Cisco Systems 3750E manual Configuring an Originating Address other than the RP Address, 43-18

Chapter 43 Configuring MSDP

Configuring MSDP

	Command	Purpose
Step 5
	show running-config	Verify your entries.
Step 6
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

Note that the ip msdp originator-idglobal configuration command also identifies an interface to be used as the RP address. If both the ip msdp border sa-addressand the ip msdp originator-idglobal configuration commands are configured, the address derived from the ip msdp originator-idcommand specifies the RP address.

To return to the default setting (active sources in the dense-mode region do not participate in MSDP), use the no ip msdp border sa-addressinterface-idglobal configuration command.

Configuring an Originating Address other than the RP Address

You can allow an MSDP speaker that originates an SA message to use the IP address of the interface as the RP address in the SA message by changing the Originator ID. You might change the Originator ID in one of these cases:

•If you configure a logical RP on multiple switches in an MSDP mesh group.

•If you have a switch that borders a PIM sparse-mode domain and a dense-mode domain. If a switch borders a dense-mode domain for a site, and sparse-mode is being used externally, you might want dense-mode sources to be known to the outside world. Because this switch is not an RP, it would not have an RP address to use in an SA message. Therefore, this command provides the RP address by specifying the address of the interface.

Beginning in privileged EXEC mode, follow these steps to allow an MSDP speaker that originates an SA message to use the IP address on the interface as the RP address in the SA message. This procedure is optional.

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	ip msdp originator-id interface-id	Configures the RP address in SA messages to be the address of the
		originating device interface.
		For interface-id, specify the interface on the local switch.
Step 3
	end	Return to privileged EXEC mode.
Step 4
	show running-config	Verify your entries.
Step 5
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

If both the ip msdp border sa-addressand the ip msdp originator-idglobal configuration commands are configured, the address derived from the ip msdp originator-idcommand specifies the address of the RP.

To prevent the RP address from being derived in this way, use the no ip msdp originator-idinterface-idglobal configuration command.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
43-18	OL-9775-02