Network Router User Manual

Router and Switch Multicast Configuration
This document is not a network multicast configuration guide. Refer to Configuring IP Multicast Routing for
a complete implementation story. This document covers the basics to enable multicast within your network
environment.
Enable IP Multicast Routing
IP multicast routing allows the Cisco IOS® software to forward multicast packets. The ip multicast−routing
global configuration command is required to allow multicast to function in any multicast enabled network.
The ip multicast−routing command should be enabled on all routers within your network between the
WLC(s) and their respective access points.
Router(config)#ip multicast−routing
Enable PIM on an Interface
This enables the routing interface for Internet Group Management Protocol (IGMP) operation. The Protocol
Independent Multicast (PIM) mode determines how the router populates its multicast routing table. The
example provided here does not require the rendezvous point (RP) to be known for the multicast group and
therefore sparse−dense−mode is the most desirable given the unknown nature of your multicast environment.
This is not a multicast recommendation to be configured to work although the Layer 3 interface directly
connected to your controller should be PIM enabled for multicast to function. All interfaces between your
WLC(s) and their respective access points should be enabled.
Router(config−if)#ip pim sparse−dense−mode