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 and MLD report messages to allow hosts to join only those multicast groups from sources that have been approved.
OS10(config)# ip access-list IGMP_FILTER
OS10(config-ipv4-acl)# deny 2 224.0.0.22 239.8.0.0/16 ttl eq 1
OS10(config-ipv4-acl)# permit 2 224.0.0.0/24 238.5.0.0/16
OS10(config-ipv4-acl)# permit ip any any
OS10(config)# interface vlan 100
OS10(conf-if-vl-100)# ip access-group IGMP_FILTER in