R1#sh run | b ip mul
ip multicast-routing   <-----------------------
ip cef
!
!
interface Ethernet0/0
 ip address 17.57.100.1 255.255.255.0
 ip pim sparse-dense-mode   <-----------------------
 half-duplex
!
interface Serial0/0
 no ip address
 encapsulation frame-relay
!
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-point
 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-multipoint
 frame-relay interface-dlci 102
!
interface Ethernet0/1
 ip address 17.100.1.1 255.255.255.0
 ip pim sparse-dense-mode   <-----------------------
 half-duplex
 no keepalive
!


R4#sh run | b ip mul
ip multicast-routing
ip audit po max-events 100
!
!
!
interface FastEthernet0/0
 ip address 180.40.7.130 255.255.255.224
 ip nat inside
 ip pim dense-mode
 ip igmp join-group 224.4.4.4
 duplex auto
 speed auto
!