[ntp:questions] Bug 2341 - ntpd fails to keep up with clock drift at poll>7
david-taylor at blueyonder.co.uk.invalid
Tue Dec 3 08:59:15 UTC 2013
On 03/12/2013 00:34, Brian Inglis wrote:
> BTDT, but we all still need decent network servers as check and backup
> in case
> there are ref clock issues - we don't all have an in house NTP Server
> farm! ;^>
Yes, having good Internet servers as a backup or check is desirable, if
not mandatory. I recall that in the early days with Windows before all
the interpolation and other improvements were added to NTP I was
plotting offsets on a +/- 100 ms scale - that's how bad it was.
If someone can only use Internet servers, it's better to have a small
(e.g. Raspberry Pi) Linux or FreeBSD local server, or perhaps a Windows
8.1 box, syncing to the Internet, and to which the Windows PCs are
synced with a small poll interval (say 32 seconds). For the RPi alone:
I've not tried Windows directly taking its time from the Internet for
quite a while except on holiday, when I saw offsets in the 10 -25
millisecond range, and averaged jitter up to 30 milliseconds. This
through whatever Wi-Fi connections were available. The offset did
converge, though. Poll interval started at 64, but never got higher
than 256 seconds over a couple of hours of use.
Hope that helps.
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