[ntp:questions] Re: Windows timekeeping - sudden degradation - why?

Richard B. Gilbert rgilbert88 at comcast.net
Sat Dec 10 15:41:59 UTC 2005


John Allen wrote:

>
>> I'm not an expert in reading those "rv" outputs, but if you are on 
>> stratum 16 it means you aren't synchronised.  Try the command:  ntpq 
>> -p deeley. The "reach" column should show 377 for each server  - 
>> octal for a bit field of 8 ones meaning 8 good connections.
>>
>> My guess is that you may have a TCP/IP problem, like a firewall 
>> blocking access from your NTP client to its servers.
>
>
> David,
>
> Thanks for the feedback.
>
> First of all, I looked again at your website and I realise that my 
> problem is probably not the same as yours - you had a deterioration in 
> time-keeping, whereas my system seems to have given up altogether. 
> Probably my problem belongs in a separate thread, but I'll keep going 
> here as there is a lot of useful information on Windows and NTP in 
> this thread.
>
> Mine is not an obvious TCP/IP problem: the client (deeley) and server 
> (barlow) are both on the LAN, whereas the only firewall - on barlow - 
> is on the interface to the outside world (and barlow's ntpd 
> synchronizes fine with pool.ntp.org servers). Also there is no sign of 
> trouble with netstat -s.
>
> When looking at the NTP log on deeley after a period of time I see a 
> pattern: it records synchronization to barlow, and then 4-10 minutes 
> later it records "no servers reachable", like this:
>
> 10 Dec 13:54:19 NTP[3548]: synchronized to 192.168.0.5, stratum 3
> 10 Dec 14:00:38 NTP[3548]: no servers reachable
>
> Successive ntpq -p commands show:
>
> C:\NTP>ntpq -p
>      remote           refid      st t when poll reach   delay   
> offset  jitter
> ============================================================================== 
>
> *barlow          213.222.11.219   3 u   37   64   77    0.278  -816.70 
> 861.409
>
> C:\NTP>ntpq -p
>      remote           refid      st t when poll reach   delay   
> offset  jitter
> ============================================================================== 
>
>  barlow          213.222.11.219   3 u   37   64  377    0.267  -28115. 
> 1823.41
>
> I'm open to any suggestions for looking at other debugging information.
>
> John
>
> -- 
>
> John Allen
> Bofferdange, Luxembourg
> allen{at}vo{dot}lu
> http://www.homepages.lu/allen

Do you have a drift file?   What value is stored in the drift file?   
What was the interval between the two ntpq -p commands?

My guess would be that your local clock has a frequency error well in 
excess of 500 parts per million!   If that is the case, you will 
probably have to replace the mother board to fix it.




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