TIMED(8-BSD)        RISC/os Reference Manual         TIMED(8-BSD)



NAME
     timed  - time server daemon

SYNOPSIS
     /etc/timed [ -t ] [ -M [ -a ] ] [ -n network ] [ -i network
     ]

DESCRIPTION
     timed is the time server daemon and is normally invoked at
     boot time.  It synchronizes the host's time with the time of
     other machines in a local area network running timed.  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 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 synchronization messages
     periodically sent by the master and calls adjtime(2) to per-
     form 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 remain a
     slave.  The -t flag enables timed to trace the messages it
     receives in the file /usr/adm/timed.log.  Tracing can be
     turned on or off by the program timedc(8).  timed normally
     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 synchronization service on any attached net-
     works on which no current master server was detected.  Such
     a server propagates the time computed by the top-level mas-
     ter.  When the -a flag is present, the local clock is con-
     sidered accurate and will not be synchronized.  Often, the
     accurate clock will be maintained by other protocols and a
     timed master will distribute the time to slave hosts on the
     local network.  The -n flag, followed by the name of a net-
     work which the host is connected to (see networks(4)), over-
     rides the default choice of the network addresses made by
     the program.  Each time the -n flag appears, that network
     name is added to a list of valid networks.  All other net-
     works are ignored.  The -i flag, followed by the name of a
     network to which the host is connected (see networks(4)),
     overrides the default choice of the network addresses made
     by the program.  Each time the -i flag appears, that network



                         Printed 1/15/91                   Page 1

TIMED(8-BSD)        RISC/os Reference Manual         TIMED(8-BSD)



     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.

BOOT-TIME CONFIGURATION
     At system boot-time, the file /etc/timed.conf is read to
     determine the machine default configuration.  The first line
     contains the master/slave configuration and should have
     either ``Master'' or ``Slave''.  The second line of the con-
     figuration file contains other options to pass on the com-
     mand line.  For example,

     Master
     -i MipsEngineering

     will execute ``/etc/timed -M -i MipsEngineering''.

FILES
     /etc/timed.conf              configuration file for timed
     /usr/adm/timed.log           tracing file for timed
     /usr/adm/timed.masterlog     log file for master timed

SEE ALSO
     timedc(8), icmp(7P).
     date(1) in the User's Reference Manual.
     adjtime(2), gettimeofday(2), in the Programmer's Reference
     Manual.
     TSP: The Time Synchronization Protocol for UNIX 4.3BSD, R.
     Gusella and S. Zatti


























 Page 2                  Printed 1/15/91