Subject: Multicast packets being lost (3.10 stable)

From: Stephen Hemminger <[email-masked]>
Date: Mon, 24 Mar 2014 09:41:07 -0700

We are seeing multicast snooping related issues.
Is there some reason this commit never went into stable (3.10)

commit b00589af3b04736376f24625ab0b394642e89e29
Author: Linus Lüssing <[email-masked]>
Date:   Thu Aug 1 01:06:20 2013 +0200

    bridge: disable snooping if there is no querier
    
    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 ports,
    potentially leading to lost multicast packets, especially for multicast
    listeners that joined before the creation of the bridge.
    
    These lost multicast packets can appear since c5c23260594
    ("bridge: Add multicast_querier toggle and disable queries by default")
    in particular.
    
    With this patch we are flooding multicast packets if our querier is
    disabled and if we didn't detect any other querier.
    
    A grace period of the Maximum Response Delay of the querier is added to
    give multicast responses enough time to arrive and to be learned from
    before disabling the flooding behaviour again.
    
    Signed-off-by: Linus Lüssing <[email-masked]>
    Signed-off-by: David S. Miller <[email-masked]>