Cisco Systems 78-11741-02 manual Configuring the Access Router, IPC-443

Configuring IP Multicast Routing

Load Splitting IP Multicast Traffic Across Equal-Cost Paths Configuration Task List

If a tunnel is configured between Router A and Router B, and multicast traffic is made to reverse path forward over the tunnel, then the multicast packets are sent encapsulated into the tunnel as unicast packets between Router A and Router B. The underlying unicast mechanism will then perform load splitting across the equal-cost links.

To configure load splitting across tunnels, perform the tasks described in the following sections. The tasks in the first three sections are required; the task in the remaining section is optional.

•Configuring the Access Router (Required)

•Configuring the Router at the Opposite End of the Tunnel (Required)

•Configuring Both Routers to RPF (Required)

•Verifying the Load Splitting (Optional)

Configuring the Access Router

To configure the access router end of the tunnel (the end of the tunnel near the source), use the following commands beginning in global configuration mode. The tunnel mode is GRE IP by default.

	Command			Purpose
Step 1
	Router(config)# interface	tunnel	number	Configures a tunnel interface.
Step 2
	Router(config-if)# ip unnumbered		type number	Enables IP processing without assigning an IP address
				to the interface.
Step 3
	Router(config-if)# ip pim	{dense-mode		Enables PIM on the tunnel interface.
	sparse-mode sparse-dense-mode}
Step 4
	Router(config-if)# tunnel	source	{ip-address	Configures the tunnel source.
	type number}
Step 5
	Router(config-if)# tunnel	destination {hostname		Configures the tunnel destination.
	ip-address}

Configuring the Router at the Opposite End of the Tunnel

After configuring the access router end of the tunnel, use the following commands on the router at the opposite end of the tunnel beginning in global configuration mode:

	Command	Purpose
Step 1
	Router(config)# interface tunnel number	Configures a tunnel interface.
Step 2
	Router(config-if)# ip unnumbered type number	Enables IP processing without assigning an IP address
		to the interface.
Step 3
	Router(config-if)# ip pim {dense-mode	Enables PIM on the tunnel interface.
	sparse-mode sparse-dense-mode}
Step 4
	Router(config-if)# tunnel source {ip-address	Configures the tunnel source. This configuration
	type number}	matches the tunnel destination at the opposite end of
		the tunnel.
Step 5
	Router(config-if)# tunnel destination {hostname	Configures the tunnel destination. This configuration
	ip-address}	matches the tunnel source at the opposite end of the
		tunnel.

Cisco IOS IP Configuration Guide

IPC-443