iTable of Contents1 Multicast Overview ····································································································································1-1Multicast Overview ··································································································································1-1Information Transmission in the Unicast Mode ···············································································1-1Information Transmission in the Broadcast Mode···········································································1-2Information Transmission in the Multicast Mode·············································································1-3Roles in Multicast ····························································································································1-3Common Notations in Multicast·······································································································1-4Advantages and Applications of Multicast·······················································································1-5Multicast Models ·····································································································································1-5Multicast Architecture······························································································································1-6Multicast Address ····························································································································1-6Multicast Protocols ··························································································································1-9Multicast Packet Forwarding Mechanism ·····························································································1-10Implementation of the RPF Mechanism ························································································1-11RPF Check ····································································································································1-112 Common Multicast Configuration············································································································2-1Common Multicast Configuration············································································································2-1Enabling Multicast Packet Buffering································································································2-1Enabling Multicast Routing··············································································································2-2Configuring Limit on the Number of Route Entries··········································································2-2Configuring Suppression on the Multicast Source Port···································································2-3Clearing Multicast Forwarding and Routing Entries ········································································2-3Configuring a Multicast MAC Address Entry ···················································································2-4Configuring Dropping Unknown Multicast Packets ·········································································2-4Tracing a Multicast Path ··················································································································2-5Displaying and Maintaining Common Multicast Configuration································································2-53 IGMP Configuration ···································································································································3-1IGMP Overview ·······································································································································3-1IGMP Versions ································································································································3-1Work Mechanism of IGMPv1···········································································································3-1Enhancements Provided by IGMPv2 ······························································································3-3Enhancements Provided by IGMPv3 ······························································································3-3IGMP Proxy ·····································································································································3-5Configuring IGMP····································································································································3-6IGMP Configuration Task List ·········································································································3-6Enabling IGMP ································································································································3-6Configuring IGMP Version···············································································································3-7Configuring Options Related to IGMP Query Messages·································································3-7Configuring the Maximum Allowed Number of Multicast Groups····················································3-9Configuring a Multicast Group Filter································································································3-9