[ntp:questions] Two time sources with offset => fails to synchronize

Richard B. Gilbert rgilbert88 at comcast.net
Tue Feb 12 15:40:50 UTC 2008

Thierry MARTIN wrote:
> Hi all,
> I am running ntp 4.2.0 on FC5.
> Two time sources:
>     - embedded GPS board(Meinberg board)
>     - remote Radio clock synchronized ntp server (stratum 1)
> It seems that the Radio clock has 50ms offset compared to the GPS 
> source, which leads a failure in synchronisation.
> I am looking for some documentation that explain why it fails.
> Which parameter(s) in the configuration triggers that behaviour?
> I used the "prefer" keyword in the GPS configuration line, with the same 
> result. Is there a way to make it work better?
> Thanks for you help
> Thierry MARTIN

You could add a third and even a fourth source of time.  You could also 
account for the offset in the Radio Clock due to propagation delay.  I 
don't remember the syntax but you can specify the delay in ntp.conf.

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