[ntp:questions] NNTP server causing large jumps in time

Steve Kostecke kostecke at ntp.org
Thu May 1 17:42:29 UTC 2008


On 2008-05-01, Dave <foo at coo.com> wrote:

> Looking at the logs on my Sun Blade 2000 running Solaris 10, I see 
> numerous occasions on which the time has been stepped. Looking at the 
> few only (today, 1/5/2008), I see it was stepped around +0.3 sec at 3 
> AM, then -0.4 at 4:30 am, then half an hour later at 5am it was moved 
> -0.6 sec, then 40 minutes later it is moved another -0.6 sec. Since then 
> (its now 1:30 pm), it has not changed.

Random jumps like this can be caused by clock hopping.

> My config file is below. I'm not sure if I would be better picking time 
> servers close to me.
>
>
> # ident "@(#)ntp.server 1.6     00/07/17 SMI"
> #
> # /etc/inet/ntp.server
> #
> # An example file that could be copied over to /etc/inet/ntp.conf and

BTW: The comment lines (the ones which start with '#') made your article
unnecessarily difficult to read.

> server navobs1.oar.net
> server utcnist.colorado.edu
> server gnomon.cc.columbia.edu
> server ntp.colby.edu
> server clepsydra.dec.com
> server chronos.cru.fr
> server ptbtime1.ptb.de
> server ntp.metas.ch

I'd start by selecting the nearest server to you and using just that.
You should quickly be able to see if this cures your random time jumps.

When it is time to add more time servers, you'll have to decide if the
pool is "good enough" for your purposes.

> broadcast 224.0.1.1 ttl 0

Are you actually operating a multicast server?

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




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