[ntp:questions] Re: ntp sanity limit kills ntp daily

Steve Kostecke kostecke at ntp.isc.org
Fri May 20 19:54:21 UTC 2005

On 2005-05-20, Michael Ward <michaelward at sprintmail.com> wrote:

> I happen to agree that the clock loosing about 1200 seconds (for any 
> reason) seems insane.  However, given that this sort of behavior seems 
> common enough to be found via google (search for: ntp exceeds sanity 
> limit), I'm hopeful that there is a way to coax ntp (or some other 
> automated program) to trudge on and do the deed anyway.

A 20 minute clock skew is a good indication that something is not right.

If may help to operate this host as a broadcast/multicast client so
that it receives NTP packets more often than every 1024 seconds. Or, if
you are syncing with an internal time server you might try reducing the

It will take ntpd quite a while to correct a 1200 second clock
error. If you _really_ want top override the panic limit see
http://www.eecis.udel.edu/~mills/ntp/html/miscopt.html and look for
'panic' in the 'tinker' section. However it is possible that your clock
will never be correct if you go that route.

Another option is restarting ntpd (don't forget the '-g' option) to step
the clock after the back-up is complete.

Steve Kostecke <kostecke at ntp.isc.org>
NTP Public Services Project - http://ntp.isc.org/

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