On 2011-01-19, Mike S <mi...@flatsurface.com> wrote: > At 02:18 PM 1/18/2011, unruh wrote... >>Especially as ntpd uses only one of every 8 polls, > > Is this relatively recent behavior? I can't provide NTP version #s
Nope. It is very old behaviour. It is the filter at the beginning whose purpose is to select from the last 8 that item whose round trip time is smallest in the hope that this has the least assymetry in the outgoing and incoming times. If there is sever assymmetry then this may help. In many cases it only succeeds in throwing away 88 percent of the data collected. > immediately, but it used to be I could "watch ntpq -p", and see the > offset and jitter change with each poll. More recently, I don't see > this. I haven't counted, but 1 of 8 sounds about right. > > Is it ignoring 7 of 8 (if so, why, instead of 8x polling interval?), or > is it averaging the 8, then using the average? It takes the one with the least round trip time of the last 8. Thus exactly which one is chosen is somewhat random. _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
