hostname Hub
!
no ip domain lookup
ip multicast-routing 
ip cef
!
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
 ip pim sparse-mode
!
interface Tunnel0
 ip address 172.16.123.1 255.255.255.0
 no ip redirects
 ip pim sparse-mode
 ip nhrp authentication DMVPN
 ip nhrp map multicast dynamic
 ip nhrp network-id 1
 ip nhrp redirect
 ip ospf network point-to-multipoint
 tunnel source GigabitEthernet0/1
 tunnel mode gre multipoint
!
interface GigabitEthernet0/0
 ip address 10.255.1.27 255.255.0.0
 no cdp enable
!
interface GigabitEthernet0/1
 ip address 192.168.123.1 255.255.255.0
 no cdp enable
!
router ospf 1
 network 1.1.1.1 0.0.0.0 area 0
 network 172.16.123.0 0.0.0.255 area 1
!
ip pim rp-address 1.1.1.1
!
end