CISC-RT-000860 - The Cisco multicast Designated Router (DR) must be configured to filter the Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Report messages to allow hosts to join only multicast groups that have been approved by the organization.

Information

Real-time multicast traffic can entail multiple large flows of data. Large unicast flows tend to be fairly isolated (i.e., someone doing a file download here or there), whereas multicast can have broader impact on bandwidth consumption, resulting in extreme network congestion. Hence, it is imperative that there is multicast admission control to restrict which multicast groups hosts are allowed to join via IGMP or MLD.

Solution

Configure the DR to filter the IGMP or MLD Membership Report messages to allow hosts to join only those multicast groups that have been approved.

Step 1: Configure the ACL to filter IGMP Membership Report messages as shown in the example.

R3(config)#ip access-list standard IGMP_JOIN_FILTER
R3(config-std-nacl)#deny 239.8.0.0 0.0.255.255
R3(config-std-nacl)#permit any
R3(config-std-nacl)#exit

Step 2: Apply the filter to all host facing interfaces.

R3(config)#int g0/0
R3(config-if)#ip igmp access-group IGMP_JOIN_FILTER

Item Details

Audit Name: DISA Cisco IOS XE Router RTR STIG v3r5

Category: SYSTEM AND COMMUNICATIONS PROTECTION

Plugin: Cisco

Control ID: 25250e662f5900233384c1627f0e2322dd9bb02e7e036c50fbf31463c6004af0

Detections

Analytics

CISC-RT-000860 - The Cisco multicast Designated Router (DR) must be configured to filter the Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Report messages to allow hosts to join only multicast groups that have been approved by the organization.

Information

Solution

See Also

Item Details