TIMED(8)                  BSD System Manager's Manual                 TIMED(8)

NAME
     timed - time server daemon

SYNOPSIS
     timed [-M] [-t] [-i network] [-n network]

DESCRIPTION
     This is the time server daemon and is normally invoked at boot time from
     the rc(8) file.  It synchronizes the host's time with the time of other
     machines in a local area network running timed 8. These time servers will
     slow down the clocks of some machines and speed up the clocks of others
     to bring them to the average network time.  The average network time is
     computed from measurements of clock differences using the ICMP timestamp
     request message.

     The service provided by timed is based  on a master-slave scheme.  When
     timed 8 is started on a machine, it asks the master for the network time
     and sets the host's clock to that time.  After that, it accepts synchro-
     nization messages periodically sent by the master and calls adjtime(2) to
     perform the needed corrections on the host's clock.

     It also communicates with date(1) in order to set the date globally, and
     with timedc(8),  a timed control program.  If the machine running the
     master crashes, then the slaves will elect a new master from among slaves
     running with the -M flag.  A timed running without the -M flag will re-
     main a slave.  The -t flag enables timed to trace the messages it re-
     ceives in the file /var/log/timed.log. Tracing can be turned on or off by
     the program timedc(8).  Normally timed checks for a master time server on
     each network to which it is connected, except as modified by the options
     described below.  It will request synchronization service from the first
     master server located.  If permitted by the -M flag, it will provide syn-
     chronization service on any attached networks on which no current master
     server was detected.  Such a server propagates the time computed by the
     top-level master.  The -n flag, followed by the name of a network which
     the host is connected to (see networks(5)),  overrides the default choice
     of the network addresses made by the program.  Each time the -n flag ap-
     pears, that network name is added to a list of valid networks.  All other
     networks are ignored.  The -i flag, followed by the name of a network to
     which the host is connected (see networks(5)),  overrides the default
     choice of the network addresses made by the program.  Each time the -i
     flag appears, that network name is added to a list of networks to ignore.
     All other networks are used by the time daemon.  The -n and -i flags are
     meaningless if used together.

FILES
     /var/log/timed.log        tracing file for timed
     /var/log/timed.masterlog  log file for master timed

SEE ALSO
     date(1),  adjtime(2),  gettimeofday(2),  icmp(4),  timedc(8),

     R. Gusella, and S. Zatti, TSP: The Time Synchronization Protocol for UNIX
     4.3BSD.

HISTORY
     The timed daemon appeared in 4.3BSD.

4.3 Berkeley Distribution       March 27, 1993                               1