24.2 Configuring xntp in the Network
The easiest way to use a time server in the network is to set server
parameters. For example, if a time server called
ntp.example.com is reachable from the network, add its
name to the file /etc/ntp.conf by adding the
following line:
server ntp.example.com
To add more time servers, insert additional lines with the keyword
server. After initializing xntpd with the command
rcntpd start, it takes about one hour
until the time is stabilized and the drift file for correcting the local
computer clock is created. With the drift file, the systematic error of
the hardware clock can be computed as soon as the computer is powered on.
The correction is used immediately, resulting in a higher stability of
the system time.
There are two possible ways to use the NTP mechanism as a client: First,
the client can query the time from a known server in regular intervals.
With many clients, this approach can cause a high load on the server.
Second, the client can wait for NTP broadcasts sent out by broadcast time
servers in the network. This approach has the disadvantage that the
quality of the server is unknown and a server sending out wrong
information can cause severe problems.
If the time is obtained via broadcast, you do not need the server name.
In this case, enter the line broadcastclient in the
configuration file /etc/ntp.conf. To use one or more
known time servers exclusively, enter their names in the line starting
with servers.