[ntp:questions] Re: Question on abusive clients.

David L. Mills mills at udel.edu
Mon Dec 26 19:00:29 UTC 2005


David,

You have forced the poll interval and time constant to 64 s. Should that 
source fail and the host switch to another source with poll interval 
clamped to 1024 s, the discipline loop is seriously undersampled and 
could well become unstable.

Dave

David J Taylor wrote:

> Richard B. Gilbert wrote:
> 
>>David J Taylor wrote:
>>
>>
>>>Richard B. Gilbert wrote:
>>>[]
>>>
>>>
>>>
>>>>The reference implementation of ntpd contributes to the deluge in a
>>>>small way!   Running a Motorola Oncore as a reference clock causes
>>>>my home server to query its internet servers every 16 seconds.  It's
>>>>nothing I would do by choice; they serve only as a sanity check on
>>>>my Oncore reference clock   There does not appear to be any way of
>>>>turning this feature off short of modifying the code.
>>>>
>>>>
>>>
>>>Agreed.  I would like to have my client PCs poll their two LAN
>>>servers at 64s and one Internet server at 1024s (also as a sanity
>>>check), but it seems that if any LAN server is set to 64s the
>>>Internet servers are also polled at 64s intervals.
>>>
>>>David
>>>
>>>
>>>
>>>
>>
>>Does that happen even if you specify MINPOLL=10 for the internet
>>servers?
> 
> 
> No, it does not, so I've altered my configuration to have minpoll=10 for 
> the backup Internet servers.
> 
> Thanks for the suggestion!
> 
> David 
> 
> 




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