[ntp:questions] systems won't synchronize no matter what

David Lord snews at lordynet.org
Sat Oct 30 09:44:29 UTC 2010

David J Taylor wrote:
>> This is a FreeBSD documentation and FreeBSD comes with a pretty good
>> default ntp.conf, much like several of you have suggested.
>> You can find it
>> at:http://www.freebsd.org/cgi/cvsweb.cgi/src/etc/ntp.conf?rev=;content-type=text%2Fx-cvsweb-markup 
>> It has mostly comments with just a set of 3 (yeah, I know) pool systems.
>> -- 
>> R. Kevin Oberman, Network Engineer
> Kevin,
> Yes, I must have edited a file like that when I set up my own FreeBSD 
> system.  I would take issue with:
> - no drift file appears to be specified (although it is mentioned) - I had:
>  driftfile /var/db/ntp.drift
> - why add  maxpoll 9 to all the servers?  That seems wrong.  I see the 
> note: "The option `maxpoll 9' is used to prevent PLL/FLL flipping on 
> FreeBSD.".  So is that a FreeBSD specific issue, and if so, why not fix 
> it in the OS?

You've hit on why it's difficult to have a generic ntp.conf.
It's not just ntpd version specific but operating system version

I swapped my NetBSD systems to FreeBSD after NetBSD-1.6x as I
couldn't get NetBSD-2 to work on my hardware. I swapped back
to NetBSD-3.x when I had hardware compatibility problems with

The default NetBSD ntp.conf for NetBSD 3.1 4.x and 5.1_RC4
are same:

pidfile    /var/run/ntpd.pid
driftfile  /var/db/ntp.drift
logconfig  -syncstatus
tos        minsane 2
server     0.pool.ntp.org
server     1.pool.ntp.org
server     2.pool.ntp.org

My own ntp.conf has restrict lines to allow config from
certain IP addresses and statistics logging enabled.

Local peers have 'minpoll 6 maxpoll 8 iburst' and are back
in sync within about five minutes from a restart. If all
peers are down, as a few weeks back when there was a BT
MSO, it was more like an hour before ntp was ticking again
(I need another couple of radioclocks to cover for this).

Remote servers have 'minpoll 9 maxpoll 11' except from
ISPs I use which have shorter minpoll and 'iburst'.


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