[ntp:questions] ntp execution starts two processes?

Brian Inglis Brian.Inglis at SystematicSW.Invalid
Fri Mar 18 20:40:59 UTC 2005


On Thu, 17 Mar 2005 12:50:11 -0500 in comp.protocols.time.ntp, "Joshua
Coombs" <jcoombs at gwi.net> wrote:

>>>  server ntp.colby.edu            iburst          maxpoll 12
>>>  server ntp0.jensenresearch.com  iburst          maxpoll 12
>>>  server timeserver.cs.umb.edu    iburst          maxpoll 12
>>>  server nist1-ny.glassey.com     iburst          maxpoll 12
>>>  server time.no-such-agency.net  iburst          maxpoll 12
>>
>> Don't set maxpoll unless you know for sure what it does, why you want it, 
>> what the possible risks are, etc....  Your machine may need a lower 
>> maxpoll in order to detect and deal with your clock drift, and if you 
>> force it this high, you may not be able to keep good time.
>
>A couple ntp operators requested I keep my total NTP activity below 500 
>polls a day when I was soliciting permission to use public stratum 1 
>sources.  I will be running 6 to 8 NTP servers, at least 3 of which will be 
>Cisco boxen.  On the Ciscos, I can't tweak poll intervals, so they top out 
>at 1024 seconds, or 85 polls a day.  3 of them use up half of my alloted 
>polls, and I'd prefer not to run close to that limit by not limiting the 
>other boxen.  I opted to allow ntpd to use a longer poll interval on the 
>pc's as I'll have 3 boxen (the ciscos) running tighter poll intervals, and 
>all the systems will be peered together.  Hopefully the pcs will eventually 
>be picking up local stratum 0 time sources, justifying longer external 
>checks on some systems even more.
>
>Observation shows NTP will reign in poll intervals if it isn't confidant, so 
>as long as the box shows on the bench it's clock is stable over time, I'm 
>comfortable with this setup and aware of the risks I'm setting myself up 
>for.

Might it not be more useful to just run your Cisco boxes at stratum 3,
synchronized by your stratum 2 PC servers which can then run ntpd
within its design limits; or only access the *limited* public stratum
1 servers from whichever of your stratum 2 PC servers *are* dedicated
to timekeeping. Cisco boxes are not dedicated timekeepers as that is
not their primary function. 

-- 
Thanks. Take care, Brian Inglis 	Calgary, Alberta, Canada

Brian.Inglis at CSi.com 	(Brian[dot]Inglis{at}SystematicSW[dot]ab[dot]ca)
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