NTP service, offset increasing after sync
- by Ajay
I have installed Ubuntu 12.10 version on my PC. I am running NTP service having NTP server as GPS.
I found that when we start NTP service by ntp start command, PC is able to sync with GPS as i get '*' symbol before GPS IP when i run ntpq -p command.
This remains good for some time and then the * symbol is removed which means that PC is not synchronized to that server. Now, by running command ntpq -p it shows that all parameter are OK but as '*' is removed, slowly offset goes on increasing.
remote refid st t when poll reach delay offset jitter
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*192.168.100.33 .GPS. 1 u 7 16 1 2.333 23.799 0.808
remote refid st t when poll reach delay offset jitter
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*192.168.100.33 .GPS. 1 u 14 16 3 2.333 23.799 0.879
remote refid st t when poll reach delay offset jitter
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*192.168.100.33 .GPS. 1 u 11 16 7 2.333 23.799 1.500
remote refid st t when poll reach delay offset jitter
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*192.168.100.33 .GPS. 1 u 8 16 17 2.333 23.799 2.177
below are the last 4 ntp status when sync is lost with GPS
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192.168.100.33 .GPS. 1 u 1 16 377 2.404 1169.94 1.735
remote refid st t when poll reach delay offset jitter
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192.168.100.33 .GPS. 1 u - 16 377 2.513 1171.80 0.898
remote refid st t when poll reach delay offset jitter
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192.168.100.33 .GPS. 1 u 15 16 377 2.513 1171.80 0.898
Since, GPS is already available, PC never re-synchronize itself to GPS later ON. I have to restart the ntp service and then PC synchronizes to GPS and '*' symbol arrives.