[ntp:questions] Windows time question.

Chuck Swiger cswiger at mac.com
Fri Apr 22 17:08:22 UTC 2011

On Apr 22, 2011, at 8:22 AM, unruh wrote:
>> The pool DNS lookup now returns 3 servers, used to be 5.
>> When everyone uses 10 servers the load on the pool as a whole is
>> twice what it would need to be, and 3 times what would be the minimum
>> reasonable value.
> I agree. It is absurd. It seems to indicate that the ntp folk really
> really do not trust the pool, and figure that if you get fewer than 10, you have a
> reasonable chance that a majority will deliver bad time. Ie, they appear
> to feel that the pool is a pretty useless souce of time. 

The pool performs scorekeeping upon the quality of time served by pool members, available under http://www.pool.ntp.org/scores/${IP}, and will not vend IPs which are serving badly wrong time.

As for the # of timeservers being used, polling ten timeservers at a default poll interval of 1024 seconds is less traffic then beating on one timeserver every minute -- aka 64 second poll, and considered "borderline" to genuinely abusive polling rates.

Regular NTP traffic isn't a problem, and even if doubled wouldn't be too bad, IMHO; but abusive traffic is already a real problem.  Even so, I suspect that most NTP pool providers would prefer that the default number of pool servers used would be 4 or 5, not ten....


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