From owner-freebsd-net@FreeBSD.ORG Fri Sep 7 23:03:27 2007 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F403016A419; Fri, 7 Sep 2007 23:03:26 +0000 (UTC) (envelope-from davidch@broadcom.com) Received: from MMS3.broadcom.com (mms3.broadcom.com [216.31.210.19]) by mx1.freebsd.org (Postfix) with ESMTP id 8AB3213C442; Fri, 7 Sep 2007 23:03:26 +0000 (UTC) (envelope-from davidch@broadcom.com) Received: from [10.10.64.154] by MMS3.broadcom.com with ESMTP (Broadcom SMTP Relay (Email Firewall v6.3.1)); Fri, 07 Sep 2007 16:03:10 -0700 X-Server-Uuid: 20144BB6-FB76-4F11-80B6-E6B2900CA0D7 Received: by mail-irva-10.broadcom.com (Postfix, from userid 47) id 27F772AF; Fri, 7 Sep 2007 16:03:10 -0700 (PDT) Received: from mail-irva-8.broadcom.com (mail-irva-8 [10.10.64.221]) by mail-irva-10.broadcom.com (Postfix) with ESMTP id 136232AE; Fri, 7 Sep 2007 16:03:10 -0700 (PDT) Received: from mail-irva-12.broadcom.com (mail-irva-12.broadcom.com [10.10.64.146]) by mail-irva-8.broadcom.com (MOS 3.7.5a-GA) with ESMTP id FQS41248; Fri, 7 Sep 2007 16:03:09 -0700 (PDT) Received: from NT-IRVA-0750.brcm.ad.broadcom.com ( nt-irva-0750.brcm.ad.broadcom.com [10.8.194.64]) by mail-irva-12.broadcom.com (Postfix) with ESMTP id D6BD169CA4; Fri, 7 Sep 2007 16:03:08 -0700 (PDT) X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Date: Fri, 7 Sep 2007 16:03:07 -0700 Message-ID: <09BFF2FA5EAB4A45B6655E151BBDD903051CBFCB@NT-IRVA-0750.brcm.ad.broadcom.com> In-Reply-To: <20070907230049.GG87451@elvis.mu.org> Thread-Topic: FreeBSD discarding received packets > MTU Thread-Index: AcfxovRyX5hKnh4nR1SVG9kM5YnoMwAADpoQ References: <46E0632D.8070200@elischer.org> <46E07E74.5020204@elischer.org> <09BFF2FA5EAB4A45B6655E151BBDD9030501D5C0@NT-IRVA-0750.brcm.ad.broadcom.com> <46E0A5DB.3080404@elischer.org> <09BFF2FA5EAB4A45B6655E151BBDD903051CBEB6@NT-IRVA-0750.brcm.ad.broadcom.com> <20070907194749.GD87451@elvis.mu.org> <09BFF2FA5EAB4A45B6655E151BBDD903051CBF54@NT-IRVA-0750.brcm.ad.broadcom.com> <20070907230049.GG87451@elvis.mu.org> From: "David Christensen" To: "Alfred Perlstein" X-WSS-ID: 6AFF07246B094959-01-01 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Cc: FreeBSD Net , Julian Elischer Subject: RE: FreeBSD discarding received packets > MTU X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Sep 2007 23:03:27 -0000 > > > Internet ettiquette demands being gracious in what you accept. > > > The default policy of FreeBSD is to accept such packets. > > > This is a really weird bug to track down. > > > Other drivers support it. > > >=20 > > > This isn't worth making a stand over, unless you're trying > > > to hold users of YOUR driver hostage. > > >=20 > >=20 > > I'm just being cautious about making changes before I understand > > all of the implications. The driver's current behavior is > > supported by IEEE 802.3 specification (802.3-2005, 4.2.4.2.1) > > and is implemented in the same way for other operating systems > > that are very widely deployed (including Windows and Linux) > > without any reported problems. The existing bge driver which > > was developed for FreeBSD 10 years ago also operates this way, > > so all of my references for porting this driver happen to agree > > on the same implementation. >=20 > Which is all well and good, but the age of a bug does not a feature > make. >=20 > Please think of the four points I raised. >=20 > I think it makes sense to possibly add a "enforce rx mtu" knob > somewhere, but it should likely be turned off. That's the plan. Dave