From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 1/2] IGMP snooping: set mrouters_only flag for IPv4 traffic properly Date: Thu, 16 Jun 2011 23:14:47 -0400 (EDT) Message-ID: <20110616.231447.1625738654020726451.davem@davemloft.net> References: <1307933995.2704.11.camel@nausicaa> <1308013301.3896.6.camel@nexus.oss.ntt.co.jp> <1308013483.3896.9.camel@nexus.oss.ntt.co.jp> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: herbert@gondor.hengli.com.au, shemminger@vyatta.com, netdev@vger.kernel.org, kakuta.hayato@oss.ntt.co.jp To: fernando@oss.ntt.co.jp Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:52381 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754886Ab1FQDO4 convert rfc822-to-8bit (ORCPT ); Thu, 16 Jun 2011 23:14:56 -0400 In-Reply-To: <1308013483.3896.9.camel@nexus.oss.ntt.co.jp> Sender: netdev-owner@vger.kernel.org List-ID: =46rom: Fernando Luis V=E1zquez Cao Date: Tue, 14 Jun 2011 10:04:43 +0900 > Upon reception of a IGMP/IGMPv2 membership report the kernel sets the > mrouters_only flag in a skb that may be a clone of the original skb, = which > means that sometimes the bridge loses track of membership report pack= ets (cb > buffers are tied to a specific skb and not shared) and it ends up for= wading > join requests to the bridge interface. >=20 > This can cause unexpected membership timeouts and intermitent/permane= nt loss > of connectivity as described in RFC 4541 [2.1.1. IGMP Forwarding Rule= s]: >=20 > A snooping switch should forward IGMP Membership Reports only to > those ports where multicast routers are attached. > [...] > Sending membership reports to other hosts can result, for IGMPv1 > and IGMPv2, in unintentionally preventing a host from joining a > specific multicast group. >=20 >=20 > Signed-off-by: Fernando Luis Vazquez Cao > Tested-by: Hayato Kakuta Applied.