Documentation/networking/bridge.rst

180 Multicast  chapter
183 The Linux bridge driver has multicast support allowing it to process Internet
184 Group Management Protocol (IGMP) or Multicast Listener Discovery (MLD)
185 messages, and to efficiently forward multicast data packets. The bridge
188 Multicast snooping
191 Multicast snooping is a networking technology that allows network switches
192 to intelligently manage multicast traffic within a local area network (LAN).
194 The switch maintains a multicast group table, which records the association
195 between multicast group addresses and the ports where hosts have joined these
197 received. With the multicast group information gathered through snooping, the
198 switch optimizes the forwarding of multicast traffic. Instead of blindly
199 broadcasting the multicast traffic to all ports, it sends the multicast
201 subscribed the respective destination multicast group.
203 When created, the Linux bridge devices have multicast snooping enabled by
204 default. It maintains a Multicast forwarding database (MDB) which keeps track
211 was added by `474ddb37fa3a ("net: bridge: multicast: add EHT allow/block handling")
217 latencies when a host leaves a multicast group or channel.
227 Other multicast features
230 The Linux bridge also supports `per-VLAN multicast snooping
232 which is disabled by default but can be enabled. And `Multicast Router Discovery
234 which help identify the location of multicast routers.