timed(8)timed(8)NAMEtimed - The network time daemon
SYNOPSIStimed [-tME] [-n | -i network]
OPTIONS
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. Specifies that a
machine can become the time server if the master time server
becomes inoperative. See RESTRICTIONS for more information.
Overrides the input of slaves. Use the -E option in conjunction
with the -M option. It specifies that a master timed system
will not average the times of the slaves to calculate the net‐
work 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 con‐
trolled by an outside agent (such as the Network Time Protocol
(NTP)). 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 net‐
work 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. 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 dae‐
mon. 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 daemon 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 corrections 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
Specifies the command path. Contains messages traced for the timed
command. Contains information about the known networks.
SEE ALSO
Commands: date(1), timedc(8), timedsetup(8)
Daemons: xntpd(8)
Functions: adjtime(2), gettimeofday(2)timed(8)
