From owner-freebsd-questions  Wed Dec 12 20:52:14 2001
Delivered-To: freebsd-questions@freebsd.org
Received: from tomts7-srv.bellnexxia.net (tomts7.bellnexxia.net [209.226.175.40])
	by hub.freebsd.org (Postfix) with ESMTP id A291C37B405
	for <freebsd-questions@FreeBSD.ORG>; Wed, 12 Dec 2001 20:52:09 -0800 (PST)
Received: from khan.anarcat.dyndns.org ([65.94.189.35])
          by tomts7-srv.bellnexxia.net
          (InterMail vM.4.01.03.16 201-229-121-116-20010115) with ESMTP
          id <20011213045203.KGRX15232.tomts7-srv.bellnexxia.net@khan.anarcat.dyndns.org>;
          Wed, 12 Dec 2001 23:52:03 -0500
Received: from anarcat.dyndns.org (shall.anarcat.dyndns.org [192.168.0.1])
	by khan.anarcat.dyndns.org (Postfix) with ESMTP
	id 64D8B18C9; Wed, 12 Dec 2001 23:52:04 -0500 (EST)
Message-ID: <3C183454.2000105@anarcat.dyndns.org>
Date: Wed, 12 Dec 2001 23:53:40 -0500
From: The Anarcat <anarcat@anarcat.dyndns.org>
User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9.6) Gecko/20011120
X-Accept-Language: fr-CA,fr,en
MIME-Version: 1.0
To: Kevin Oberman <oberman@es.net>
Cc: devin-freebsdquestions@rintrah.org, freebsd-questions@FreeBSD.ORG
Subject: Re: ntpdate works, ntpd does not
References: <200112121946.fBCJkRd11801@ptavv.es.net>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
Sender: owner-freebsd-questions@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-questions.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-questions>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-questions>
X-Loop: FreeBSD.ORG



Kevin Oberman wrote:

>>Date: Wed, 12 Dec 2001 12:39:46 -0500
>>From: devin-freebsdquestions@rintrah.org
>>Sender: owner-freebsd-questions@FreeBSD.ORG
>>
>>I believe ntpd will poll the server over a period of some time to get a feel
>>for drift. I know when I set it up it took several hours before it would
>>adjust the clock. How long are you waiting before you expect ntpd to make adjustments?
> 
> More specifically, it polls once every 64 seconds it has enough
> samples to be statistically significant. This usually takes 5
> samples. It then starts drifting the clock, if needed.


So that's what.. around 5'20"?

> To watch this happen, use the command "ntpq -p". When a server is
> tagged with a symbol, it's considered for use. The one marked '*' is
> the one being used and those marked '+' are also considered "good".


Ok. Let's take it from here:

[sorry, darn mozilla autofills everything...]

su-2.05# ntpq -p && date && ps jax -o start | grep ntpd\ -p
      remote           refid      st t when poll reach   delay   offset 
jitter
==============================================================================
  time.nist.gov   0.0.0.0         16 u    -   64    0    0.000    0.000 
4000.00
Wed Dec 12 23:37:15 EST 2001
root      4593     1  4593 c06ef9c0    0 S<s   ??    0:00.74 ntpd -p 
/var/run 11:27PM
root      4680  4465  4679 c076a2c0    2 R+    p0    0:00.05 grep ntpd 
-p     11:37PM

so ntpd was started at 11:27PM, 10 minutes before the command was ran, 
and the character before the hostname is " ". This means, from the man page:

        space   (reject) The peer is discarded as unreachable, synchro-
                nized to this server (synch loop) or outrageous synchro-
                nization distance.

So ntpd does reject the host. Maybe it's the synch loop thing I can't 
figure out though..

One thing I read from the tcpdump output I found strange, though.. It 
sends a packet containing a "stratum 0" instruction, somehow. Maybe it's 
related?

The ntpdc "peers" command leads to a different result, surprisingly. 
Indeed, it seems the character codes are different between ntpq and ntpdc:

ntpdc> peers
      remote           local      st poll reach  delay   offset    disp
=======================================================================
=time.nist.gov   5.0.0.0         16   64    0 0.00000  0.000000 0.00000

ntpdc(8):
...
              a "=" means the remote server is being polled
              in client mode,
...

And, BTW, the more I wait, the more the "unreach" counter from the 
ntpdc(8) "peers" command increments.


> IF the source and the sync to the local system are stable, the time
> between polls will increase to 1024 seconds between polls.
> 
> R. Kevin Oberman, Network Engineer
> Energy Sciences Network (ESnet)
> Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
> E-mail: oberman@es.net			Phone: +1 510 486-8634


Thanks,

A.

 



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message