The Cisco Multicast Source Discovery Protocol (MSDP) router must be configured to use a loopback address as the source address when originating MSDP traffic.

Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of MSDP routers.

It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces.

Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses.

Verify that the loopback interface is used as the source address for all MSDP packets generated by the router.

router msdp connect-source Loopback0

If the router does not use its loopback address as the source address when originating MSDP traffic, this is a finding.

Configure the router to use its loopback address is used as the source address when sending MSDP packets.

RP/0/0/CPU0:R2(config)#router msdp RP/0/0/CPU0:R2(config-msdp)#connect-source lo0 RP/0/0/CPU0:R2(config-msdp)#end