From owner-freebsd-net@FreeBSD.ORG Mon Apr 25 19:28:46 2005 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 A8A1016A4CE for ; Mon, 25 Apr 2005 19:28:46 +0000 (GMT) Received: from arginine.spc.org (arginine.spc.org [83.167.185.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id 611EE43D41 for ; Mon, 25 Apr 2005 19:28:46 +0000 (GMT) (envelope-from bms@spc.org) Received: from localhost (localhost [127.0.0.1]) by arginine.spc.org (Postfix) with ESMTP id 493E36530A; Mon, 25 Apr 2005 20:28:03 +0100 (BST) Received: from arginine.spc.org ([127.0.0.1]) by localhost (arginine.spc.org [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 91644-04-8; Mon, 25 Apr 2005 20:28:02 +0100 (BST) Received: from empiric.dek.spc.org (host81-134-90-164.in-addr.btopenworld.com [81.134.90.164]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by arginine.spc.org (Postfix) with ESMTP id 6BDDA651F7; Mon, 25 Apr 2005 20:28:02 +0100 (BST) Received: by empiric.dek.spc.org (Postfix, from userid 1001) id 9298464CF; Mon, 25 Apr 2005 20:28:41 +0100 (BST) Date: Mon, 25 Apr 2005 20:28:41 +0100 From: Bruce M Simpson To: Eivind Hestnes Message-ID: <20050425192841.GD2339@empiric.icir.org> References: <426D2712.4080707@stabbursmoen.no> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <426D2712.4080707@stabbursmoen.no> cc: net@FreeBSD.org Subject: Re: Multicast routing with VLANs 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, 25 Apr 2005 19:28:46 -0000 Hi, On Mon, Apr 25, 2005 at 07:21:22PM +0200, Eivind Hestnes wrote: > I'm trying to get mrouted to route multicast traffic between multiple > VLANs on a FreeBSD 5.4-RC3 machine. Mrouted starts as expected, and > according to /var/log/messages it's running - but the multicast routing > itself don't work. While Googling, I noticed in kern/78821 > (http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/78821) that FreeBSD > fails to set the ALLMULTI flag on the parent device when using the > if_em(4). I have tried to set the ALLMULTI flag manually, but with no > further success - The flag won't set. > > I need the multicast routing to get Norton Ghost work properly, and > currently I'm a bit stuck.. It is very very possible that ALLMULTI doesn't work right on cards which have hardware VLAN tagging support, though I haven't investigated it. For situations where the underlying hardware or card firmware cannot support the notion of ALLMULTI (receive all multicast datagrams promiscuously), it would be necessary to spoof it up by putting the hardware into promiscuous mode. NetBSD has a flag called M_PROMISC. Why is this relevant? Well, one thing I've noticed is that if you're running regular unicast forwarding on a box, and then put one of the interfaces into PROMISC mode, the danger is that the box will then begin trying to forward the datagrams it's just forwarded. We'd need a way to differentiate between traffic addressed to us and not addressed to us by MAC address when forwarding. Sadly ENOTIME at the moment for writing patches. :-( Regards, BMS