From owner-freebsd-stable@FreeBSD.ORG Sun Jun 13 02:12:05 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5D57A106566B; Sun, 13 Jun 2010 02:12:05 +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 274888FC13; Sun, 13 Jun 2010 02:12:04 +0000 (UTC) Received: from compute1.internal (compute1.internal [10.202.2.41]) by gateway1.messagingengine.com (Postfix) with ESMTP id 7A451F8155; Sat, 12 Jun 2010 22:12:04 -0400 (EDT) Received: from heartbeat1.messagingengine.com ([10.202.2.160]) by compute1.internal (MEProxy); Sat, 12 Jun 2010 22:12:04 -0400 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=messagingengine.com; h=message-id:date:from:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; s=smtpout; bh=p3tHpr3WG3uWZRODCxBz9pa1RLU=; b=ouIMU40oOSOh5CingQg7Zv02+BlCzNVT/3jd6xZQ6Q/VbrlhoN2epmNAW6MUIm/zHislFu4hVjTvYSv4/CRTgS7A+EWjBiKuCIYRmzvcSGzBFZFKPupE8ThFklKeydCEQXn80G7I7HPvGbP8IGtTg0yCvaB9ajZW4xlm0zI+Img= X-Sasl-enc: +hf2jQbwHxc5/Vmh/RKVwavTJ68t33zbaj+YR4GY/u/s 1276395124 Received: from [192.168.123.16] (cpc2-dals7-0-0-cust253.hari.cable.virginmedia.com [82.35.112.254]) by mail.messagingengine.com (Postfix) with ESMTPSA id B4CE44D6177; Sat, 12 Jun 2010 22:12:03 -0400 (EDT) Message-ID: <4C143E8E.5050406@incunabulum.net> Date: Sun, 13 Jun 2010 03:12:30 +0100 From: Bruce Simpson User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: Guy Helmer References: <4C0E81D7.8020209@earthlink.net> <4C0E8C59.5010202@earthlink.net> <8C598A97-0F1E-44A1-BAFE-48927C143553@palisadesystems.com> In-Reply-To: <8C598A97-0F1E-44A1-BAFE-48927C143553@palisadesystems.com> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: sclark46@earthlink.net, bms@freebsd.org, FreeBSD Stable Subject: Re: FreeBSD eats 169.254.x.x addressed packets X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 13 Jun 2010 02:12:05 -0000 Guy Helmer wrote: > My previous understanding was that RFC 3927 did not allow transmitting datagrams involving the 169.254.0.0/16 link-local prefix; now that I've looked over the RFC more closely, I'm not sure that is the case. > > I have cc'ed Bruce Simpson on this message in hopes that he can shed some light on this. I believe he committed the change that disallowed transmitting from 169.254.0.0/16 addresses. > RFC 3927 is pretty clear that 169.254.0.0/16 traffic is not to be forwarded beyond the link. I do not understand why the OP is losing traffic, unless he's relying on pre-RFC 3927 behaviour in his network topology. The IN_LINKLOCAL() check happens after ip_input() walks the address hash looking for exact address matches. So if an interface has a link-local address, the packet should get delivered upstack as usual. When I made this change, link-local addressing couldn't be fully implemented in FreeBSD, due to the lack of support for address scopes in the FreeBSD IPv4 code. Hopefully new people can pick up on it as they wish. thanks BMS