Unruh wrote: > [EMAIL PROTECTED] (Manuel Beicht) writes: > >> Hi! > >> 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. > > Yes, * means it is the selected source. that ntp will slowly try to sync > to. > > >> 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 > > If you have an offset of 1000 ntp will carry out a step when it decides > that that is a genuine (ie, that the minimum offset recorded during 8 > polling intervals) offset. > If you have an offset of 1000 something is very wrong with your network > connection or your system. >
Unless he introduced the error deliberately in order to "test" NTP. > >> 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. > > It is slow to decrease the poll interval. > > >> 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. > > That is unusual. What kind of network connection do you have? A telephone > modem connection? For a high speed connection, the usual offset is in the > 10s of microsecond range for a local server, and 100s of microseconds for a > relatively local machine. Even half way across the continent with a delay > of 45ms, the offset is 100s of microseconds. > > > > >> Is that still ok? What is the acceptable range usually? > >> I would be very glad if you could provide me with some help. > >> thanks > >> Manuel > >> -- >> Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! >> Ideal f|r Modem und ISDN: http://www.gmx.net/de/go/smartsurfer _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
