Patrick Shanahan wrote:
* Joachim Schrod
[11-07-05 11:30]: ntpq -c pe
It tells you about all time sources, which one is used currently, and if you're synchronized.
Of this display, what indicates you are synchronized?
If you have a server with an asterisk in front, you're synchronized to that server. If it has a plus in front, this is a potential source of synchronization. E.g., my internal time server has the output remote refid st t when poll reach delay offset jitter ============================================================================== LOCAL(0) LOCAL(0) 10 l - 64 377 0.000 0.000 0.008 *ntp2.ptb.de .PTB. 1 u 887 1024 377 44.424 0.697 0.826 +rustime01.rus.u .DCFp. 1 u 968 1024 377 38.228 -2.858 0.927 +hora.cs.tu-berl .PPS. 1 u 3 1024 377 48.561 -3.353 1.365 This means I'm synchronized to PTB, and if that connection gets lost, rustime01 and hora could take over. (All three servers are stratum 1 servers and give definitive times. PTB is the reference time source for Germany.) The when column is a counter that is increased until it reaches the poll number, then the next ntp request is sent. The reach column are the octal representation of 8 bits that tell when we did reach the server in the past. This is a shift register -- if it's 377, that's best, all past requests were successful. delay, offset, and jitter (all are in milliseconds) show the difference of my time server to the reference servers. More info: http://www.meinberg.de/download/docs/other/ntp_adv.txt Another tip: There is a nice Nagios plugin that checks that the time server is up and running correctly; one gets an email if it gets non-functional. Cheers, Joachim -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Joachim Schrod Email: jschrod@acm.org Roedermark, Germany