Cisco 10000 - Manual (Page 337)

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Cisco 10000 Series Router Software Configuration Guide
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Chapter 15 Configuring IP Multicast
Configuration Tasks for IP Multicast Routing
Enabling IP Multicast Routing
IP multicast routing allows the Cisco IOS software to forward multicast packets. To enable IP multicast
routing on the Cisco 10000 router, enter the following command in global configuration mode:
Note If you enable IP multicast fast switching on one interface, you must enable it on all outbound interfaces
on the router. Failure to do so results in the router sending duplicate multicast packets out the interface
that has fast switching enabled.
Enabling PIM on an Interface
The protocol-independent multicast (PIM) protocol maintains the current IP multicast service mode of
receiver initiated membership. Enabling PIM on an interface also enables IGMP operation on that
interface. Configure an interface in one of the following modes:
• Dense mode
• Sparse mode
• Sparse-dense mode
The mode determines how the Cisco 10000 router populates its multicast routing table and how it
forwards multicast packets it receives from its directly connected LANs. You must enable PIM in one of
these modes for an interface to perform IP multicast routing.
For more information, see the “IP Multicast” chapter in the Cisco IOS IP Configuration Guide,
Release 12.2.
Enabling Dense Mode
To configure PIM on an interface to be in dense mode, enter the following command in interface
configuration mode:
Command Purpose
Router(config)# ip multicast-routing Enables IP multicast routing.
Command Purpose
Router(config-if)# ip pim dense-mode Enables dense mode PIM on the interface.