From owner-freebsd-net Thu Mar 7 15:34:25 2002 Delivered-To: freebsd-net@freebsd.org Received: from outboundx.mv.meer.net (outboundx.mv.meer.net [209.157.152.12]) by hub.freebsd.org (Postfix) with ESMTP id E781A37B400 for ; Thu, 7 Mar 2002 15:34:21 -0800 (PST) Received: from mail.meer.net (mail.meer.net [209.157.152.14]) by outboundx.mv.meer.net (8.11.6/8.11.6) with ESMTP id g27NYGs12000; Thu, 7 Mar 2002 15:34:16 -0800 (PST) (envelope-from gnn@neville-neil.com) Received: from neville-neil.com ([209.157.133.226]) by mail.meer.net (8.12.1/8.12.1/meer) with ESMTP id g27NYGcI087209; Thu, 7 Mar 2002 15:34:21 -0800 (PST) Message-Id: <200203072334.g27NYGcI087209@mail.meer.net> X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Garrett Wollman Cc: FreeBSD Networking Subject: Re: How can I give one route priority over the other route ? In-Reply-To: Message from Garrett Wollman of "Thu, 07 Mar 2002 18:18:49 EST." <200203072318.g27NIn006328@khavrinen.lcs.mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 07 Mar 2002 15:34:16 -0800 From: "George V. Neville-Neil" Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org > > This is an issue with the routing system design. Many routers > > allow duplicate routes (same netmask) that have different priorities. > > This makes it quicker to switch routes during a failure. > > FreeBSD permits this as well. It is the responsibility of the routing > process to manage which specific route is installed in the kernel > forwarding table at any given time. (FreeBSD's `routed' can do this > in some instances.) FreeBSD does not directly support multiple static > routes to a given destination, since it has no knowledge which would > enable it to choose among them; again, a routing process can be used > to manage this. FreeBSD permits this so long as you write a program to do it. The kernel table is not really a routing table as many networking folks would define it. It's a forwarding table mixed with other things. In many routing systems there is a routing table that multiple routing processes can share. It is a common database and is treated as such. It is from this arena that such questions arise. The way things work in FreeBSD is that you run a single routing process (Zebra, Routed, GateD etc.) that maintains a real routing database and then periodically pushing things down into the kernel. Later, George -- George V. Neville-Neil gnn@neville-neil.com NIC:GN82 "Those who would trade liberty for temporary security deserve neither" - Benjamin Franklin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message