[ntp:questions] Keeping NTP Honest

Unruh unruh-spam at physics.ubc.ca
Mon Jul 13 17:04:38 UTC 2009


Evandro Menezes <evandro at mailinator.com> writes:

>On Jul 12, 3:21=A0pm, Unruh <unruh-s... at physics.ubc.ca> wrote:
>>
>> The way ntp works, faster polling also means worse rate estimation and
>> more annoyance of the providers of the time. The current setup is done
>> that way to try to minimize the rate error, so if your sconnection to
>> ntp goes down, your system can freewheel with the greatest accuracy.

>But that's the issue: NTP allows for good freewheeling if it comes to
>that, provided that the system maintained in STP and in a vacuum.

>In the real world, ambient temperature changes frequently even in
>conditioned environments, network load affects packet jitter, etc.
>And all this also affects a system's peers, compounding the issue of
>NTP's slow reaction time.

Use chrony. Much much faster reaction time and better clock control.
However you must be running Linux (yet another reason to change).
It now also has harware clock support (shm refclock) in git.
Or use the temperature controlled ntp ( reads the temp and uses that to
estimate the clock rate changes due to temp variations)

>Thanks.




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