On all routers except R4 R1#sh run | b ip mu ip multicast-routing ! ! interface FastEthernet0/0 ip address 17.57.100.1 255.255.255.0 ip pim sparse-dense-mode speed auto half-duplex ! interface Serial0/0.1 point-to-point ip address 180.40.7.34 255.255.255.224 ip pim sparse-dense-mode ip ospf network point-to-multipoint frame-relay interface-dlci 103 ! interface Serial0/0.2 point-to-point ip address 180.40.7.66 255.255.255.224 ip pim sparse-dense-mode ip ospf network point-to-point frame-relay interface-dlci 102 ! interface FastEthernet0/1 ip address 17.100.1.1 255.255.255.0 ip pim sparse-dense-mode speed auto half-duplex no keepalive ! R4#sh run | b ip mu ip multicast-routing ! ! interface FastEthernet0/0 ip address 180.40.7.130 255.255.255.224 ip pim dense-mode ip igmp join-group 224.4.4.4 duplex auto speed auto !