[ntp:questions] Double "prefer" configuration

Eugen COCA ecoca at eed.usv.ro
Fri Mar 2 08:30:34 UTC 2007

> I would drop gps-1.mit.edu and gps-2.mit.edu.  Their delays are high
> enough that they are unlikely to be selected as a synchronization
> source.  Any benefit you might gain is probably too small to justify
> using them.

All other servers except the GPS and the PPS are with the "noselect"
keyword and are only for statistics there.


> Is something wrong with your GPS?  It appears to have been inoperative
> for 85 hours!

Yes, the GPS is powered off. There is only the PPS signal from the
rubidium frequency standard working.

> I don't know about two "prefer" keywords.  I had the impression that
> only one was supported but I could be wrong.

This is the question. Without the second "prefer" in the PPS driver,
after the GPS "death" the server will remain without any source
for synchronization. I make an experiment with:

server minpoll 6 maxpoll 6 prefer
fudge flag3 0 time1 0.000 refid GPS

server minpoll 4 maxpoll 4 prefer
fudge flag3 1 time1 0.000 refid PPS

and I asked if any NTP developer could tell me if there is something
wrong in what I'm trying to do.

> Other than that, it looks fine to me!

Thank you !

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