Reference Guide

Multicast Support 369
16
Multicast Support
This chapter describes Multicast support on the device.
It contains the following topics:
•Overview
• Global Parameters
• Bridge Multicast Groups
• Bridge Multicast Forward All
• IGMP Snooping
• MLD Snooping
• Unregistered Multicast
• Multicast TV VLAN
Overview
Multicast forwarding enables a single packet to be forwarded to multiple
destinations. Layer 2 Multicast service is based on a Layer 2 device receiving a
single packet addressed to a specific Multicast address. Multicast forwarding
creates copies of the packet, and transmits the packets to the relevant ports.
There are two types of Multicast groups:
• Registered Multicast Group — When traffic addressed to a registered
Multicast group is received, it is handled according to its entry in the
Multicast Filtering Database and forwarded only to the registered
ports.
•
Unregistered Multicast Group — If traffic addressed to an
unregistered Multicast group is received, it is handled by a special
entry in the Multicast Filtering Database. The default setting of this is
to flood all such traffic (traffic in unregistered Multicast groups).