hostname R2
!
ip multicast-routing
!
interface Loopback102
 ip pim sparse-dense-mode
 ip igmp join-group 239.255.1.1
!
interface FastEthernet0/0
 ip pim sparse-dense-mode
!
interface Serial0/0/0
interface Serial0/0/0.124 point-to-point
 ip pim sparse-dense-mode
 ip ospf network point-to-multipoint
!
router ospf 1
 router-id 2.2.2.2
 log-adjacency-changes
 network 172.16.0.0 0.0.255.255 area 0