[ntp:questions] [help]how to configure ntp in a private network and without extra refer clock source?

David Woolley david at ex.djwhome.demon.invalid
Thu Nov 15 14:04:11 UTC 2012

Jun Hu wrote:

> I want  those clients  is synchonized to Server A  or Server B ,

NTP is only suitable when there is a single standard of time.  That
means that one of these servers must use the other as its timing source;
they can't free run individually, unless they are both synchronised from
some common time source, outside of NTP.

Also, ntpd doesn't synchronise to just one of the available servers; it
synchronises to a weighted average of the time from all the valid
servers (see clock_combine in ntp_proto.c), so normal clients will
synchronize to a mix of the times on the two servers, assuming they are
both up and have compatible times.

If the times are not compatible, there is a risk that both will get
rejected - I'm not sure whether ntpd will throw out its last server as a
falseticker, or not.

What you probably need to do is to use orphan mode between server A and
B and accept that the clients will use a mixed time from both servers.

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