[ntp:questions] Very large jitter and offsets on GPS ref clock after upgrade to "p5"
Chris Albertson
albertson.chris at gmail.com
Fri Jan 6 03:44:36 UTC 2012
I just upgraded to 4.2.6p5 at 1.2349-o and I'm getting some odd results.
NTPD has been running for about 12 hours not on a Linux system. The
following three "peers" displays were taken about one minute apart.
How do I go about debugging this? Where to start? The PPS coming
from the Oncore has less jitter on it than I can measure with an
HP5328 counter. I shows a period of exactly 1,000,000 uSec. I look
at "clockstats" and
ntpq> peers
remote refid st t when poll reach delay offset jitter
==============================================================================
oGPS_ONCORE(0) .GPS. 0 l 14 16 357 0.000 0.004 377.962
+dev.factiondev. 66.220.9.122 2 u 18 64 377 44.131 -1.572 0.515
+bindcat.fhsu.ed 132.163.4.102 2 u 60 64 377 68.404 1.101 0.438
*ntp3.junkemailf 209.81.9.7 2 u 62 64 377 20.440 -1.842 0.862
-tds-solutions.n 167.23.176.214 3 u 17 64 377 45.344 -3.163 1.269
ntpq> peers
remote refid st t when poll reach delay offset jitter
==============================================================================
*GPS_ONCORE(0) .GPS. 0 l 6 16 327 0.000 999.997 999.996
+dev.factiondev. 66.220.9.122 2 u 6 64 377 43.754 -0.970 0.510
-bindcat.fhsu.ed 132.163.4.102 2 u 41 64 377 68.054 1.100 0.680
+ntp3.junkemailf 209.81.9.7 2 u 44 64 377 20.938 -1.328 0.524
-tds-solutions.n 167.23.176.214 3 u 7 64 377 44.084 -2.274 1.075
ntpq> peers
remote refid st t when poll reach delay offset jitter
==============================================================================
*GPS_ONCORE(0) .GPS. 0 l 3 16 277 0.000 -0.003 377.964
+dev.factiondev. 66.220.9.122 2 u 61 64 377 43.754 -0.970 0.510
-bindcat.fhsu.ed 132.163.4.102 2 u 29 64 377 68.054 1.100 0.524
+ntp3.junkemailf 209.81.9.7 2 u 32 64 377 20.938 -1.328 2.476
-tds-solutions.n 167.23.176.214 3 u 62 64 377 44.084 -2.274 1.075
ntpq> ver
ntpq 4.2.6p5 at 1.2349-o Thu Jan 5 07:51:56 UTC 2012 (1)
I know you are going to ask so here are the config files
MODE 4
LAT 33 51 54.315
LONG -118 23 01.782
HT 25.56 M
DELAY 50 NS
ASSERT
SHMEM /var/log/ntpstats/ONCORE
POSN3D
MASK 0
****************************
driftfile /var/lib/ntp/ntp.drift
statsdir /var/log/ntpstats/
logconfig =all
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable
disable auth
# Connect to Oncore UT+ GPS
server 127.127.30.0 prefer
server 0.us.pool.ntp.org
server 1.us.pool.ntp.org
server 2.us.pool.ntp.org
server 3.us.pool.ntp.org
******************************
Chris Albertson
Redondo Beach, California
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