From owner-freebsd-net@FreeBSD.ORG Fri Jan 6 07:18:08 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 8FAF216A41F for ; Fri, 6 Jan 2006 07:18:08 +0000 (GMT) (envelope-from kamal_ckk@yahoo.com) Received: from web30008.mail.mud.yahoo.com (web30008.mail.mud.yahoo.com [68.142.200.71]) by mx1.FreeBSD.org (Postfix) with SMTP id E2FF943D45 for ; Fri, 6 Jan 2006 07:18:07 +0000 (GMT) (envelope-from kamal_ckk@yahoo.com) Received: (qmail 87773 invoked by uid 60001); 6 Jan 2006 07:18:07 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=o1YWOHvxfevcs92RVeOmo77/pYcZpq0nJkomnMHHMTUgl8+wCn4fZKNLdaDlV4T9NVzqCeG3ampl8C7v4mMbgnuXiUQv0JY25NXkXL0eWaW3OlsSKImTov/FvWZ9I6C54nYu+5TPwl5aWtF9V0jvT9VMkvzbtxnLzyZ9YUGWn0U= ; Message-ID: <20060106071807.87771.qmail@web30008.mail.mud.yahoo.com> Received: from [202.161.131.69] by web30008.mail.mud.yahoo.com via HTTP; Thu, 05 Jan 2006 23:18:07 PST Date: Thu, 5 Jan 2006 23:18:07 -0800 (PST) From: kamal kc To: freebsd MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Subject: 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: Fri, 06 Jan 2006 07:18:08 -0000 dear everbody, i have working to compress/decompress the packets. i know there are various schemes and facilities to do so in the freebsd, i have developed the compression facility myself. i am just a beginner in freebsd programming and overall in network programming. since i compress packet i add 2 byte custom header. now the problem is when the MTU sized packet is incompressible, i still add my 2 bytes which exceeds the MTU (1500) and the size becomes 1502. there was two options for me : either fragment the packet or increase the mtu. i don't want to fragment the packet as i think that is too much overhead for 2 bytes. rather i want to increase the mtu. i tried -->ifconfig xl1 mtu 1502 but it gave the message: -->ifconfig: ioctl (set mtu): invalid argument How can i increase the MTU ??? Will it have any effect whatsoever ??? i guess ethernet should support MTU of 1502. isn't it correct ?? help !! kamal __________________________________________ Yahoo! DSL – Something to write home about. Just $16.99/mo. or less. dsl.yahoo.com