Protocols And Standards; Hardware And Feature Compatibility - HP MSR2003 Configuration Manual

A Layer 2 device does not forward an MLD report through a non-router port because of the MLD report
suppression mechanism. For more information about the MLD report suppression mechanism, see
"Configuring MLD."
Done message
When a host leaves an IPv6 multicast group, the host sends an MLD done message to the Layer 3 devices.
When the Layer 2 device receives the MLD done message on a dynamic member port, the Layer 2 device
first examines whether a forwarding entry matches the IPv6 multicast group address in the message:
If no match is found, the Layer 2 device directly discards the MLD done message.
•
• If a match is found but the matching forwarding entry does not contain the port, the Layer 2 device
directly discards the MLD done message.
If a match is found and the matching forwarding entry contains the port, the Layer 2 device
•
forwards the done message to all router ports in the VLAN. The Layer 2 device does not
immediately remove the port from the forwarding entry. Instead, it adjusts the aging timer for the
port.
After receiving the MLD done message, the MLD querier resolves the IPv6 multicast group address in the
message. Then, it sends an MLD multicast-address-specific query to the IPv6 multicast group through the
port that received the done message.
After receiving the MLD multicast-address-specific query, the Layer 2 device forwards it through all its
router ports in the VLAN and all member ports of the IPv6 multicast group. Then, it waits for the
responding MLD reports from the directly connected hosts to check for the existence of members for the
IPv6 multicast group. For the port that receives the done message (assuming that it is a dynamic member
port), the Layer 2 device also performs one of the following actions:
• If the port receives an MLD report before the aging timer expires, the Layer 2 device resets the aging
timer for the port.
If the port does not receive any MLD report messages when the aging timer expires, the Layer 2
•
device removes the port from the forwarding entry for the IPv6 multicast group.

Protocols and standards

RFC 4541, Considerations for Internet Group Management Protocol (IGMP) and Multicast Listener
Discovery (MLD) Snooping Switches

Hardware and feature compatibility

This feature is supported on the following hardware:
MSR routers installed with the Layer 2 switching module SIC 4GSW, SIC 4GSWP, HMIM-24GSW,
HMIM-24GSWP, or HMIM-8GSW.
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