From owner-freebsd-net@FreeBSD.ORG Mon Mar 3 13:06:57 2008 Return-Path: Delivered-To: net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CC0651065670 for ; Mon, 3 Mar 2008 13:06:57 +0000 (UTC) (envelope-from bms@FreeBSD.org) Received: from out3.smtp.messagingengine.com (out3.smtp.messagingengine.com [66.111.4.27]) by mx1.freebsd.org (Postfix) with ESMTP id AD55A8FC12 for ; Mon, 3 Mar 2008 13:06:57 +0000 (UTC) (envelope-from bms@FreeBSD.org) Received: from compute1.internal (compute1.internal [10.202.2.41]) by out1.messagingengine.com (Postfix) with ESMTP id 07251AC61F; Mon, 3 Mar 2008 07:47:42 -0500 (EST) Received: from heartbeat2.messagingengine.com ([10.202.2.161]) by compute1.internal (MEProxy); Mon, 03 Mar 2008 07:47:42 -0500 X-Sasl-enc: qqFc1K6f+6jM9gLE9YKSwP+lg8JpQtlw+S7GyRpT7Dd3 1204548461 Received: from empiric.lon.incunabulum.net (82-35-112-254.cable.ubr07.dals.blueyonder.co.uk [82.35.112.254]) by mail.messagingengine.com (Postfix) with ESMTPSA id 138402C6C0; Mon, 3 Mar 2008 07:47:40 -0500 (EST) Message-ID: <47CBF36C.9000702@FreeBSD.org> Date: Mon, 03 Mar 2008 12:47:40 +0000 From: "Bruce M. Simpson" User-Agent: Thunderbird 2.0.0.9 (X11/20080207) MIME-Version: 1.0 To: Willem Jan Withagen References: <497111.42659.qm@web63905.mail.re1.yahoo.com> <20080301225727.GA85851@owl.midgard.homeip.net> <47CAADB8.9000202@digiware.nl> <47CC304F.6040006@bromirski.net> <47CBF16C.6020704@digiware.nl> In-Reply-To: <47CBF16C.6020704@digiware.nl> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Cc: =?ISO-8859-1?Q?=3Fukasz_Bromirski?= , net@freebsd.org, Ingo Flaschberger , Barney Cordoba Subject: Re: FBSD 1GBit router? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 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, 03 Mar 2008 13:06:57 -0000 Willem Jan Withagen wrote: > =A3ukasz Bromirski wrote: >> Wouldn't it be a case for use of multicast vs unicast? Hardware >> is always better anyway, so why not invest in some switch that >> can do unicast/multicast in hardware? > > Usefull suggestion, only this is going to be in an overlay cloud where > we do not have control over all the endpoint networks. let alone that w= e > can get them to use multicast. And even those that use multicast in the= ir > last-mule equipment, don't always have correct setups. > > My experience is that Multicast in nice in theory and experiment, but=20 > when > push comes to shove it does not completely deliver. I have to agree wholeheartedly, for more detail than you can shake a=20 stick at, look here: http://www.cs.ucr.edu/~michalis/COURSES/204-02b/papers/ramalho.html If you're running over MPLS all bets are off. MPLS is like ATM in the=20 sense that it ain't got no multicast grok, as far as I can fathom,=20 anyway. Label switching is label switching. I never saw any support for=20 the notion of 1:M in the LSPs. Multicast is more likely to succeed at the moment when you have complete = knowledge of the network topology, and IP layer visibility. There are=20 ongoing efforts to address these limitations. later BMS