From owner-freebsd-net@FreeBSD.ORG Tue Dec 16 10:57:14 2008 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 400C71065670 for ; Tue, 16 Dec 2008 10:57:14 +0000 (UTC) (envelope-from randy@psg.com) Received: from ran.psg.com (ran.psg.com [IPv6:2001:418:1::36]) by mx1.freebsd.org (Postfix) with ESMTP id 2ECA98FC20 for ; Tue, 16 Dec 2008 10:57:14 +0000 (UTC) (envelope-from randy@psg.com) Received: from 50.216.138.210.bn.2iij.net ([210.138.216.50] helo=rmac.psg.com) by ran.psg.com with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1LCXc1-0001mi-If; Tue, 16 Dec 2008 10:57:13 +0000 Message-ID: <49478988.2070208@psg.com> Date: Tue, 16 Dec 2008 19:57:12 +0900 From: Randy Bush User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20081204 Thunderbird/3.0b1 MIME-Version: 1.0 To: Gabe Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: FreeBSD network failover 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: Tue, 16 Dec 2008 10:57:14 -0000 >>> I have a nat'd box which obviously has an internal and external ip >>> address. The box has a third interface which is configured to a >>> DSL connection. My goal is for that interface to be activated if >>> the external side fails so that outbound traffic still flows. Any >>> of you know of a way to accomplish this regardless of the type of >>> failure. >> what routing protocols are involved? > Its just IP and nat and there is an IPSec tunnel in place. I need to > know that if the ISP goes out the DSL connection will be able to do > certain things, like say sending an email to a pager letting us know > that the main connection went down. freebsd does not allow metrics on static routes, which would be the 'normal' hack. i.e. you can not have two default routes with different weights. so you may be left with a scripted hack which pings, or otherwise checks, the next hops of the two exits and adds/deletes default routes appropriately. randy