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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 25 Configuring MSDP
Configuring MSDP
Note that the ip msdp originator-id global configuration command also identifies an interface type and
number to be used as the RP address. If both the ip msdp border sa-address and the ip msdp
originator-id global configuration commands are configured, the address derived from the ip msdp
originator-id command determines 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-address type number global 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 multilayer switches in an MSDP mesh group.
•
If you have a multilayer 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:
If both the ip msdp border sa-address and the ip msdp originator-id global configuration commands
are configured, the address derived from the ip msdp originator-id command determines the address of
the RP.
To prevent the RP address from being derived in this way, use the no ip msdp originator-id type number
global configuration command.
Step 5
show running-config
Verify your entries.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
ip msdp originator-id type number
Configures the RP address in SA messages to be the address of the
originating device interface.
For type number, specify the interface type and number 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.