[ntp:questions] Using ntpdate -b SERVER shortly after SERVER boots

Steve Kostecke kostecke at ntp.isc.org
Mon Feb 12 14:12:49 UTC 2007


On 2007-02-10, Donald Murray, P.Eng. <donaldm314 at gmail.com> wrote:

> Okay, I've added iburst to the SERVER as follows:
> server  127.127.1.0 iburst      # local clock

iburst has _NO_ effect on ref-clocks (including 127.127.1.x).

> It still takes 3 minutes or longer for 'ntpdate -B SERVER' to succeed.

That's because ntpd has to poll 127.127.1.0 until enough data is
collected. This usually takes 4 polls (i.e. 3 * minpoll).

> Unless anyone has some other suggestions,

You could use 'server 127.127.1.0 minpoll 2' to reduce the default poll
interval to 16 seconds. So the initial sync time would be reduced to 3 *
16 seconds, or 48 seconds. On my ntp-4.2.2 test system this consistently
produced an intial "LocalCLK sync" of between 50 and 53 seconds.

I don't believe that you'll do better without patching ntpd.

BTW: The use of minpoll _may_ have some side effects.

> it looks like I'm going to have to use /bin/date...
>
> More details on power for the curious. These are drilling rigs and all
> "power" comes from generators.

If you can access these systems to modify the configuration files you
should be able to drop in a modified ntpd.

-- 
Steve Kostecke <kostecke at ntp.isc.org>
NTP Public Services Project - http://ntp.isc.org/




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