[ntp:questions] Re: xntpd keeps increasing its offset w.r.t preferred stratum 1 server

David Woolley david at djwhome.demon.co.uk
Tue Nov 9 20:59:01 UTC 2004

In article <m67kd.15694$Z7.528856 at news20.bellglobal.com>,
Yatin Shelke <yatinruchi at sympatico.ca> wrote:

> What I find is that on starting xntpd, my offset gradually increases from 0
> to somewhere between 1000 - 2000 milliseconds w.r.t the preferred stratum 1
> server, and then, xntpd resets itself. Any idea what is causing xntpd to

It should start the reset process by the time it reaches 128ms.  If it
has reached 1000ms in the time it takes to complete the reset sequence
(about 20 minutes), your clock frequency is way too far outside the
500ppm capture range.  If the drift over this time varies by 1 second,
the clock is unstable, so you can't even hope to do a coarse correction
with tickadj.

> behave this way, especially, when the preferred server is stratum 1, and the
> local CPU clock has been fudged to stratum 11?

If the clock is that bad, you should not be using a stratum 1 server,
unless you own it.  You should also not be configuring a local clock
as no down stream machine should be relying on time from you.  (Many
people mistakenly configure local clock drivers.)

Note that ntpd can drift out of the 128ms band once or twice in startup,
but it shouldn't be drifting fast enough to be able to reach 1 second!

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