Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261947AbTHTMzP (ORCPT ); Wed, 20 Aug 2003 08:55:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261946AbTHTMzP (ORCPT ); Wed, 20 Aug 2003 08:55:15 -0400 Received: from e34.co.us.ibm.com ([32.97.110.132]:13462 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S261934AbTHTMzF (ORCPT ); Wed, 20 Aug 2003 08:55:05 -0400 Message-ID: <3F436EF9.1040502@us.ibm.com> Date: Wed, 20 Aug 2003 08:52:09 -0400 From: Harley Stenzel User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030625 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "David S. Miller" Cc: Richard Underwood , skraw@ithnet.com, willy@w.ods.org, alan@lxorguk.ukuu.org.uk, carlosev@newipnet.com, lamont@scriptkiddie.org, davidsen@tmr.com, bloemsaa@xs4all.nl, marcelo@conectiva.com.br, netdev@oss.sgi.com, linux-net@vger.kernel.org, layes@loran.com, torvalds@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [2.4 PATCH] bugfix: ARP respond on all devices References: <353568DCBAE06148B70767C1B1A93E625EAB5D@post.pc.aspectgroup.co.uk> <20030819112103.373fce27.davem@redhat.com> In-Reply-To: <20030819112103.373fce27.davem@redhat.com> X-MIMETrack: Itemize by SMTP Server on D03NM118/03/M/IBM(Release 6.0.2CF2|July 23, 2003) at 08/20/2003 06:52:10, Serialize by Router on D03NM118/03/M/IBM(Release 6.0.2CF2|July 23, 2003) at 08/20/2003 06:52:50, Serialize complete at 08/20/2003 06:52:50 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1224 Lines: 32 David S. Miller wrote: > On Tue, 19 Aug 2003 19:05:13 +0100 > Richard Underwood wrote: > >> The ARP request represents all FUTURE >>packets being sent out that interface, not just the one single packet that >>happened to kick of this ARP request. > > That's RIGHT! And by your own argument the source address > in the ARP request IS IRRELEVANT and is to be ignored! > The source address in the ARP request is not irrelevant, because a broadcast arp request causes all recipients of that broadcast request to update their arp cache entry (if they have a cache entry for that IP) for the IP specified in the source with the MAC specified in the request. So, in an environment where a single address is aliased in multiple places, such as tunnel endpoints and loopback aliases, and in multi-homed same-segment configs, it is unpredictable asto which IP will be bound to which MAC for every machine (or arp cache) on the network. --Harley - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/