME] [-n  | -i network]

OPTIONS

  -i network
      Specifies	the names of the networks (as defined in the /etc/networks
      file) to be excluded from	clock synchronization. Each network name that
      is an argument to	the -i option is added to the list of networks that
      the timed	daemon will ignore.  If	the -i option is used, timed accesses
      all networks to which the	host is	connected except for the specified
      networks.

      If neither the -i	option nor the -n option is used, timed	tries to
      access all the network devices connected to the local host.

      Do not use the -i	and -n options together.

  -M  Specifies	that a machine can become the time server if the master	time
      server becomes inoperative. See RESTRICTIONS for more information.

  -E  Overrides	the input of slaves.  Use the -E option	in conjunction with
      the -M option.  It specifies that	a master timed system will not aver-
      age the times of the slaves to calculate the network time.  Instead, it
      distributes the time of its local	host as	the network time.  This
      option allows a master timed system to distribute	time to	a network
      while the	network	time is	controlled by an outside agent (such as	the
      Network Time Protocol (NTP)).

  -n network
      Specifies	the names of the networks (as defined in the /etc/networks
      file) to be included in clock synchronization. When timed	is started,
      it gathers information about all the network devices connected to	the
      local host.  The network argument	to the -n option is the	name of	the
      network that timed should	access.	If the -n option is used, only the
      specified	networks are accessed.

      If neither the -n	option nor the -i option is used, timed	tries to
      access all the network devices connected to the local host.

      Do not use the -n	and -i options together.

  -t  Enables tracing of messages received in /usr/adm/timed.log.






DESCRIPTION

  The timed daemon is not invoked at boot time by default.  You	can use	the
  /usr/sbin/timedsetup utility to configure the	timed daemon.

  The timed daemon synchronizes	the host's clock with those of other machines
  on the local area network that are also running the timed daemon. The	timed
  daemon slows the clocks of some machines and speeds up the clocks on other
  machines to create an	average	network	time. The average network time is
  computed from	measurements of	clock differences using	the Internet Control
  Message Protocol (ICMP) timestamp request message.

  The service provided by timed	is based on a master/slave (client/server)
  scheme.  When	timed is started on a machine, it asks the master timed	dae-
  mon for the network time and sets the	host's clock to	that time. After
  that,	the host accepts synchronization messages periodically sent by the
  master and calls the adjtime() system	call to	perform	the needed correc-
  tions	on the host's clock.

  The timed daemon also	communicates with the date command to set the date
  globally, and	with timedc, the timed control program.

  If the machine running the master ceases to function,	a machine that is
  running the timed daemon with	the -M option becomes the new master timed
  daemon.

				     Note

       The timed daemon	is provided for	compatibility. Tru64 UNIX also pro-
       vides support for the Network Time Protocol through the xntpd daemon.
       You should use NTP for time synchronization. If you need	to run both
       NTP and the timed daemon, you must run the timed	daemon with the	-E
       option.

       If you plan to run both the timed daemon	and NTP, you should also con-
       figure NTP first.

RESTRICTIONS

  In configurations with two or	more hosts each	connected to the same two or
  more subnetworks, only one of	the hosts can run the timed daemon by using
  the -M option.

FILES

  /usr/sbin/timed
      Specifies	the command path.

  /var/adm/timed.log
      Contains messages	traced for the timed command.

  /etc/networks
      Contains information about the known networks.

SEE ALSO

  Commands: date(1), timedc(8),	timedsetup(8)

  Daemons: xntpd(8)

  Functions: adjtime(2), gettimeofday(2)