Multicast Listener Discovery(MLD)

MLD is an IPv6 protocol used on a local link for multicast group management. MLD operates in a manner similar to IGMP in IPv4 networks. MLD is enabled per VLAN and is analogous to the IPv4 IGMP protocol. In the factory default state (MLD disabled), the switch floods all IPv6 multicast traffic it receives on a given VLAN through all ports on that VLAN except the port receiving the inbound multicast traffic. Enabling MLD imposes management controls on IPv6 multicast traffic to reduce unnecessary bandwidth usage. MLD is configured per-VLAN. MLD can be configured using version 1 (MLDv1) or version 2 (MLDv2). MLDv2 introduces source-specific multicast in which the only packets delivered to the receiver are those that originate from a specified source address requested by the receiver. The receiver indicates interest in receiving traffic to a multicast address and additionally can indicate interest in receiving traffic from only one specified source sending to that multicast address. This reduces the amount of multicast routing information that should be maintained.These options are available for MLDv1 and MLDv2:

• Query interval-the time interval between general queries sent by the querier.

• Query Max Response Time-the amount of time to wait for a response to a query.

• Last Member Query Interval-the amount of time the querier waits to receive a response from members to a group-specific query message. It also specifies the amount of time between successive group-specific query messages.

• Robustness-the number of times to retry a query.

• Fast Learn-enables the port to learn group information when there is a topology change.