Unruh, My message to David probably is most relevant.
Dave Unruh wrote: > "David L. Mills" <[EMAIL PROTECTED]> writes: > > >>Unrug, > > >>You are not accurately describing the ntpd clock filter. An accurate >>desciption would surely help the point you are making. > > > You are undoubtedly correct. I was reading the source code again loast > night and getting myself confused again. I do not think my comments about > the aging are correct. > > I think that the process is --look though the last 8 samples for the one > with the smallest delay, If that is the the latest one, use it and go to > the clock selection process. If not do not go to clock selection (ie ignore > the latest measurement). > > > >>Davde > > >>Unruh wrote: > > >>>Grian Utterback <[EMAIL PROTECTED]> writes: >>> >>> >>> >>>>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 >>>>> >>>>> >>> >>> >>>>I mis-spoke. It is actually the case that NTP prefers the sample of >>>>the eight from any one single source that has the least delay. After >>>>the sample is chosen, the samples from all the servers are then >>>>subjected to different criteria to determine which will be the final >>>>choice. Jitter and stratum both factor in. >>> >>> >>>Worse than that . Only if the latest sample is the one with the min delay >>>is it chosen Otherwise it is not. You can go for 16 or more samples never >>>using any of thembefor one fits the criteion. (actually the samples are >>>aged as well-- ie the delay is increased as they get olderbut that seems to >>>have little effect.) >>>) _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
