The multicast optimizations in batman-adv are yet only usable and enabled in non-bridged scenarios. To be able to support bridged setups batman-adv needs to be able to detect IGMP/MLD queriers and reports on mesh nodes without bridges, too. See the following link for details: http://www.open-mesh.org/projects/batman-adv/wiki/Multicast-optimizations-listener-reports To avoid duplicate code between the bridge and batman-adv, the IGMP/MLD message validation code is moved from the bridge to the IPv4/IPv6 stack. On the way, some refactoring to increase readability and to iron out some subtle differences between the IGMP and MLD parsing code is done. Cheers, Linus Changelog v2: * Updated copyright for mcast_snoop.c