C-10
Cisco 3200 Series Router Hardware Reference
OL-5816-10
Appendix C Switch Port Functionality
IP Multicast Layer 3 Switching
IP Multicast Layer 3 Switching
This section describes how to configure IP multicast Layer 3 switching.
You m us t enable IP multicast routing globally before you can enable IP multicast Layer 3 switching on
Layer 3 interfaces.
For complete information and procedures, refer to these publications:
Cisco IOS IP Configuration Guide, Release 12.2, at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipr_c/
Cisco IOS IP Command Reference, Volume 1 of 3: Addressing and Services, Release 12.2 at this
URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipras_r/index.htm
Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols, Release 12.2 at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fiprrp_r/index.htm
Cisco IOS IP Command Reference, Volume 3 of 3: Routing Protocols, Release 12.2 at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fiprmc_r/index.htm
To enable IP multicast routing globally, Use this command in global configuration mode:

Enabling IP PIM on Layer 3 Interfaces

You must enable PIM on the Layer 3 interfaces before IP multicast Layer 3 switching functions on those
interfaces.
To enable IP PIM on a Layer 3 interface, use the following commands beginning in global configuration
mode:
This example shows how to enable PIM on an interface using the default mode (sparse-dense-mode):
Router(config-if)# ip pim
Router(config-if)#
This example shows how to enable PIM sparse mode on an interface:
Router(config-if)# ip pim sparse-mode
Router(config-if)#
Command Purpose
Router(config)# ip multicast-routing Enables IP multicast routing globally.
Command Purpose
Step 1 Router(config)# interface vlan
vlan_id
{slot/port}
Selects the interface to be configured.
Step 2 Router(config-if)# ip pim {dense-mode |
sparse-mode | sparse-dense-mode}
Enables IP PIM on a Layer 3 interface.