[ntp:questions] NTP setup in time sensitive environment

Charles Swiger cswiger at mac.com
Wed Apr 22 22:54:18 UTC 2015

On Apr 22, 2015, at 3:24 PM, NVAP <nvap23 at gmail.com> wrote:
> *Questions:*
> 1) How can we assure that the sync will consistently result in +/- 5ms offset?

If you weren't rebooting the Windows boxes potentially several times a day,
Windows might do better.  I've seen RRD graphs of stratum-2 Win 7 boxes
that meet your tolerance-- for example:


> 2) This seems to defeat the whole purpose of synching if the offset cannot
> be maintained!
> Is there a way to force the system offset to remain within +/-5ms?

I'm not convinced that tuning the clients to use burst and minpoll 3 / maxpoll 6 is helping.
Wasn't there a bug in Windows where very small offsets?  Ah, yes:


Get rid of burst and try minpoll 6 maxpoll 8.

> 3) Can we live with just 1 time server PC_NTP and PC_V, PC_A and PC_B will
> closely following that time no matter?

Yes.  Of course, if something happens to PC_NTP, it will become a single point of failure.


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