[ntp:questions] "ntpd[7602]: synchronized to"

Chuck Swiger cswiger at mac.com
Thu May 26 18:38:19 UTC 2011


On May 26, 2011, at 10:48 AM, Miroslav Lichvar wrote:
>> Evidently yes for your case.  With only two servers, it may not be
>> possible to find a best intersection via ntpd's variant of
>> Marzullo's algorithm:
> 
> I think the frequent source switching can happen with any number of
> sources if the two best servers have similar synchronization distance.

Yes, I agree that it _could_ happen with any number of sources.

> With more servers you may have a better chance that the best server is
> significantly better than the others though.

...but, if you have a decent number of timeservers, the stability seems to improve significantly, and a change to the server rated as best seems to happen more in response to legitimate issues like a network problem somewhere, a timeserver being bounced, etc.

> The problem can be usually fixed by increasing the anti-clockhopping
> distance by "tos mindist", perhaps to 10 ms.

This might be a useful suggestion for Florin, but I don't recall running into clockhopping issues with any great frequency even when I was running the older ntp-4.2.2 versions some years ago.

Regards,
-- 
-Chuck




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