gluino wrote: > Hi all, > > I am using the default ntpd setup in plain redhat box. Default > settings except for specifying a nearer time server. > Everything seems fine (ntpq pasted below), and it has been left alone > for months. > Said box hardly receives human attention, and is depended on for time > sync by a couple hundred local machines. > > My question is: how would I know if ntpd has problems. I'm thinking of > some kind of alert when ntpd is unable to contact any good time > servers, for example. > > # ntpq -np > remote refid st t when poll reach delay > offset jitter > ============================================================================== > 203.117.180.36 .INIT. 16 u - 1024 0 0.000 0.000 > 4000.00 > +64.109.43.141 130.149.17.21 2 u 534 1024 377 313.466
The delay of 313.466 milliseconds means this server is too far away to be useful! > -19.302 2.021 > +64.246.40.39 67.15.110.21 3 u 505 1024 377 253.106 > -13.209 0.184 This server, also, is too far away to be useful > 127.127.1.0 LOCAL(0) 10 l 60 64 377 0.000 > 0.000 0.001 The local clock is usually NOT a good source of time! > *203.117.180.36 .ACTS. 1 u 582 1024 337 31.425 > 4.047 1.380 > > Assume the above is healthy? > > Thanks very much. > gluino > You assume a lot! If possible, select at least four internet servers with delay values less than 20 milliseconds! If this is not possible, consider purchasing and installing a GPS reference clock; the Garmin GPS18LVC can be bought for less than $100 US. _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
