From owner-freebsd-net@FreeBSD.ORG Tue Sep 14 17:07:15 2004 Return-Path: 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 AB44D16A4CE; Tue, 14 Sep 2004 17:07:15 +0000 (GMT) Received: from corbulon.video-collage.com (corbulon.video-collage.com [64.35.99.179]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4815E43D39; Tue, 14 Sep 2004 17:07:15 +0000 (GMT) (envelope-from mi+mxmoz@aldan.algebra.com) Received: from 250-217.customer.cloud9.net (195-11.customer.cloud9.net [168.100.195.11])i8EH7DC8037170 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 14 Sep 2004 13:07:14 -0400 (EDT) (envelope-from mi+mxmoz@aldan.algebra.com) Received: from [127.0.0.1] (mteterin@localhost [127.0.0.1]) i8EH7786077152; Tue, 14 Sep 2004 13:07:07 -0400 (EDT) (envelope-from mi+mxmoz@aldan.algebra.com) Message-ID: <4147253B.8020004@aldan.algebra.com> Date: Tue, 14 Sep 2004 13:07:07 -0400 From: Mikhail Teterin User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; uk-UA; rv:1.7) Gecko/20040702 X-Accept-Language: uk, en-us, en MIME-Version: 1.0 To: questions@FreeBSD.org, net@FreeBSD.org Content-Type: text/plain; charset=KOI8-U; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamd / ClamAV version devel-20040615, clamav-milter version 0.73a on corbulon.video-collage.com X-Virus-Status: Clean X-Scanned-By: MIMEDefang 2.43 Subject: Using `route .... -mtu' on local network X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Sep 2004 17:07:15 -0000 Hello! Most of our hosts can only do the regular 1500-byte frames, but some are Jumbo Frames capable. I'm trying to make these few servers talk to _each other_ using bigger frames (the switch supports them) without breaking the LAN into subnets. In the past someone suggested, I try explicit -mtu switch to the route(8). So, with two -current machines on the same LAN (`mi' and `pandora') I try: mi# route add pandora -iface em0 -mtu 4000 add host pandora: gateway em0 mi# route get pandora route to: pandora destination: pandora interface: em0 flags: recvpipe sendpipe ssthresh rtt,msec rttvar hopcount mtu expire 0 0 0 0 0 0 4000 0 Even ping-ing pandora stops working.... I have to `route delete pandora' for things to recover. Any suggestions? Thanks! -mi