[ntp:questions] Differences in behaviour of ntpd 4.1.1 and 4.2.0 on Windows XP
neil.burn at marconiselenia.com
Thu Nov 20 17:00:03 UTC 2003
I am a little confused over the differences in behaviour of ntpd 4.1.1
and 4.2.0 on Windows XP.
I have an acutime 2000 connected to a PC running ntp. I am
comparing the offset between the acutime pps output and the pc time as
shown by an oscilloscope with the offset as reported by "ntpq -c pe".
With 4.2.0 the offset as reported by ntpq tends to zero as expected
but the oscilloscope shows an offset of anything up to 700
milliseconds (this offset value varies each time ntp is restarted).
With 4.1.1 the offset as reported by ntpq agrees with the oscilloscope
to within the millisecond.
I've also tried multiple quick succession runs of "ntpd -q -d"
(starting each run as soon as the previous run had completed). For
4.1.1, ntpd consistently sets the time to within a millisecond but for
4.2.0 the time is anything up to hundreds of milliseconds out.
For ntpd 4.2.0, I got the following results running ntpd -q -d:
Run 1: ntpd: time set -0.733359s
Run 2: ntpd: time set -0.534999s
Run 3: ntpd: time set +0.239927s
Run 4: ntpd: time set -0.660884s
For all of these runs the oscilloscope showed offsets of hundreds of
milliseconds between the PPS output and PC time.
For ntpd 4.1.1, I got the following results running ntpd -q -d:
Run 1: ntpd: time set +0.726997s
Run 2: ntpd: time slew +0.000553s
Run 3: ntpd: time slew +0.000365s
Run 4: ntpd: time slew +0.000215s
For all of these runs the oscilloscope showed an offset between the
PPS output and the PC time of within 1 millisecond.
My ntp.conf file is basically:
tinker panic 0 huffpuff 3600
server 127.127.29.1 burst iburst
Is there anything specific to 4.2.0 I should be adding to the config
file to get it to perform as well as 4.1.1?
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