NTP Server setting

[Achilles_2]

Can everyone explain me about NTP? I have 3 machines and use one of them as master clock server. I don't know how to set it to master (or it needn't configure?) On the other side, I configure /etc/ntp.conf and /etc/rc.config.d/netdaemons files in other 2 servers and then start xntpd. But they failed. They show the error
ntpdate: no server suitable for synchronization found

Thanks you for your help

[C. Beerse_1]

To start at the end, ntpdate does not use /etc/ntp.conf. You have to give it an ntp-host to sync with. You can try "pool.ntp.org". Then, ntpdate and the ntp-deamon cannot run at the same time, they use the same port.

In /etc/ntp.conf (or with `sam`) you just need to specify other ntp-servers. Best to specify either 1 or 3, not 2: with 2, it cannot find the best among the 2. A server is regarded as having a better time than the local machine. You can regard this as a 'master'.

You can also specify peer-s: machines with the same time quality. For example 1 server from the internet provider and 3 internal servers: each internal server has the others as peer and the providers as server.

Other internal machines either use one of the internal clocks or all three, using them as their master. If servers are a kind of team (like the fileservers) you can define them peers among eachother.

If you use `ntpq -p` on the machine, you can see the peers and servers. Under the stratum number, you can see their level in the hierarchy.

If your provider has no reference clock, you can use pool.ntp.org, see www.pool.ntp.org.