From owner-freebsd-net@FreeBSD.ORG  Thu Feb 10 21:30:58 2005
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 2E38116A4CE
	for <freebsd-net@freebsd.org>; Thu, 10 Feb 2005 21:30:58 +0000 (GMT)
Received: from web80606.mail.yahoo.com (web80606.mail.yahoo.com
	[66.218.79.95])	by mx1.FreeBSD.org (Postfix) with SMTP id F245243D41
	for <freebsd-net@freebsd.org>; Thu, 10 Feb 2005 21:30:57 +0000 (GMT)
	(envelope-from mohan_srinivasan@yahoo.com)
Message-ID: <20050210213057.96467.qmail@web80606.mail.yahoo.com>
Received: from [64.172.45.63] by web80606.mail.yahoo.com via HTTP;
	Thu, 10 Feb 2005 13:30:57 PST
Date: Thu, 10 Feb 2005 13:30:57 -0800 (PST)
From: Mohan Srinivasan <mohan_srinivasan@yahoo.com>
To: Kris Kennaway <kris@obsecurity.org>, Sam Jansen <sam@meta.net.nz>
In-Reply-To: <20050210212852.GA10195@xor.obsecurity.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
cc: freebsd-net@freebsd.org
Subject: Re: SACK problems
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 10 Feb 2005 21:30:58 -0000

No. That fix is not relevant.

I'll take a look at this in a bit (after I fix the other SACK
issue reported a couple of days ago).

mohan

--- Kris Kennaway <kris@obsecurity.org> wrote:

> On Fri, Feb 11, 2005 at 10:15:35AM +1300, Sam Jansen wrote:
> > During some testing on an isolated network we have, I found some 
> > interesting behaviour from a FreeBSD 5.3 host using TCP SACK.
> > 
> > I've detailed this problem fully at:
> > 
> >    http://www.wand.net.nz/~stj2/nsc/emu_freebsd.html
> > 
> > PCAP traces and some screenshots from tcptrace graphs can be found at 
> > the above link to show what is happening. It looks to me like SACK 
> > blocks are being incorrectly generated in this example. I can't think of 
> > any valid reason why a SACK block would SACK from below the current ACK 
> > value to above it (which is the problem here).
> > 
> > Thoughts, anyone? Am I just wrong here and this is valid, expected 
> > behaviour?
> 
> A fix to the SACK code was committed yesterday, which may or may not
> be relevant.
> 
> Kris
> 

> ATTACHMENT part 2 application/pgp-signature