Pim Overview; Chapter 5 Pim Configuration - H3C S7500E Series Operation Manual

Operation Manual – Multicast
H3C S7500E Series Ethernet Switches
When configuring PIM, go to these sections for information you are interested in:

PIM Overview

Configuring PIM-DM
Configuring PIM-SM
Configuring PIM-SSM
Configuring PIM Common Information
Displaying and Maintaining PIM
PIM Configuration Examples
Troubleshooting PIM Configuration
Note:
The term "router" in this document refers to a router in a generic sense or a Layer 3
switch running the PIM protocol.
5.1 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 routing mechanism, PIM falls into two modes:
Protocol Independent Multicast–Dense Mode (PIM-DM), and
Protocol Independent Multicast–Sparse Mode (PIM-SM).

Chapter 5 PIM Configuration

5-1
Chapter 5 PIM Configuration