From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus =?utf-8?Q?L=C3=BCssing?= Subject: Re: Multicast packets being lost (3.10 stable) Date: Tue, 25 Mar 2014 14:06:07 +0100 Message-ID: <20140325125231.GW6008@Linus-Debian> References: <20140324094107.2cfbf103@nehalam.linuxnetplumber.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: David Miller , Linus =?utf-8?Q?L=C3=BCssing?= , netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from mout.web.de ([212.227.15.14]:61273 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751886AbaCYNGN (ORCPT ); Tue, 25 Mar 2014 09:06:13 -0400 Content-Disposition: inline In-Reply-To: <20140324094107.2cfbf103@nehalam.linuxnetplumber.net> Sender: netdev-owner@vger.kernel.org List-ID: That commit is supposed to be a fix and seems to be a easily cherry-pickable on top of 3.10. So I think it's suitable for stable There are two follow-up commit for this particular patch that I'm aware of: "bridge: separate querier and query timer into IGMP/IPv4 and MLD/IPv6 ones" (cc0fdd80). That's just an optimization and can be ignored for stable. The second one is "bridge: don't try to update timers in case of broken MLD queries" (248ba8ec0). Which is a direct fix for b00589af3 and should therefore go into stable, too, if b00589af3 goes into stable. Cheers, Linus On Mon, Mar 24, 2014 at 09:41:07AM -0700, Stephen Hemminger wrote: > We are seeing multicast snooping related issues. > Is there some reason this commit never went into stable (3.10) >=20 > commit b00589af3b04736376f24625ab0b394642e89e29 > Author: Linus L=C3=BCssing > Date: Thu Aug 1 01:06:20 2013 +0200 >=20 > bridge: disable snooping if there is no querier > =20 > If there is no querier on a link then we won't get periodic repor= ts and > therefore won't be able to learn about multicast listeners behind= ports, > potentially leading to lost multicast packets, especially for mul= ticast > 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 def= ault") > 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 ad= ded to > give multicast responses enough time to arrive and to be learned = from > before disabling the flooding behaviour again. > =20 > Signed-off-by: Linus L=C3=BCssing > Signed-off-by: David S. Miller