Title

The Multicast Source Discovery Protocol (MSDP) router must be configured to use its loopback address as the source address when originating MSDP traffic. (Cat III impact)

Discussion

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.

Check Content

Review the router configuration to verify that a loopback address has been configured. Verify that a loopback interface is used as the source address for all MSDP packets generated by the router. If the router does not use its loopback address as the source address when originating MSDP traffic, this is a finding.

Fix Text

Ensure that the router’s loopback address is used as the source address when originating traffic.

Additional Identifiers

Rule ID: SV-207182r604135_rule

Vulnerability ID: V-207182

Group Title: SRG-NET-000512

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.