Install guide

IP Multicasting 5
When the switch finds out from IGMP that a new host has joined a multicast
group on one of its interfaces, the switch needs to receive the multicast traffic
for this group, so that it can forward it to the host. The switch uses the
multicast routing protocol (PIM-SM or PIM-DM) to notify routers closer to the
sender (upstream) to forward it traffic for the group. Routers running a
multicast routing protocol, such as Protocol-Independent Multicast (PIM),
maintain forwarding tables to forward multicast packets. PIM Sparse Mode
and PIM Dense Mode share a multicast forwarding table.
Interoperability between Multicast
Routing Protocols
The switch can be configured as a Multicast Border Router (MBR), as specified
in RFC 2715, Interoperability Rules for Multicast Routing Protocols. A Multicast
Border Router forms the border between two or more multicasting domains
that are running different multicast routing protocols (PIM-SM or PIM-DM).
The MBR forwards multicast packets across the different domains so that
receivers in one domain can receive packets from sources in another domain.
Therefore different interfaces on the switch can be configured as PIM-SM or
PIM-DM interfaces.
The switch treats sources that are reached via another multicasting domain as if
they were directly connected sources.
The IP configuration of an interface cannot be changed while PIM is attached to
the interface. The PIM interface must first be deleted, and then re-added after
the IP changes have been made.