timed - The network time daemon
timed [-tME] [-n | -i network]
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 network 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 controlled 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 network 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.
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 daemon. 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 provides 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 configure NTP first.
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.
Specifies the command path. Contains messages traced for
the timed command. Contains information about the known
networks.
Commands: date(1), timedc(8), timedsetup(8)
Daemons: xntpd(8)
Functions: adjtime(2), gettimeofday(2)
timed(8)
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