From owner-freebsd-hackers@FreeBSD.ORG  Sun Feb  8 09:31:46 2009
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id E53321065672;
	Sun,  8 Feb 2009 09:31:46 +0000 (UTC)
	(envelope-from danny@cs.huji.ac.il)
Received: from kabab.cs.huji.ac.il (kabab.cs.huji.ac.il [132.65.16.84])
	by mx1.freebsd.org (Postfix) with ESMTP id 9AEE08FC18;
	Sun,  8 Feb 2009 09:31:46 +0000 (UTC)
	(envelope-from danny@cs.huji.ac.il)
Received: from pampa.cs.huji.ac.il ([132.65.80.32])
	by kabab.cs.huji.ac.il with esmtp
	id 1LW60v-0000zC-B2; Sun, 08 Feb 2009 11:31:45 +0200
X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2
To: Peter Jeremy <peter@vk2pj.dyndns.org>
In-reply-to: <20090208091656.GA31876@test71.vk2pj.dyndns.org> 
References: <E1LW5Ht-0000VH-D8@kabab.cs.huji.ac.il> 
	<20090208091656.GA31876@test71.vk2pj.dyndns.org>
Comments: In-reply-to Peter Jeremy <peter@vk2pj.dyndns.org>
	message dated "Sun, 08 Feb 2009 20:16:56 +1100."
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Sun, 08 Feb 2009 11:31:45 +0200
From: Danny Braniss <danny@cs.huji.ac.il>
Message-ID: <E1LW60v-0000zC-B2@kabab.cs.huji.ac.il>
Cc: hackers@freebsd.org, freebsd-stable@freebsd.org
Subject: Re: impossible packet length ... 
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 08 Feb 2009 09:31:47 -0000

> 
> --jI8keyz6grp/JLjh
> Content-Type: text/plain; charset=us-ascii
> Content-Disposition: inline
> Content-Transfer-Encoding: quoted-printable
> 
> On 2009-Feb-08 10:45:13 +0200, Danny Braniss <danny@cs.huji.ac.il> wrote:
> >Feb  6 18:00:13 warhol-00.cs.huji.ac.il kernel: bce0: discard frame w/o=20
> >leading ethernet header (len 0 pkt len 0)
> =2E..
> >Feb  6 19:00:00 warhol-00.cs.huji.ac.il amd[715]: Unknown $ sequence in=20
> >"rhost:=3D${RHOST};type:=3Dnfsl;fs:=3D${FS};rfs:=3D$huldig<C0>#^ZM-^KoM- a=
> base"
> >Feb  6 19:00:00 warhol-00.cs.huji.ac.il kernel: impossible packet length=
> =20
> >(2068989523) from nfs server sunfire:/dist
> >
> >which seems to point fingers at bce...
> 
> It does rather suggest that bce is not behaving.  What happens if you
> turn off checksum off-loading?  This should make the kernel drop the
> corrupt packets instead of trying to process them.  If practical, you
> could also try (temporarily) plugging in a different NIC.
> 
I have, and now it's a matter of waiting...
Q: with rxcsum on, and a bad checksum packet is received, is it
   dropped by the NIC? if not, then it somewhat explains the behaviour

changing the nic is tough, but if needed will be done. 
	danny

> Peter Jeremy