From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Multicast packets being lost (3.10 stable) Date: Mon, 24 Mar 2014 09:41:07 -0700 Message-ID: <20140324094107.2cfbf103@nehalam.linuxnetplumber.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: To: Linus =?ISO-8859-1?B?TPxzc2luZw==?= , "David Miller" Return-path: Received: from mx0b-000f0801.pphosted.com ([67.231.152.113]:11267 "EHLO mx0b-000f0801.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752675AbaCXQlb convert rfc822-to-8bit (ORCPT ); Mon, 24 Mar 2014 12:41:31 -0400 Sender: netdev-owner@vger.kernel.org List-ID: We are seeing multicast snooping related issues. Is there some reason this commit never went into stable (3.10) commit b00589af3b04736376f24625ab0b394642e89e29 Author: Linus L=FCssing Date: Thu Aug 1 01:06:20 2013 +0200 bridge: disable snooping if there is no querier =20 If there is no querier on a link then we won't get periodic reports= and therefore won't be able to learn about multicast listeners behind p= orts, potentially leading to lost multicast packets, especially for multi= cast listeners that joined before the creation of the bridge. =20 These lost multicast packets can appear since c5c23260594 ("bridge: Add multicast_querier toggle and disable queries by defau= lt") in particular. =20 With this patch we are flooding multicast packets if our querier is disabled and if we didn't detect any other querier. =20 A grace period of the Maximum Response Delay of the querier is adde= d to give multicast responses enough time to arrive and to be learned fr= om before disabling the flooding behaviour again. =20 Signed-off-by: Linus L=FCssing Signed-off-by: David S. Miller