CISC-RT-000860 - The Cisco multicast Designated switch (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 group's 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 multicast groups that have been approved.

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

SW2(config)#ip access-list standard IGMP_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

Step 2: Apply the filter to all host-facing Layer 3 and VLAN interfaces.

SW2(config)#int vlan3
SW2(config-if)#ip igmp access-group IGMP_JOIN_FILTER

Item Details

Audit Name: DISA Cisco IOS Switch RTR STIG v3r3

Category: SYSTEM AND COMMUNICATIONS PROTECTION

Plugin: Cisco

Control ID: b0c93f0db249c917d3c3b31a6cee49d123ade9f57b989464d5c4f8c5e29bc3b2

Detections

Analytics

CISC-RT-000860 - The Cisco multicast Designated switch (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