From owner-freebsd-isp@FreeBSD.ORG Fri Aug 29 13:18:04 2003 Return-Path: Delivered-To: freebsd-isp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A7C4216A4BF for ; Fri, 29 Aug 2003 13:18:04 -0700 (PDT) Received: from energistic.com (12-223-237-12.client.insightbb.com [12.223.237.12]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3D11C43FF7 for ; Fri, 29 Aug 2003 13:18:03 -0700 (PDT) (envelope-from steve@energistic.com) Received: from energistic.com (smmsp@localhost [127.0.0.1]) by energistic.com (8.12.9/8.12.9) with ESMTP id h7TKHXAX018424; Fri, 29 Aug 2003 15:17:39 -0500 (EST) (envelope-from steve@energistic.com) Received: (from root@localhost) by energistic.com (8.12.9/8.12.9/Submit) id h7TKHWDJ017101; Fri, 29 Aug 2003 15:17:32 -0500 (EST) (envelope-from steve) Date: Fri, 29 Aug 2003 15:17:32 -0500 From: Charlie Root To: "Lapinski, Michael (Research)" Message-ID: <20030829201732.GA10482@energistic.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.4i cc: freebsd-isp@freebsd.org cc: 'Thomas Dwyer' Subject: Re: Multi-Homed Routing X-BeenThere: freebsd-isp@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Internet Services Providers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 29 Aug 2003 20:18:04 -0000 On Fri, Aug 29, 2003 at 03:18:41PM -0400, Lapinski, Michael (Research) wrote: > Are you using a fbsd box as a router? > > if no, you need to configure BGP on your border router. True that. > if yes, yuck, routers route, server's serve. =) True but an OS is neither a router nor a server. Its just an OS. The use you put it to defines if the box is a router or a server (or both). > I have recently added a 2nd Internet source (for redundancy) and I want to > know how to make FreeBSD choose a primary outbound internet source, and > chose the other if the primary is down? You'll need to be running a routing protocol. Your standard routing table probably isn't going to serve you very well. If aren't able to exchange protocol with your upstreams (usually with BGP) then you'll have to get clever with DNS tricks and route manipulation. Are you getting IP space from both providers? Are all services setup to listen on both subnets? Does your DNS point to both subnets? If one subnet goes down does DNS stop pointing to the bad subnet (only half a cure because the now bad subnet IPs are probably cached out there on the net somewhere anyway). The common situation is to advertise via a dynamic routing protocol such as BGP4 your IP space to both of your upstreams. This isn't really possible if your upstreams are DSL, cable or small-time wireless providers. > Am I correct to assume that FreeBSD will automatically return incoming > requests back through the interface that it arrived on? Ummm... no. I don't think you are. FBSD will likely send that packet back out whichever interface is labeled 'default' or, in the case of dynamic protocols, whichever route has the lowest metric back to the destination. -Steve