Mld Proxying; Protocols And Standards - HP MSR ASM Configuration Manual

MLD proxying

In a simple tree-shaped topology, you do not need to configure complex IPv6 multicast routing protocols,
such as IPv6 PIM, on edge devices. Instead, you can configure MLD proxying on these devices. With
MLD proxying configured, the device serves as a proxy for the downstream hosts to send MLD messages,
maintain group memberships, and implement IPv6 multicast forwarding based on the memberships. In
this case, the MLD proxy device is a host but no longer an IPv6 PIM neighbor to the upstream device.
Figure 78 Network diagram
As shown in
Upstream interface—Also called the "proxy interface." A proxy interface is an interface on which
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MLD proxying is configured. It is in the direction toward the root of the multicast forwarding tree. An
upstream interface acts as a host that is running MLD, and it is also called a "host interface."
Downstream interface—An interface that is running MLD and not in the direction toward the root of
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the multicast forwarding tree. A downstream interface acts as a router that is running MLD and it is
also called a "router interface."
An MLD proxy device maintains a group membership database, which stores the group memberships on
all the downstream interfaces in this database. Each entry comprises the multicast address, filter mode,
and source list. Such an entry is a collection of members in the same multicast group on each
downstream interface.
An MLD proxy device performs host functions on the upstream interface based on the database. It
responds to the queries according to the information in the database or sends join or leave messages
when the database changes. The MLD proxy device performs router functions on the downstream
interfaces by participating in the querier election, sending queries, and maintaining memberships based
on the reports.

Protocols and standards

RFC 2710, Multicast Listener Discovery (MLD) for IPv6
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RFC 3810, Multicast Listener Discovery Version 2 (MLDv2) for IPv6
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• RFC 4605, Internet Group Management Protocol (IGMP)/Multicast Listener Discovery (MLD)-Based
Multicast Forwarding ("IGMP/MLD Proxying")
Figure 78, an MLD proxy device has the following types of interfaces:
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