hostname R1
!
interface Loopback101
 ip pim sparse-dense-mode
!
interface Serial0/0/0.124 multipoint
 ip pim nbma-mode
 ip pim sparse-dense-mode
 ip ospf network point-to-multipoint
!
ip pim send-rp-announce Loopback101 scope 1 group-list Only239 interval 1
ip pim send-rp-discovery Loopback101 scope 4
no ip pim dm-fallback