From owner-freebsd-net@FreeBSD.ORG Sat Jan 7 02:35:01 2006 Return-Path: X-Original-To: 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 788BE16A41F for ; Sat, 7 Jan 2006 02:35:01 +0000 (GMT) (envelope-from kamal_ckk@yahoo.com) Received: from web30001.mail.mud.yahoo.com (web30001.mail.mud.yahoo.com [68.142.200.64]) by mx1.FreeBSD.org (Postfix) with SMTP id 0779843D46 for ; Sat, 7 Jan 2006 02:35:00 +0000 (GMT) (envelope-from kamal_ckk@yahoo.com) Received: (qmail 68516 invoked by uid 60001); 7 Jan 2006 02:35:00 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=XPoy8LSesbaPNbFUABieY5CnCZ4/eHdei6IMPKj21BOW3bChVag9u0HpSMWJ56nUGiq6Yd1kORzgyK3NneaHwJUcEoaErz+HEszBi8avBcqzE3ClBXxxJbaLud25XE3W1L/KUiJBJ8IkzD2X0HNVFuoRRvtFJPlA4b3b5v/ysoY= ; Message-ID: <20060107023500.68514.qmail@web30001.mail.mud.yahoo.com> Received: from [202.79.62.13] by web30001.mail.mud.yahoo.com via HTTP; Fri, 06 Jan 2006 18:35:00 PST Date: Fri, 6 Jan 2006 18:35:00 -0800 (PST) From: kamal kc To: freebsd In-Reply-To: <20060106234511.GY826@overlord.e-gerbil.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Subject: Re: increasing the ethernet MTU greater than 1500 (1502) 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: Sat, 07 Jan 2006 02:35:01 -0000 --- Richard A Steenbergen wrote: > On Fri, Jan 06, 2006 at 10:02:07AM -0800, John-Mark > Gurney wrote: > > Nope, for pre-gige, only 1500 MTU is supported... > This was extended > > slightly to support vlan tagging, but I believe > many of the drivers to > > If you have a good gige card, you can go to 9000 > MTU and beyond... > Technically speaking, the problem was not fixed by > GigE or even 10GigE. > The wonderful folks over at the IEEE feel there is > no need to bring us out > of the ethernet networking dark ages by defining any > kind of standards for > anything > 1500 bytes. We're left with a bunch of > vendors who are each > trying to do the right thing by picking random sizes > ranging from 1518 > (stock + 4 bytes for a single .1q tag) to 16384, but > there are no real > standards, no mechanisms for ensuring > interoperability, no protocols for > negotiating MTUs between networks, etc. Lots of newer FastE cards > support jumbos or some kind > of mini jumbo too. There are still plenty of NICs > and switches out there > with no or very half-ass jumbo support though. thanks for providing the insight. I would try with GigE next time. since it seems a bad option to try MTU larger than 1500 in 10/100 Mbps ethernet i tried another option to solve my problem. Now i don't add additional header(2 bytes) to distinguish the packets that were processed. I rather tried for protocol mapping. This is what i did, i mapped the protocol (in the protocol field of the ip header) 0..56 to 138..194 if compressed 0..56 to 195..251 if uncompressed with this simple protocol mapping i could only compress 57 protocol data. I guess the protocols 138 to 251 will not be used for couple of years. OR Is there any slighest possibility ???? thanks, kamal __________________________________________ Yahoo! DSL – Something to write home about. Just $16.99/mo. or less. dsl.yahoo.com