From owner-freebsd-net@FreeBSD.ORG  Fri Jul 13 17:28:35 2007
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
X-Original-To: freebsd-net@freebsd.org
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 7EEE116A4B3
	for <freebsd-net@freebsd.org>; Fri, 13 Jul 2007 17:28:35 +0000 (UTC)
	(envelope-from julian@elischer.org)
Received: from outI.internet-mail-service.net (outI.internet-mail-service.net
	[216.240.47.232])
	by mx1.freebsd.org (Postfix) with ESMTP id 8B8D913C526
	for <freebsd-net@freebsd.org>; Fri, 13 Jul 2007 17:28:34 +0000 (UTC)
	(envelope-from julian@elischer.org)
Received: from mx0.idiom.com (HELO idiom.com) (216.240.32.160)
	by out.internet-mail-service.net (qpsmtpd/0.32) with ESMTP;
	Fri, 13 Jul 2007 10:28:34 -0700
Received: from julian-mac.elischer.org (nat.ironport.com [63.251.108.100])
	by idiom.com (Postfix) with ESMTP id CA9DE125B1C;
	Fri, 13 Jul 2007 10:28:33 -0700 (PDT)
Message-ID: <4697B653.8050906@elischer.org>
Date: Fri, 13 Jul 2007 10:28:51 -0700
From: Julian Elischer <julian@elischer.org>
User-Agent: Thunderbird 2.0.0.4 (Macintosh/20070604)
MIME-Version: 1.0
To: Bill Moran <wmoran@collaborativefusion.com>
References: <46967C5C.5040505@seclark.us>
	<469772DA.1000700@gmail.com>	<46977741.8090301@seclark.us>	<20070713093408.b8a92c23.wmoran@collaborativefusion.com>	<4697A60C.4090409@seclark.us>
	<20070713130402.ed2f79ce.wmoran@collaborativefusion.com>
In-Reply-To: <20070713130402.ed2f79ce.wmoran@collaborativefusion.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: Stephen.Clark@seclark.us, Sten Daniel Soersdal <netslists@gmail.com>,
	freebsd-net@freebsd.org
Subject: Re: 6.2 mtu now limits size of incomming packet
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.5
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: Fri, 13 Jul 2007 17:28:35 -0000

Bill Moran wrote:
ractices are
> still evolving.
> 
> Let's flip the question around a bit: why would you _want_ the TCP stack
> to accept frames larger than the stated MTU?
> 

Because mtu is mTu not mRu.
The interface should theoretically always accept any packet up to
the maximum practical size..

As the original BSD group always said.. (from my memories of Kirk's and
Mike's talks in 1991),

"Transmit strictly [according to the spec] but receive forgivingly".

The ability to receive packets larger than mtu was not accidental.
This should be fixed, if it is, as is suggested, a deliberate change.