Max Grobecker <[email protected]> writes: > Routing should be totally insignificant to the NTP offsets, since NTP > measures the packet round-trip and recalculates the timestamps > received. So, even if the packet needs thousands of milliseconds to > get around the internet, your time should be +/- 1ms accurate.
That's true if the replies follow the same route (in reverse) as the requests and all links are symmetrical. If that is not the case - and the odds are worse the further away you are - the calculated offset will be incorrect. I blogged about this a few years ago when my server's offset was alternating between two values: https://blog.des.no/2012/07/ntp-and-asymmetric-routes/ You can also look at my server's current stats: http://www.pool.ntp.org/scores/194.63.250.121 The offset measured by the LA monitoring station varies wildly between -2 and -8 ms, but my server reports sub-millisecond offsets (median of absolute value: 184 µs) to its nine stratum 1 peers. DES -- Dag-Erling Smørgrav - [email protected] _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
