[ntp:questions] ATOM falseticker with flag3 enabled
agcarver+ntp at acarver.net
Fri Mar 30 00:44:45 UTC 2012
On 3/29/2012 03:29, David Lord wrote:
> Dave Hart wrote:
>> On Thu, Mar 29, 2012 at 02:44, A C <agcarver+ntp at acarver.net> wrote:
>>> Without flag3 it appears that ntpd does the heavy lifting but is
>>> unable to
>>> use the PPS unless a prefer peer is set. With flag3 enabled, PPS is
>>> without a prefer peer.
>> Being unable to use the PPS unless either a prefer peer is set or
>> another knob is adjusted (see what I quoted earlier) is operating by
>> design. The change in operation with flag3 1 seems likely to me to be
>> an ntpd bug, which is why I'd like to see a bug report filed. Unless
>> I'm missing some design intention, it seems to me PPS should not
>> become reachable with no prefer peer regardless of flag3.
> On NetBSD-5, i386, I had the PPS marked as falseticker as
> from March 2, 2012 when I updated from 4.2.6p3 to 4.2.6p5.
> When I went back to 4.2.6p3 the 'o' was back. I hadn't spare
> time to investigate and changed config to use only type 20
> nmea driver with 4.2.6p5.
Interesting, so that's the same OS on two platforms with similar
problems. Did you happen to also observe your minimum jitter times in
the upgrade? When I run 4.2.6 my minimum jitter is reported as 0.061ms.
But in 4.2.7 the minimum jitter is 0.122ms, exactly double the 4.2.6
I'm still tinkering with my configuration to see if I can get ATOM to
stop being a false ticker but no luck yet even though it's still
disciplining the clock.
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