[ntp:questions] NTP offset doesn't change.

William Unruh unruh at invalid.ca
Fri Feb 13 00:16:45 UTC 2015


On 2015-02-12, Harlan Stenn <stenn at ntp.org> wrote:
> William Unruh writes:
>> ...  And what happens to B when A suddenly begins to
>> slew at 2000PPM?
>
> And how often does this happen?  Why does it happen?
>
> I'm pretty sure that ntpd will notice this and declare that source a
> falseticker quickly enough.

I agree, assuming ntpd is using enough other good sources. I was in fact
giving you ammuntion with that statement. Ie, if one increased the
default handling rate of ntpd from 500 PPM, then what would happen a
clock that B depended on suddenly sped up by 2000PPM, especially if A
depends only on that clock.  I do not know. could that cause
instabilities in ntp? I do not know. 


>
> Chrony and ntpd have fundamentally different definitions of what it
> means to "provide good time".

Not really. But it should be distrubing that chrony disciplines clocks
much better ( lower jitter) than does ntpd in normal situations. Why?
And does that have lessons that ntpd could learn from? 

>
> I don't respond to 1 in 8 of your messages.  More or less...

And as with ntpd does that mean you track the truth much more poorly
that if you did? :-)


>
> H



More information about the questions mailing list