From owner-freebsd-stable  Fri Feb  1  7:51:25 2002
Delivered-To: freebsd-stable@freebsd.org
Received: from whizzo.transsys.com (whizzo.TransSys.COM [144.202.42.10])
	by hub.freebsd.org (Postfix) with ESMTP
	id 543ED37B428; Fri,  1 Feb 2002 07:51:10 -0800 (PST)
Received: from whizzo.transsys.com (#6@localhost.transsys.com [127.0.0.1])
	by whizzo.transsys.com (8.11.6/8.11.6) with ESMTP id g11Forp17319;
	Fri, 1 Feb 2002 10:50:53 -0500 (EST)
	(envelope-from louie@whizzo.transsys.com)
Message-Id: <200202011550.g11Forp17319@whizzo.transsys.com>
X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4
To: Michael Sierchio <kudzu@tenebras.com>
Cc: Alexey Luckyanchikov <alexl@alkar.net>,
	freebsd-stable@FreeBSD.ORG, freebsd-net@FreeBSD.ORG
X-Image-URL: http://www.transsys.com/louie/images/louie-mail.jpg
From: "Louis A. Mamakos" <louie@TransSys.COM>
Subject: Re: Weird path MTU autodiscovery problem in 4.5-RELEASE 
References: <20020201125326.GA3036@alkar.net> <3C5AB477.3000304@tenebras.com> 
In-reply-to: Your message of "Fri, 01 Feb 2002 07:29:59 PST."
             <3C5AB477.3000304@tenebras.com> 
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Fri, 01 Feb 2002 10:50:53 -0500
Sender: owner-freebsd-stable@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-stable.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-stable>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-stable>
X-Loop: FreeBSD.ORG


Is the server filtering out ICMP traffic with ipfw or something?

> Alexey Luckyanchikov wrote:
> 
> 
> > 14:06:48.477578 server.7 > client.1371: . 1437:2897(1460) ack 10001 win 65535 (DF) (ttl 64, id 25428, len 1500)
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > Server send packet with size 1500 bytes
> > 
> > 14:06:48.682558 router > server: icmp: client unreachable - need to frag (mtu 1476) for server.7 > client.1371: [|tcp] (DF) (ttl 61, id 25428, len 1500) (ttl 253, id 2491, len 56)
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > Router say to server that he must to decrease packet size
> > 
> > 14:07:04.477857 server.7 > client.1371: . 1437:2897(1460) ack 10001 win 65535 (DF) (ttl 64, id 52781, len 1500)
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > But server ignore this information and still send 1500 bytes packets
> 
> 
> What's the result of 'sysctl net.inet.tcp.path_mtu_discovery'  ??  Not that
> I can imagine, at the moment, what would set it to 0....
> 
> 
> To Unsubscribe: send mail to majordomo@FreeBSD.org
> with "unsubscribe freebsd-stable" in the body of the message


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