From owner-freebsd-net@FreeBSD.ORG Wed Dec 24 14:16:53 2008 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E6511106568A; Wed, 24 Dec 2008 14:16:53 +0000 (UTC) (envelope-from bms@incunabulum.net) Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by mx1.freebsd.org (Postfix) with ESMTP id B4F428FC14; Wed, 24 Dec 2008 14:16:53 +0000 (UTC) (envelope-from bms@incunabulum.net) Received: from compute2.internal (compute2.internal [10.202.2.42]) by out1.messagingengine.com (Postfix) with ESMTP id 4782B1F4FDD; Wed, 24 Dec 2008 09:16:53 -0500 (EST) Received: from heartbeat1.messagingengine.com ([10.202.2.160]) by compute2.internal (MEProxy); Wed, 24 Dec 2008 09:16:53 -0500 X-Sasl-enc: o6f51Gzd5M1PPItepSC1ie5jW4a+9eJvdHwxKMRI3XGb 1230128212 Received: from anglepoise.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 36CF724E1A; Wed, 24 Dec 2008 09:16:52 -0500 (EST) Message-ID: <49524453.7080709@incunabulum.net> Date: Wed, 24 Dec 2008 14:16:51 +0000 From: Bruce Simpson User-Agent: Thunderbird 2.0.0.18 (X11/20081204) MIME-Version: 1.0 To: Kip Macy References: <55f001c9639d$875f14ec$7202020a@internal.cacheflow.com> <4950F770.3090700@dlr.de> <3c1674c90812231408h53b16b4as5d3fa242e6d02a10@mail.gmail.com> In-Reply-To: <3c1674c90812231408h53b16b4as5d3fa242e6d02a10@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Qing Li , "Li, Qing" , freebsd-current@freebsd.org, Hartmut Brandt , freebsd-net@freebsd.org Subject: Comment re ARP work and ad-hoc networking 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: Wed, 24 Dec 2008 14:16:54 -0000 The ARPv2 snap makes things that much more interesting. I can foresee that folk may wish to do things e.g. with MANET protocols. In an ad-hoc wireless world, things happen very differently. Both ARP and IGMP straddle layer boundaries in the ISO 7 -layer model, and are geared towards fixed network topologies which don't change dynamically over small t time. Nothing out there in open source land really deals with the split all that elegantly. Because ad-hoc protocols enable the endpoints to discover each other dynamically, and there may be multiple ingress/egress points, you can effectively populate the ARP table i.e. based on MANET "hello" messages. Of course now that ARP is out of the routing table, this probably makes things easier in this regard. But as Sam points out, we may be better off with a new kernel comm mechanism. Linux's netlink socket has an Informational RFC, and as such is not subject to the GPL -- one cannot copyright an idea. Whilst implementing it would be a lot of work, it is one good way to proceed as it then ties everything together under one API, which would greatly help folk writing network apps. Of course, without a compelling case for going off and doing the work (i.e. funded), this is largely hand-waving and just a suggestion I'm putting out 'out there'. just my 2p BMS