Title

The Multicast Source Discovery Protocol (MSDP) Cisco ACI 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

Verify that the loopback interface is used as the source address for all MSDP packets generated by the router. 1. Navigate to Fabric >> Fabric Policies >> Policies >> Pod >> Management Access on the APIC GUI to find the relevant settings. 2. Verify the loopback interface IP address is used as the source address. If the router does not use its loopback address as the source address when originating MSDP traffic, this is a finding.

Fix Text

Configure the router to use its loopback address is used as the source address when sending MSDP packets. 1. Navigate to Fabric >> Fabric Policies >> Policies >> Pod >> Management Access to find the relevant settings. 2. Specify the loopback interface IP address as the source address.

Additional Identifiers

Rule ID: SV-272099r1064607_rule

Vulnerability ID: V-272099

Group Title: SRG-NET-000512-RTR-000011

Expert Comments

CCIs tied to check.

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