[ntp:questions] NTP-Question about "ntpq -p"

Manuel Beicht manuel.beicht at gmx.de
Thu Aug 28 16:41:38 UTC 2008


I have some questions regarding synchronization and the output of "ntpq -p". For example what is the significance of the "*" for example when you run ntpq -p. Is this star a must because I have seen the polling sometimes and the time mostly accurate but the "*" is missing. So does the server have to have a "*" to be synched?  In ntp documentation I read it just means that "*" denotes the server that the NTP client is synching to but not necessarily that they are IN synch. I am asking so far I considered any server without a "*" out of synch. 

Then I noticed the polling is dynamic but it seems to be too long with some intervals and in particular too long when there is an offset. For example if we have an offset of 1000 the polling is at 128 or at 256 instead of 64 or a lower level which I think would be more logical. There are actually some posts on the ntp support sites that mention using custom polling parameters based on the offset and latency ect...that do polling at 10 min 15 max and there is some type of algorithm to find a match for anyone site. 

Also what is acceptable offset and jitter? We currently experience 20-40ms offset and 20-30ms jitter. sometimes it is up to 100-120ms offset.

Is that still ok? What is the acceptable range usually?

I would be very glad if you could provide me with some help.



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