MULTICASTING Key Commands Shows and Debugs R1(config-if) ip igrp join-group 224.1.1.2 R1(config) ip multicast-routing R1(config) ip cgmp Then select multicast routing protocol: For PIM dense mode: R1(config-if) ip pim dense mode Sparse mode: R1(config-if) ip pim sparse-mode R1(config) ip pim rp-address A.B.C.D On Catalyst: Set cgmp enable Set cgmp multicast router <mod/port> Show ip pim interface Show ip pim neighbor Show ip mroute Show ip mroute summary Show ip mroute count Show ip mroute active Show ip igmp group Additional Commands For PIM auto-rp, interface config: ip pim send-rp-announce loopback 0 scope 16 ip pim send-rp-discovery scope 16 Where loopback 0 is the announcing interface, and scope 16 is a TTL of 16 hops. Rp filter: ip pim accept-rp A.B.C.D or group-list 10 Tunnel for multicast only: Interface tunnel 0 Ip unnumbered ethernet 0 Ip pim sparse-mode Tunnel source ethernet 0 Tunnel destination A.B.C.D Tunnel mode DVMRP Over NBMA: (config-if) ip pim nbma-mode Spot The Issue Notes The two steps: 1. Define the ip multicast group to support in your multicast routing with the interface command: "ip igmp join-group 224.10.1.3" 2. Enable IP multicast routing in global configuration mode and define which multicast routing protocol to use. Choices are: • MOSPF • PIM • DVMRP Can PING the multicast address (ex 224.1.1.10) to test multicast reacheability. Can use multiple auto RP machines, but priority goes to the highest advertised ip address (in the case above, would be the ip address on loopback 0 . MULTICASTING Key Commands Shows and Debugs R1(config-if) ip igrp join-group