[ntp:questions] Re: Time limit for NTP to do timing correction??

David J Taylor david-taylor at invalid.com
Wed Nov 3 09:42:07 UTC 2004


Crystal wrote:
> It is said that there is a limit of the time difference that NTP would
> correct the timing between the server and client. That is, if the time
> difference is more than the limit, NTP would just stop its service and
> quit without doing any time correction. Any one knows what is this
> limit for NTP Release 4 (for Microsoft Windows NT) ? And, how to
> change this limit? Cheers :>

An offset of greater 1000 seconds is one limit.

A clock error of greater than 500 ppm (parts per million) is another 
limit.

I believe that with too great an offset NTP won't start, and with too 
great an error NTP won't work as intended (it may give step changes in the 
clock, I'm not sure).

I believe the 500ppm limit is hard coded.  If you are seeing the 1000 
second limit, perhaps you do not have your computer time zone correctly 
set?  NTP works in UTC, as does the internal clock in Windows NT.  The 
Time Zone offset affects how the clock is displayed to the users.  The 
BIOS clock works in local time!

I hope some of this helps.

Cheers,
David 





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