The multicast Rendezvous Point (RP) router must be configured to filter Protocol Independent Multicast (PIM) Register messages received from the Designated Router (DR) for any undesirable multicast groups and sources.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
lowV-207118SRG-NET-000019SRG-NET-000019-RTR-000013SV-207118r604135_rule2024-05-285
Description
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.
ℹ️ Check
Verify that the RP router is configured to filter PIM register messages. If the RP router peering with PIM-SM routers is not configured with a PIM import policy to block registration messages for any undesirable multicast groups and sources, this is a finding.
✔️ Fix
Configure the RP router to filter PIM register messages received from a multicast DR for any undesirable multicast groups or sources.