[ntp:questions] ntp execution starts two processes?

Joshua Coombs jcoombs at gwi.net
Thu Mar 17 17:50:11 UTC 2005


>>  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.

Joshua Coombs 





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