From owner-freebsd-net@FreeBSD.ORG Sat Dec 27 13:28:30 2003 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 CCBEE16A4CE for ; Sat, 27 Dec 2003 13:28:30 -0800 (PST) Received: from pit.databus.com (p70-227.acedsl.com [66.114.70.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8B4DE43D54 for ; Sat, 27 Dec 2003 13:28:27 -0800 (PST) (envelope-from barney@pit.databus.com) Received: from pit.databus.com (localhost.databus.com [127.0.0.1]) by pit.databus.com (8.12.9p2/8.12.9) with ESMTP id hBRLSHot011353; Sat, 27 Dec 2003 16:28:20 -0500 (EST) (envelope-from barney@pit.databus.com) Received: (from barney@localhost) by pit.databus.com (8.12.9p2/8.12.9/Submit) id hBRLS9Ej011351; Sat, 27 Dec 2003 16:28:09 -0500 (EST) (envelope-from barney) Date: Sat, 27 Dec 2003 16:28:09 -0500 From: Barney Wolff To: mark abrams Message-ID: <20031227212809.GA11242@pit.databus.com> References: <6.0.0.22.2.20031227155203.02738df0@10.222.222.77> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6.0.0.22.2.20031227155203.02738df0@10.222.222.77> User-Agent: Mutt/1.5.5.1i X-Scanned-By: MIMEDefang 2.37 cc: mi@aldan.algebra.com cc: net@freebsd.org Subject: Re: net access failover 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: Sat, 27 Dec 2003 21:28:30 -0000 On Sat, Dec 27, 2003 at 03:57:16PM -0500, mark abrams wrote: > > I have a cable modem and and a dsl connction to my machine. I would like to > use the cable modem as my default connection and automatically fail-over to > the dsl connection if/when the cable modem goes down. > > Can routed(8) do this ? If so how? And is there a better way ? I guess this should be a FAQ. For something that can be adapted to do what you want, see http://www.databus.com/dslsec.tgz . routed won't do it because (unlike real multihoming) your address on the two networks is different and the ISPs are not sending you any routing protocol packets. A simpleminded ping of the cable ISP's router, and changing the default route when it goes away and comes back, should work fine. NATing adds a little to the effort, if you do it. Existing connections will not survive a transition, but that's usually not a big deal. -- Barney Wolff http://www.databus.com/bwresume.pdf I'm available by contract or FT, in the NYC metro area or via the 'Net.