[ntp:questions] Loopstats updated less frequently than expected
David Mills
mills at udel.edu
Sun May 24 03:37:19 UTC 2009
Bill,
Wrong. Please read the description of the clock filter algorithm again
and we can discuiss ir further.
Dave
Unruh wrote:
>"David J Taylor" <david-taylor at blueyonder.not-this-part.nor-this.co.uk.invalid> writes:
>
>
>
>>Folks,
>>
>>
>
>
>
>>I have the following entries in ntpd.conf:
>>
>>
>
>
>
>>server 192.168.0.2 iburst maxpoll 6
>>server 192.168.0.7 maxpoll 6
>>server 0.uk.pool.ntp.org minpoll 10
>>
>>
>
>
>
>>.. and the following as the most recent loopstats:
>>
>>
>
>
>
>>54974 37901.029 -0.000209922 13.840 0.000108471 0.007233 6
>>54974 38229.033 0.000346890 13.846 0.000221473 0.007179 6
>>54974 38754.041 -0.000217131 13.840 0.000287548 0.007132 6
>>54974 38954.047 -0.000091306 13.839 0.000272631 0.006682 6
>>
>>
>
>
>
>>I note that the times between these four entries are:
>>
>>
>
>
>
>>328s
>>525s
>>200s
>>
>>
>
>
>
>>As I have maxpoll set to 6, I would have expected entries no more than 64s
>>apart. What am I failing to understand here? The poll values reported in
>>ntpq -p are 64, 64 and 1024 - as expected.
>>
>>
>
>You are forgetting that ntp throws away 7/8 of the stuff it collects.
>(This is in an attempt to counter round trip biases).
>Thus you would expect to have 8 times the max poll interval between
>loopstats. (it is random so it is not always exactly 8 times sometimes
>less, but never more, but it averages out to pretty close to 8 times.)
>
>
>
>
>>Thanks,
>>David
>>
>>
>
>_______________________________________________
>questions mailing list
>questions at lists.ntp.org
>https://lists.ntp.org/mailman/listinfo/questions
>
>
More information about the questions
mailing list