R2#
interface Loopback0
 ip address 223.254.254.254 255.255.255.255
!
ip pim rp-candidate Loopback0 interval 10
ip msdp peer 180.40.7.129 connect-source FastEthernet0/1
ip msdp originator-id FastEthernet0/1
!

R3#
interface Loopback0
 ip address 223.254.254.254 255.255.255.255
!
ip pim rp-candidate Loopback0 interval 10
ip msdp peer 180.40.7.98 connect-source FastEthernet0/1
ip msdp originator-id FastEthernet0/1
!