chowalit.lab Chowalit Lab Linux wrote: > - My clients are windows XP, Windows 2003, Linux. > > My question: > - How to check the different time between NTP server and client on > NTP server side.
That will be very difficult for the Windows ones. For the Linux ones, add code to the clock interrupt routine that pulses a printer port line or modem control signal (do not use USB ports), and simultaneously writes the offset between the software clock time and the nominal, round number of milliseconds, tick time, to a buffer. At user level copy that buffer to a file. Do this on both client and server. Set up some suitable instrumentation to measure and log the time delay between the pulses on client and server, then process the results in conjunction with the client and server's idea of the time at the time of the pulse. This assumes that the machines are electrically close. Don't worry too much on Windows, as the time is likely to be more accurate than the resolution with which ordinary application programs can read it. If you are using w32time on XP, don't worry, because w32time is not intended for precision time keeping on that platform, and doesn't default for it on 2003. If you want to measure the value during the startup and other transients that Dave Mills considers unimportant, use ntpq on the server. This will not work for any machines using w32time. You might also configure the client as an ignored server for the server, or maybe peering them, to allow ntpq peers run on the server, against the server, to give a reverse "offset" value. Note these methods only give you historical information. For a near instantaneous snapshot, use ntpdate -d. The reason you are getting such complex answers is that you are asking to measure something that, in an ideal system, is theoretically unmeasurable. _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
