[ntp:questions] Unable to synchronise meinberg ntp server to clients.

Chuck Swiger cswiger at mac.com
Fri Sep 16 00:43:22 UTC 2011

On Sep 15, 2011, at 4:30 PM, unruh wrote:
>> I recall OS vendors shipping an ntp.conf using "minpoll 12 maxpoll 17"...
> Well, if you do not care that you are never synchronized, I suppose it
> does not matter.

Are you claiming that such a config will never become synchronized?

If so, you're simply wrong.

> minpoll 12 means thatthe polling interval is 1 hr, and
> since only one in 9 polls are kept (on average) this would mean 8 hours
> per data point. And ntpd converges slowly, so it would be weeks before
> your system had converged to the right time ( assuming you did not have
> a crash or a shutdown before that). Ie, why in the world would anyone do
> that?

Try using a system which invokes "ntpdate -b" (or "sntp -r", etc) either during boot, or as needed upon resuming from sleep, in order to adjust the clock to within ten milliseconds or so, before running or restarting ntpd.  Even starting from scratch without a drift file, it takes perhaps a day or so for ntpd to calibrate the intrinsic drift using the config mentioned above, not weeks.

Now, I wouldn't recommend this config for a box which is being used as a timeserver to other machines, but for pure clients, it's fine.  At least, it's fine for Unix operating systems which don't have broken kernel timekeeping, and probably even recent flavors of Windows.


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