On 2018-08-06, David Woolley <david@ex.djwhome.demon.invalid> wrote: > On 06/08/18 08:16, ashishchugh....@gmail.com wrote: >> 3- Is there is any way through i can determine that what is the currently >> difference between my local system and ntp server. > > No. If you could, NTP could modify the local time to make the value zero.
That is of course what it tries to do, without jumping the local time (which would be bad). Of course the whole chain (Your program, your network hardware, the network, various routers etc along the way, the remote machine hardware, the remote software and back again) introduces noise, so you do not know that the remote ntp server's time is. But in the logs it will tell you what the difference is between the local time and the estimate of the remote time is obtained from that noisy chain. That is the best you can do. Of course you could attach your ssytem to gps, and get the remote gps server's time to 10s or 100s of nanosecond accuracy. And yo ucould use that to see how far your system is off the remote server, If you could borrow a gps, you could test your system. If you bought a gps, then the best idea would be to use it as your server, and get your machine disciplined to sub microsecond accuracy. From network servers, you can expect 10s of microseconds (nearby servers-- like in the same building) to millisec for distant servers. For gps, it depends on how you feed the gps into your system. Here you can get 100s of nanoseconds to a few microseconds using chrony. _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
