From owner-freebsd-net@FreeBSD.ORG Sun Jul 13 17:26:59 2003 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1F04337B401 for ; Sun, 13 Jul 2003 17:26:59 -0700 (PDT) Received: from hysteria.spc.org (hysteria.spc.org [195.206.69.234]) by mx1.FreeBSD.org (Postfix) with SMTP id 08BBB43F85 for ; Sun, 13 Jul 2003 17:26:58 -0700 (PDT) (envelope-from bms@hysteria.spc.org) Received: (qmail 13980 invoked by uid 5013); 14 Jul 2003 00:24:52 -0000 Date: Mon, 14 Jul 2003 01:24:52 +0100 From: Bruce M Simpson To: freebsd-net@freebsd.org Message-ID: <20030714002452.GC11966@spc.org> Mail-Followup-To: Bruce M Simpson , freebsd-net@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Organization: SPC Subject: ether_resolvemulti() doesn't expire routes X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Jul 2003 00:26:59 -0000 I noticed that if I do this:- # route add -net 224.0.0.0/4 -iface xl0 -expire 3000 The resultant cloned routes don't get given a lifetime, i.e. they're totally static and remain in the route table for the lifetime of the kernel. Either multicast designated receivers or IGMP aware routers are the two possible deployment scenarios I can think of which might want to hold on to multicast routes for a long period of time - but these same machines will probably be running mrouted, rather than using a simple primary-interface technique as above to leverage link-layer multicast. What's to stop a malicious user from writing a program which fills the routing table up with multicast routes which aren't actually used by the box? Would it not be a good idea to age these routes and thus prevent them from polluting the routing table in this case? BMS