[ntp:questions] ATOM falseticker with flag3 enabled

A C 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
>>> running
>>> 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 
value.

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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