[ntp:questions] Flash 400 on all peers; can't get ntpd to be happy

Chris Albertson albertson.chris at gmail.com
Sat Mar 12 06:48:14 UTC 2011

On Fri, Mar 11, 2011 at 9:24 PM, Ralph <ralph at depth.net> wrote:
> @Chris
> I appreciate the offer to help.
> I've been thinking about this problem a while and here are my thoughts... It
> seems to me that ntpd has the goal of keeping extremely accurate time - which
>  is important for many obvious reasons.  However there are those of us that
> don't need time accurate to the millisecond and / or don't need time to be
> perfectly in sync with the rest of the world.
> With that in mind, it would be nice if there was something out there that
> operated in a slightly different mode than ntpd does..

You can set that up if you like.  Use either "ntpdate" or "ntpd -q".
They both work the same way.  They go to an NTP server and then jump
the local system time to match the server.   Run this every hour as a
cron job.

There are other even simpler and older time protocols that you can use
rather then ntpdate.  I think "rdate" is the oldest one used on the
Internet with the RFC dated in 1983.  Running rdate is very simple and
light weight.    You call it periodically and it jumps the clock to
roughly match the rdate server.

The trouble with all the simple methods is that that "jump" the clock
to the "correct" time. This means time will run backwards if you clock
was fast.   This is not good at all if yur computer was measuring
time.   NTP is smart in that it never causes a big jump in time and I
thin it is about as simple as can a system that never jumps time can

Chris Albertson
Redondo Beach, California

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