Owner's Manual

Chapter 28. IPv6 Multicast | 759

28. IPv6 Multicast

This chapter includes the following sections:

• Overview on page 759

• Managing MLD on page 760

Overview

IPv6 multicast is a function that allows a single IPv6 host to send a packet to a group of IPv6

hosts.

Multicast Listener Discovery (MLD) is a protocol used by an IPv6 host to register its IP multicast

group membership with a router. To receive multicast traffic, a host must explicitly join a multicast

group by sending an MLD report; then, the traffic is forwarded to that host. Periodically, the router

queries the multicast group to see if the group is still in use. If the group is still active, a single IP

host responds to the query, and group registration is maintained.

MLD is the IPv6 equivalent to IGMP, and MLDv1 is equivalent to IGMPv2. The XCM8800

software supports the MLDv1 protocol. However, to overcome a hardware limitation, IPv6

multicast packets for a group are flooded.

Note: This release supports host registration through MLD, but it does not

support IPv6 multicast routing. If the switch is connected to an IPv6

multicast router, it can register for IPv6 multicast groups and forward

IPv6 multicast traffic.

Note: This release does not support MLD snooping. If any IPv6 host on a

VLAN registers for an IPv6 multicast group, traffic for the IPv6

multicast group is flooded to all ports on the VLAN.