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Date:      Sun, 17 Sep 1995 23:05:25 +0200
From:      mal@aristotle.algonet.se (Mats Lofkvist)
To:        freebsd-hackers@FreeBSD.org
Subject:   xntpd (or kernel) timekeeping problem?
Message-ID:  <9509172105.AA06482@sophocles.>

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I configured my machine to run xntpd about a month ago (running ~2.0.5).
The error in the system clock frequency was to large for ntp to lock it.
After changing the tickadj args to "-q -t 9995 -a 5" it locked fine with
a drift around 50 ppm. Today I updated all of my binaries (including kernel)
to a fresh 2.1-stable version, and ntp still seems to like the 500 ppm hack
(i.e. the new values in ntp.drift still are around 50 ppm with the tickadj
args above).

Is this a problem in xntpd or the kernel? It is a bit suspicius that hacking
tickadj exactly one tick makes the drift very low...

(I'm running it on a 486DX4/100 with a 28.8kbit cslip connection to my
 internet provider. Info from xntpdc (still with the -t 9995):

 xntpdc> sysinfo
 system peer:          Stockholm-DGIX.sunet.se
 system peer mode:     client
 leap indicator:       00
 stratum:              4
 precision:            -17
 root distance:        0.45340 s
 root dispersion:      0.05278 s
 reference ID:         [194.68.128.19]
 reference time:       b4070811.aa9e5000  Sun, Sep 17 1995 22:48:17.666
 system flags:         pll monitor stats 
 frequency:            0.000 ppm
 stability:            12.300 ppm
 broadcastdelay:       0.003906 s
 authdelay:            0.000122 s
 xntpdc> loopinfo
 offset:               0.018491 s
 frequency:            -31.324 ppm
 poll adjust:          -6
 watchdog timer:       43 s
 xntpdc> pe
      remote           local      st poll reach  delay   offset    disp
 =======================================================================
 *Stockholm-DGIX. 192.9.200.101    3   64  377 0.27216  0.018491 0.01958
 =sunic.sunet.se  192.9.200.101    3   64  377 0.23859 -0.034453 0.02048

 This looks ok to me.)

      _
Mats Lofkvist
mal@algonet.se



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