hostname rp
!
interface rp-eth0
 ip address 10.0.30.3/24
 ip pim
!
interface lo
  ip address 10.254.0.3/32
  ip pim
!
router pim
  join-prune-interval 5
  rp 10.254.0.3
  register-accept-list ACCEPT

ip prefix-list ACCEPT seq 5 permit 10.0.20.0/24 le 32
