From owner-freebsd-net Thu Oct 26 14:46:49 2000 Delivered-To: freebsd-net@freebsd.org Received: from overlord.e-gerbil.net (e-gerbil.net [207.91.110.247]) by hub.freebsd.org (Postfix) with ESMTP id 295F037B4C5 for ; Thu, 26 Oct 2000 14:46:47 -0700 (PDT) Received: by overlord.e-gerbil.net (Postfix, from userid 1000) id 0D0935D6E; Thu, 26 Oct 2000 17:46:37 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by overlord.e-gerbil.net (Postfix) with ESMTP id 084991F1B; Thu, 26 Oct 2000 17:46:37 -0400 (EDT) Date: Thu, 26 Oct 2000 17:46:36 -0400 (EDT) From: "Richard A. Steenbergen" To: Nick Rogness Cc: Ron 'The InSaNe One' Rosson , freebsd-net@freebsd.org Subject: Re: Multihomed Routing In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Thu, 26 Oct 2000, Nick Rogness wrote: > On Thu, 26 Oct 2000, Ron 'The InSaNe One' Rosson wrote: > > > Yesterday I got into a discussion with one of my asociates about if a > > Network has 2 Routes out how do you tell your servers to switch between > > the routes without having to manually go in and change them. The > > discussion was not how the routers/switches were going to do it but how > > would are FreeBSD servers no what route to take out. Would the FreeBSD > > servers have to run routed or some other routing based deamon to know > > what there gateway route is? In theory we should not have to set a > > default route on this network for any of our machines. > > Yes you are correct. /usr/ports/net/gated I believe where you're going with this is using a router redundancy protocol like HSRP (Crisco version) or VRRP (standards based). This doesn't help you with optimal routing, but allows hosts to failover transparently without having to run gated or be included on any kind of IGP. This is often MUCH cleaner in practice. machineA ---| (10.1.1.3) |--- Router2-------(link x)---> (virtual 10.1.1.1)| | |--- Router1-------(link y)---> machineB ---| (10.1.2.2) The way this works is that you have two routers which talk to each other and create a fake virtual IP and MAC address to a virtual interface which floats between routers, and the machines are configured to use this fake ".1" as their gateway. The routers are configured to have one act as primary and the other in standby, and they constantly test each others status and take over in the event of a failure. You can also do semi advanced things such as load balancing by having half default to 1 as primary and half default to the other, and assign weight metrics and then have standby decisions made based on criteria such as link failures (for example, if link y dies, router 1 can automatically adjust its metrics to shift traffic to router 2 without having to pass it over the router1<->router2 link later). -- Richard A Steenbergen http://www.e-gerbil.net/humble PGP Key ID: 0x138EA177 (67 29 D7 BC E8 18 3E DA B2 46 B3 D8 14 36 FE B6) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message