From owner-freebsd-net@FreeBSD.ORG  Fri Jan  2 09:51:12 2004
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 8293616A4CE
	for <net@freebsd.org>; Fri,  2 Jan 2004 09:51:12 -0800 (PST)
Received: from hotmail.com (law10-f64.law10.hotmail.com [64.4.15.64])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 8021443D1D
	for <net@freebsd.org>; Fri,  2 Jan 2004 09:51:11 -0800 (PST)
	(envelope-from segr@hotmail.com)
Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC;
	 Fri, 2 Jan 2004 09:51:11 -0800
Received: from 142.59.20.123 by lw10fd.law10.hotmail.msn.com with HTTP;
	Fri, 02 Jan 2004 17:51:11 GMT
X-Originating-IP: [142.59.20.123]
X-Originating-Email: [segr@hotmail.com]
X-Sender: segr@hotmail.com
From: "Stephane Raimbault" <segr@hotmail.com>
To: kudzu@tenebras.com
Date: Fri, 02 Jan 2004 10:51:11 -0700
Mime-Version: 1.0
Content-Type: text/plain; format=flowed
Message-ID: <LAW10-F64obddQzCjEC00004362@hotmail.com>
X-OriginalArrivalTime: 02 Jan 2004 17:51:11.0420 (UTC)
	FILETIME=[021C27C0:01C3D159]
cc: net@freebsd.org
Subject: Re: VLAN MTU problem in 4.9 ?
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: Fri, 02 Jan 2004 17:51:12 -0000

Anything specific you want me to do while I'm doing the tcpdump?

I looked at the man page for the vlan after you mentioned it... I'm not sure 
if it applies or not... my MTU is set to 1500 by the system for the 
interfaces and vlan's.  I'm pretty sure when I was running 4.9-RC2 it was as 
well but I'm not 100% sure.

Thanks,
Stephane.


>From: Michael Sierchio <kudzu@tenebras.com>
>To: Stephane Raimbault <segr@hotmail.com>
>CC: net@freebsd.org
>Subject: Re: VLAN MTU problem in 4.9 ?
>Date: Fri, 26 Dec 2003 15:15:03 -0800
>
>Stephane Raimbault wrote:
>
>>So it seems that when I specify a ping of greater then 1468 the pings stop 
>>responding to the vlan interface on the freebsd router?
>>
>>I also did a tcpdump while doing these pings from the freebsd router and 
>>it doesn't see any packets when specifying a ping of 1469, but it sees the 
>>ping with pkt size specified to 1468.
>>
>>Any thoughts on this problem that I'm having?  Any other data I can 
>>provider perhaps?
>
>DF?  Size of tagged frames?  Recall that "packet size" perhaps not
>what you think, also.
>
>Have you read the vlan man page, specifically:
>
>      Note: Unless marked as having native support for vlan, the above 
>drivers
>      don't inform the vlan driver about their long frame handling 
>capability.
>      Just increase the MTU of a vlan interface if it appears to be lower 
>than
>      1500 bytes after attaching to a parent known to support long frames.
>
>But you invite speculation -- a raw tcpdump (-nqvv or so) would
>be nice.
>
>

_________________________________________________________________
STOP MORE SPAM with the new MSN 8 and get 2 months FREE*   
http://join.msn.com/?page=dept/bcomm&pgmarket=en-ca&RU=http%3a%2f%2fjoin.msn.com%2f%3fpage%3dmisc%2fspecialoffers%26pgmarket%3den-ca