From owner-freebsd-questions@FreeBSD.ORG Fri Oct 27 14:11:39 2006 Return-Path: X-Original-To: freebsd-questions@FreeBSD.org Delivered-To: freebsd-questions@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1213416A47C for ; Fri, 27 Oct 2006 14:11:39 +0000 (UTC) (envelope-from freebsd-questions-local@be-well.ilk.org) Received: from mail1.sea5.speakeasy.net (mail1.sea5.speakeasy.net [69.17.117.3]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1729A43D97 for ; Fri, 27 Oct 2006 14:10:20 +0000 (GMT) (envelope-from freebsd-questions-local@be-well.ilk.org) Received: (qmail 13878 invoked from network); 27 Oct 2006 14:10:20 -0000 Received: from dsl092-078-145.bos1.dsl.speakeasy.net (HELO be-well.ilk.org) ([66.92.78.145]) (envelope-sender ) by mail1.sea5.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 27 Oct 2006 14:10:20 -0000 Received: by be-well.ilk.org (Postfix, from userid 1147) id 94BE628432; Fri, 27 Oct 2006 10:10:19 -0400 (EDT) To: "Mark Sellers" References: From: Lowell Gilbert Date: Fri, 27 Oct 2006 10:10:19 -0400 In-Reply-To: (Mark Sellers's message of "Wed, 25 Oct 2006 13:21:52 -0500") Message-ID: <44u01prgs4.fsf@be-well.ilk.org> User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.50 (berkeley-unix) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: freebsd-questions@FreeBSD.org Subject: Re: dual homing a freebsd server X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd-questions@FreeBSD.org List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Oct 2006 14:11:39 -0000 "Mark Sellers" writes: > I want to put two nic cards in a server, and have two separate gateways > assigned to each nic. I want one to master and the other slave. When the > primary network dies I want it to failover to the other card on the fly. > > > > Any help would be greatly appreciated. Technically, that isn't multi-homing, because you aren't planning to use both links at the same time. You might have gotten more responses if you had referred to "failover" in your subject line. There are a number of ways to do what you're looking for, but they will break existing connections when the failover occurs. That may or may not be a problem, depending on how long-lived the critical connections are for your server (and whether it can re-establish them on its own when they fail). There are some programs in ports that claim to do this sort of thing (e.g., net/balance), but I haven't used any. In general, the difficult part is detecting the failure -- if that problem is solved, scripting the failover is trivial. Note that the failure will typically not be on your physical link, so you can just watch the local interface. In the worst case, you use some kind of heartbeat protocol with a carefully-chosen router on your primary network, but there may be a better way depending on the precise configuration of that network. Good luck. -- Lowell Gilbert, embedded/networking software engineer, Boston area http://be-well.ilk.org/~lowell/