H3C Technologies H3C SecPath F1000-E - Manual (Page 628)

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Configuring PIM
Protocol Independent Multicast (PIM) provides IP multicast forwarding by leveraging unicast static routes
or unicast routing tables generated by any unicast routing protocol, such as routing information protocol
(RIP), open shortest path first (OSPF), intermediate system to intermediate system (IS-IS), or border
gateway protocol (BGP). Independent of the unicast routing protocols running on the device, multicast
routing can be implemented as long as the corresponding multicast routing entries are created through
unicast routes. PIM uses the reverse path forwarding (RPF) mechanism to implement multicast forwarding.
When a multicast packet arrives on an interface of the device, it undergoes an RPF check. If the RPF check
succeeds, the device creates the corresponding routing entry and forwards the packet. If the RPF check
fails, the device discards the packet. For more information about RPF, see "Configuring multicast routing
and forwarding."
Based on the implementation mechanism, PIM falls into the following categories:
• Protocol Independent Multicast–Dense Mode (PIM-DM)
• Protocol Independent Multicast–Sparse Mode (PIM-SM)
• Protocol Independent Multicast Source-Specific Multicast (PIM-SSM)
To facilitate description, a network comprising PIM-capable routers is referred to as a "PIM domain" in
this document.
Configuring PIM in the Web interface
Before you configure PIM, you need to configure a unicast routing protocol so that all devices in the
domain are interoperable at the network layer.
Configuration task list
Configuring PIM-DM
Task Remarks
Globally enabling multicast routing
Required.
Globally enable multicast routing after selecting Network > Routing
Management > Multicast Routing. For more information, see
"Configuring multicast routing and forwarding."
By default, multicast routing is globally disabled.
Configuring PIM interfaces
Required.
Enable PIM-DM on an interface.
By default, PIM is disabled on an interface.
Displaying PIM neighbor information Optional.