TIMED(8) System Manager's Manual TIMED(8)
NAME
timed - time server daemon
SYNOPSIS
timed [ -t ] [ -M ] [ -n network ] [ -i network ]
DESCRIPTION
Timed 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 net-
work 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 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 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 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 appears, 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
/usr/adm/timed.log tracing file for timed
/usr/adm/timed.masterlog log file for master timed
SEE ALSO
date(1), adjtime(2), gettimeofday(2), icmp(4P), timedc(8),
TSP: The Time Synchronization Protocol for UNIX 4.3BSD, R. Gusella and S. Zatti
4.3 Berkeley Distribution November 17, 1996 TIMED(8)