From owner-freebsd-net@FreeBSD.ORG Tue Dec 8 09:55:46 2009 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 CAFC21065692 for ; Tue, 8 Dec 2009 09:55:46 +0000 (UTC) (envelope-from andriys@gmail.com) Received: from mail-bw0-f213.google.com (mail-bw0-f213.google.com [209.85.218.213]) by mx1.freebsd.org (Postfix) with ESMTP id 5A8B98FC12 for ; Tue, 8 Dec 2009 09:55:46 +0000 (UTC) Received: by bwz5 with SMTP id 5so4245933bwz.3 for ; Tue, 08 Dec 2009 01:55:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=FuwUqxqLk8GQDdEGvyT8h0GfZyBZZKQCMLI3a7GuT1s=; b=x8zu98UZrcqAD/WiEPNF8S1gp/kdY6Z1AneZHMvQJKQxqnEHg0TG5w1NTA9nB5R0LO 6HBHN5LUm7fAYI30GJFad8F14GPnmviFc1O4YHMuNOwM2S03EegOP2/uF1+LntlE/aYr g7Nv3WqhNpvzQJPuJgOHbUpnwDmqEasBWo0gM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=KRWu8rZJF52FG29h3CaZL9Oj2fuAYO4wED8N+CMy6mykXtUoMHPwtLoeWK5KfG0NMk dSYlU6xBMH1KcY25dSUlvuVevRpS2GR6C0rQAxQoGurgpNEbJCJVoR0FIUXoFyzp4Oqj w4rmjjoKmCTJ3RcCikAgCFp1rVL2p0Yxe//mo= MIME-Version: 1.0 Received: by 10.204.2.211 with SMTP id 19mr8560423bkk.6.1260266144903; Tue, 08 Dec 2009 01:55:44 -0800 (PST) In-Reply-To: <4B1E1EF0.8040503@incunabulum.net> References: <200912071020.nB7AK77I023054@freefall.freebsd.org> <4B1CDEE5.6080507@incunabulum.net> <3e2b8dd90912070305t6ffc08a6gf7acd8890d028854@mail.gmail.com> <4B1D07C3.6090005@incunabulum.net> <3e2b8dd90912080114x31d962acqf2c8a360e7b5a83d@mail.gmail.com> <4B1E1EF0.8040503@incunabulum.net> Date: Tue, 8 Dec 2009 11:55:44 +0200 Message-ID: <3e2b8dd90912080155s544a7a50j17882b35f1343750@mail.gmail.com> From: Andriy Syrovenko To: Bruce Simpson Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-net@freebsd.org, flo@smeets.im Subject: Re: kern/138666: [multicast] [panic] not working multicast through igmpproxy 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: Tue, 08 Dec 2009 09:55:46 -0000 2009/12/8 Bruce Simpson : > Andriy Syrovenko wrote: >> >> I have switched to 8-STABLE. Kernel does not seem to crash anymore, >> however IGMP still does not work. tcpdump complains that outgoing IGMP >> report and leave packets have incorrect checksum- it is always 0. >> Though I'm not sure weather it is IGMP checksum or IP checksum that is >> incorrect. >> > > This just sounds like a fairly normal artefact of tcpdump/bpf with checks= um > offload, as I get the exactly same thing on my desktop w/ re(4). > > You need to confirm the checksums at the wire to be sure, or disable > rxcsum/txcsum: > =A0 # ifconfig re0 -txcsum -rxcsum I've checked w/ tcpdump on my MacBook connected to the same LAN segment the upstream interface of my router is connected to. The packets on the wire have bad checksums. And yes, I have re(4) interfaces as well. I'll try turning off checksum offloading today evening, as soon as I get to my router. > Nothing has changed in the behaviour of the code which computes IGMP > checksums; it does not depend on the outer IP header, and isn't touched b= y > IP checksum offload, unless your network card (or its driver) is doing > something it shouldn't be doing. I have looked through the tcpdump source code, and am now fairly confident that it is IP (not IGMP) checksum that is broken. > Perhaps Florian can shed some light on your IGMP issue? igmpproxy only > understands IGMPv2, afaik. Yep, it is igmp v2 only indeed.