[ntp:questions] Client using Meinberg NTP can't sync with ntp server problem

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Fri Jul 11 01:43:36 UTC 2014

On 2014-07-10 08:43, Martin Burnicki wrote:
> Brian Inglis wrote:
>> You can start ntpd with -g option which allows it to step your system
>> time once,
>> when it first starts; using iburst "pool hk.ntp.pool.org iburst" will
>> allow the
>> correct offset to be set within about 16s after startup. Thereafter it
>> will stay
>> within +/-128ms of UTC; after it has settled, that should be about
>> +/-10ms off UTC.
>> As another poster said, adding "pool asia.ntp.pool.org iburst" may
>> improve your
>> offset.
>> Once it gets to long poll intervals, it actually improves the drift
>> compensation
>> more, and reduces the offset further.
> That's the theory how it should work, and how it does work on non-Windows systems.
> In practice ntpd v4.2.6p5 may settle or not at all under Windows Vista and newer due to Windows
> bug where Windows doesn't accept small tick adjustments. See my the link in my other post.
> Also, *under Windows* the offset usually *increases* if you let the polling interval ramp up. See
> http://people.ntp.org/burnicki/windows/ntpd-4.2.7-Win7-poll4-max.pdf
> where the polling interval is allowed to be ramped up, versus
> http://people.ntp.org/burnicki/windows/ntpd-4.2.7-Win7-poll4-6.pdf
> where the polling interval is limited to 6.

Never had a problem keeping within a few ms offset from UTC with
only good network sources, Windows 7 x64, and NTP 4.2.6p5 stable.
With the same platform plus a Garmin 18x LVC, stays within
+/-60us offset, average +/-0.5us, s.d. < 15us;
jitter < 50us, average < 20us, s.d. < 5us.

I just noticed my network sources have been unreachable
for more than 36h - may have to restart - and hope my
ISP or their links have not started blocking NTP port 123!

Take care. Thanks, Brian Inglis

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