[ntp:questions] strange behaviour of ntp peerstats entries.

David J Taylor david-taylor at blueyonder.neither-this-bit.nor-this-bit.co.uk
Wed Jan 30 19:13:57 UTC 2008

Dennis Hilberg, Jr. wrote:
> David J Taylor wrote:
>> Brian Utterback wrote:
>> []
>>> Which is why NTP prefers the source with the smallest delay. The
>>> system I am using has servers whose delays are 51ms to 94. I can't
>>> find any closer. On my company LAN, the delays range from 16ms to
>>> 87ms. The offsets of all these servers agree to within 9ms. Sure, I
>>> am not going to get sub-millisecond from that, but I think it is
>>> probably
>>> more typical than your set-up.
>>> Brian Utterback
>> Brian,
>> I know this is supposed to happen, but I recall seeing behaviour
>> some time ago where a server with a little more jitter and much more
>> delay was preferred, almost as if it was the jitter/offset which was
>> the measure rather than offset itself.  I ended up adding a "prefer"
>> qualifier. Cheers,
>> David
> Doesn't ntpd choose a peer based on stratum also?  Maybe that was the
> issue there.

Indeed it does, but IIRC the remote server was at the same or higher 
stratum.  Since using "prefer" and my own GPS-based stratum 1 server I 
don't see the issue any more.



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