1TIMED(8) System Manager's Manual TIMED(8)
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6 timed - time server daemon
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9 timed [ -t ] [ -M ] [ -n network ] [ -i network ]
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12 Timed is the time server daemon and is normally invoked at boot time
13 from the rc(8) file. It synchronizes the host's time with the time of
14 other machines in a local area network running timed(8). These time
15 servers will slow down the clocks of some machines and speed up the
16 clocks of others to bring them to the average network time. The aver‐
17 age network time is computed from measurements of clock differences
18 using the ICMP timestamp request message.
19 The service provided by timed is based on a master-slave scheme. When
21 timed(8) is started on a machine, it asks the master for the network
22 time and sets the host's clock to that time. After that, it accepts
23 synchronization messages periodically sent by the master and calls adj‐
24 time(2) to perform the needed corrections on the host's clock.
25 It also communicates with date(1) in order to set the date globally,
27 and with timedc(8), a timed control program. If the machine running
28 the master crashes, then the slaves will elect a new master from among
29 slaves running with the -M flag. A timed running without the -M flag
30 will remain a slave. The -t flag enables timed to trace the messages
31 it receives in the file /usr/adm/timed.log. Tracing can be turned on
32 or off by the program timedc(8). Timed normally checks for a master
33 time server on each network to which it is connected, except as modi‐
34 fied by the options described below. It will request synchronization
35 service from the first master server located. If permitted by the -M
36 flag, it will provide synchronization service on any attached networks
37 on which no current master server was detected. Such a server propa‐
38 gates the time computed by the top-level master. The -n flag, followed
39 by the name of a network which the host is connected to (see net‐
40 works(5)), overrides the default choice of the network addresses made
41 by the program. Each time the -n flag appears, that network name is
42 added to a list of valid networks. All other networks are ignored.
43 The -i flag, followed by the name of a network to which the host is
44 connected (see networks(5)), overrides the default choice of the net‐
45 work addresses made by the program. Each time the -i flag appears,
46 that network name is added to a list of networks to ignore. All other
47 networks are used by the time daemon. The -n and -i flags are meaning‐
48 less if used together.
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51 /usr/adm/timed.log tracing file for timed
52 /usr/adm/timed.masterlog log file for master timed
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55 date(1), adjtime(2), gettimeofday(2), icmp(4P), timedc(8),
56 TSP: The Time Synchronization Protocol for UNIX 4.3BSD, R. Gusella and
57 S. Zatti
584.3 Berkeley Distribution November 17, 1996 TIMED(8)