From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [Bugme-new] [Bug 9270] New: sunhme requires lower MTU to handle 802.1q frames Date: Wed, 31 Oct 2007 15:43:01 -0700 Message-ID: <20071031154301.3cc0fbb9.akpm@linux-foundation.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: bugme-daemon@bugzilla.kernel.org, dev-null@telus.net To: netdev@vger.kernel.org Return-path: Received: from smtp2.linux-foundation.org ([207.189.120.14]:42462 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760765AbXJaWnR (ORCPT ); Wed, 31 Oct 2007 18:43:17 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 31 Oct 2007 14:54:06 -0700 (PDT) bugme-daemon@bugzilla.kernel.org wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=9270 > > Summary: sunhme requires lower MTU to handle 802.1q frames > Product: Drivers > Version: 2.5 > KernelVersion: 2.6.18-3 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Network > AssignedTo: jgarzik@pobox.com > ReportedBy: dev-null@telus.net > > > Most recent kernel where this bug did not occur: N/A > Distribution: Debian 4.0r1 (Etch) > Hardware Environment: Sun Netra T1 105 > Software Environment: > Problem Description: > sunhme requires lower MTU to handle 802.1q frames - even though the PCI > driver supported VLAN tagging, you cannot do full MTU @ 1500 because the > driver doesn't set the card to transfer more the extra bytes for a 802.1q > frame at 1500 MTU. > > Steps to reproduce: > modprobe 8021q > modprobe sunhme > ifconfig eth0 up > vconfig set_name_type DEV_PLUS_VID_NO_PAD > vconfig add eth0 10 > ifconfig eth0.10 192.l68.0.1 netmask 255.255.255.252 broadcast 192.168.0.3 up > # IP pkt size = 1496, Ethernet frame size = 1514 > ping -s 1468 -c 1 -w 1 192.168.0.2 > # IP pkt size = 1500, Ethernet frame size = 1518 > ping -s 1472 -c 1 -w 1 192.168.0.2