hostname xrv1
interface Loopback0
 ipv4 address 1.0.0.1 255.255.255.255
!
interface GigabitEthernet0/0/0/0
 ipv4 address 10.1.2.1 255.255.255.252
 no shutdown
!
interface GigabitEthernet0/0/0/1
 ipv4 address 10.1.3.1 255.255.255.252
 no shutdown
!
interface GigabitEthernet0/0/0/2
 ipv4 address 10.1.4.1 255.255.255.252
 no shutdown
!
interface GigabitEthernet0/0/0/3
 ipv4 address 10.1.5.1 255.255.255.252
 no shutdown
!
router ospf 1
 area 0
  interface Loopback0
  !
  interface GigabitEthernet0/0/0/0
   network point-to-point
  !
  interface GigabitEthernet0/0/0/1
   network point-to-point
  !
  interface GigabitEthernet0/0/0/2
   network point-to-point
  !
  interface GigabitEthernet0/0/0/3
   network point-to-point
  !
 !
!
end