[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 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 until enough data is
collected. This usually takes 4 polls (i.e. 3 * minpoll).

> Unless anyone has some other suggestions,

You could use 'server 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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