704 Configuring L2 Multicast Featuresdiscarded, depending on the switch configuration. If a match is found, thenthe packet is forwarded only to the ports that are members of that multicastgroup.You can create multicast bridging groups and specify the ports and LAGs thatare members of each group. This allows L2 multicast traffic to be confined tothe specified group.You can configure the forwarding mode for each VLAN as one of thefollowing:• Forward Unregistered—Permitscontrol multicast frames to be forwarded.This means that multicast streams that have no registrants (no hosts havejoined the multicast group) will be flooded.• Filter Unregistered—Prohibits the forwarding ofcontrol multicast framessuch as router advertisements, RIP, and OSPF.• Forward All—Permits registered and unregistered multicast packets toforward.What Is IP Multicast Traffic?IP multicast traffic is traffic that is destined to a host group. Host groups areidentified by class D IP addresses, which range from 224.0.0.0 to239.255.255.255.When a packet with a broadcast or multicast destination IP address isreceived, the switch will forward a copy into each of the remaining networksegments in accordance with the IEEE MAC Bridge standard. Eventually, thepacket is made accessible to all nodes connected to the network.This approach works well for broadcast packets that are intended to be seen orprocessed by all connected nodes. In the case of multicast packets, however,this approach could lead to less efficient use of network bandwidth,particularly when the packet is intended for only a small number of nodes.Packets will be flooded into network segments where no node has any interestin receiving the packet.
