
Operation Manual – Multicast
H3C S5600 Series Ethernet Switches
Chapter 4 PIM Configuration
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Chapter 4 PIM Configuration
When configuring PIM, go to these sections for information you are interested in:
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PIM Overview
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Configuring PIM-DM
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Configuring PIM-SM
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Configuring Common PIM Parameters
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Displaying and Maintaining PIM
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PIM Configuration Examples
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Troubleshooting PIM
Note:
In this manual, the term “router” refers to a router in the generic sense or a Layer 3
Ethernet switch running an IP multicast protocol.
4.1 PIM Overview
Protocol Independent Multicast (PIM) provides IP multicast forwarding by leveraging
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 is subject to 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.
Based on the forwarding mechanism, PIM falls into two modes:
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Protocol Independent Multicast–Dense Mode (PIM-DM), and
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Protocol Independent Multicast–Sparse Mode (PIM-SM).