[ntp:questions] Two servers is worst possible configuration

David L. Mills mills at udel.edu
Sat Feb 17 00:28:27 UTC 2007


Guys,

With respect, you are all off the point. Two servers are better than one 
and not as good as three. However, if either of two fast servers 
disagrees with the other more than few milliseconds, no majority clique 
is possible and both turn falsetick. Usually, this happens when the 
roundtrip delay is very small and some minor warp resluts in an empty 
intersection interval. The recommended workaround is to tinker mindist 
something above the default .005 second. Make it high enough so minor 
warps are ignored while major ones turn out the lights.

Dave

Harlan Stenn wrote:
>>>>In article <45d605bc$0$3134$ba620e4c at news.skynet.be>, Jan Ceuleers <janspam.ceuleers at skynet.be> writes:
> 
> 
> Jan> Given the fact that configuring two servers is worse than just one, and
> Jan> definitely worse than three, would it be an idea for ntpd to output a
> Jan> warning in its logfile about this:
> 
> Sounds interesting to me - I'd be happy to receive patches that do this.
> 
> Dave, If we can "know" that at the moment the local refclock is the only
> supplier of time, would that be a sufficient condition to allow the local
> refclock to sync to the local machine "now"?
> 
> H




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