Detections
Analytics
CISC-RT-000840 - The Cisco multicast Rendezvous Point (RP) switch must be configured to filter Protocol Independent Multicast (PIM) Join messages received from the Designated Cisco switch (DR) for any undesirable multicast groups.
Information
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 join messages are only accepted for authorized multicast groups.Solution
Configure the RP to filter PIM join messages for any undesirable multicast groups as shown in the example below:SW2(config)#ip access-list standard PIM_JOIN_FILTER
SW2(config-std-nacl)#deny 239.8.0.0 0.0.255.255
SW2(config-std-nacl)#permit any
SW2(config-std-nacl)#exit
SW2(config)#ip pim accept-rp 10.2.2.2 PIM_JOIN_FILTER
SW2(config)#end
See Also
https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Cisco_IOS-XE_Switch_Y26M04_STIG.zip
Item Details
Audit Name: DISA Cisco IOS XE Switch RTR STIG v3r4
Category: ACCESS CONTROL
References: 800-53|AC-4, CAT|III, CCI|CCI-001414, Rule-ID|SV-221058r1137932_rule, STIG-ID|CISC-RT-000840, STIG-Legacy|SV-110937, STIG-Legacy|V-101833, Vuln-ID|V-221058
Plugin: Cisco
Control ID: 08883cab09b9f90deed6303b14cbb017f36c8fea2121994b01e1a9d4616cc667