Title

The multicast Cisco ACI must be configured to bind a Protocol Independent Multicast (PIM) neighbor filter to interfaces that have PIM enabled. (Cat II impact)

Discussion

PIM is a routing protocol used to build multicast distribution trees for forwarding multicast traffic across the network infrastructure. PIM traffic must be limited to only known PIM neighbors by configuring and binding a PIM neighbor filter to those interfaces that have PIM enabled. If a PIM neighbor filter is not applied to those interfaces that have PIM enabled, unauthorized routers can join the PIM domain, discover and use the rendezvous points, and also advertise their rendezvous points into the domain. This can result in a denial of service (DoS) by traffic flooding or result in the unauthorized transfer of data.

Check Content

Step 1: Review the network's multicast topology diagram. Step 2: Review the switch configuration to verify only the PIM interfaces as shown in the multicast topology diagram are enabled for PIM as shown in the example below: Example: configure terminal interface Ethernet1/1 ip pim If a multicast interface is required to support PIM and it is not enabled, this is a finding.

Fix Text

From the CLI, use "ip pim" within the interface configuration on the relevant multicast enabled interfaces. Example: configure terminal interface Ethernet1/1 ip pim

Additional Identifiers

Rule ID: SV-272069r1064579_rule

Vulnerability ID: V-272069

Group Title: SRG-NET-000019-RTR-000004

Expert Comments

CCIs tied to check.

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