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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter25 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 fr om 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 thi s switch is not an RP,
it would not have an RP address to use i n a n S A me ssag e. The re fore , thi s com mand pro vi des t he R P
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 de termines 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.
Step5 show running-config Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 ip msdp originator-id type number Configures the RP address in SA messages to be the addres s of the
originating device interface.
For type number, specify the interface type and number on the local
switch.
Step3 end Return to privileged EXEC mode.
Step4 show running-config Verify your entries.
Step5 copy running-config startup-config (Optional) Save your entries in the configuration file.