[ntp:questions] Re: Reference Clock Insane?

Wolfgang S. Rupprecht wolfgang+gnus20041009T220230 at dailyplanet.dontspam.wsrcc.com
Sun Oct 10 05:27:17 UTC 2004


"Richard B. Gilbert" <rgilbert88 at comcast.net> writes:
> My Motorola Oncore M12 reference clock has been declared insane by
> ntpd!  It appears to be ~228 milliseconds fast with respect to all of
> the network servers!
> 
> What could cause this?

A big ol' pigeon sitting on your roof antenna?  ;-)

What is funny about your 228ms number, is it is pretty close to when
the @Ha makes it into my system.  Just as a sanity check I timestamp
when the @Ha gets received and validated.  It is about 200ms past the
second.  From an old logfile where ntpd was not slaved to a local GPS:

        serial timestamp     PPS timestamp   
        tail end of @Ha

        1037674801.201144 1037674801.000941515
        1037674813.201476 1037674813.000679255
        1037674816.201519 1037674816.000863791
        1037674830.201930 1037674830.000724435
        1037674848.202471 1037674848.000831127
        1037674924.197599 1037674924.000503898
        1037674925.197581 1037674925.000565410
        1037674928.197743 1037674928.000749826
        1037674937.197495 1037674937.000303268
        1037674945.197897 1037674945.000795126
        1037674947.197127 1037674947.000918031
        1037674949.197199 1037674949.000041008
        1037674955.197624 1037674955.000409842
        1037674958.198316 1037674958.000594378
        1037674964.198004 1037674964.000963211

Might the PPS line have gotten really noisy or something so that there
was always a recent transition on it and ntpd just happened to have
looked 228ms past the second?

-wolfgang
-- 
Wolfgang S. Rupprecht                http://www.wsrcc.com/wolfgang/



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