The Cisco ACI multicast rendezvous point (RP) must be configured to filter Protocol Independent Multicast (PIM) Register messages received from the designated router (DR) for any undesirable multicast groups and sources.

Real-time multicast traffic can entail multiple large flows of data. An attacker can flood a network segment with multicast packets, over-using the available bandwidth and thereby creating a denial-of-service (DoS) condition. Hence, it is imperative that register messages are accepted only for authorized multicast groups and sources.

By configuring route maps, the distribution of RP information that is distributed throughout the network can be controlled. Specify the BSRs or mapping agents to be listened to on each client router and the list of candidates to be advertised (listened to) on each BSR and mapping agent to ensure that what is advertised is what is expected.