1-8
INCLUDE, (S1, S2...)) information based on the configured MLD SSM mappings and provides
SSM service accordingly.
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The MLD SSM mapping feature does not process MLDv2 reports.
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For more information about the IPv6 SSM group range, refer to
IPv6
PIM Configuration
in the
IP
Multicast Volume
.
MLD Proxying
In some simple tree-shaped topologies, it is not necessary to configure complex IPv6 multicast routing
protocols, such as IPv6 PIM, on the boundary device. Instead, you can configure MLD proxying on the
boundary device. 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 1-6
Network diagram for MLD proxying
As shown in
Figure 1-6
, two types of interfaces are defined on a MLD proxy device:
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Upstream interface: Also referred to as the proxy interface. A proxy interface is an interface on
which MLD proxying is configured. It is in the direction toward the root of the multicast forwarding
tree. An upstream interface acts as a host running MLD; therefore, it is also called host interface.
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Downstream interface: An interface that is running MLD and not in the direction toward the root of
the multicast forwarding tree. A downstream interface acts as a router running MLD; therefore, it is
also called router interface.
A device with MLD proxying configured maintains a group membership database, which stores the
group memberships on all the downstream interfaces in this database. Each entry comprises the
