hostname r4
!
interface Loopback0
 ip address 1.0.0.4 255.255.255.255
 ip ospf 1 area 0
!
interface GigabitEthernet1
 ip address 10.1.4.2 255.255.255.252
 ip ospf network point-to-point
 ip ospf 1 area 0
 negotiation auto
 no shutdown
!
interface GigabitEthernet2
 ip address 10.3.4.2 255.255.255.252
 ip ospf network point-to-point
 ip ospf 1 area 0
 ip ospf cost 100
 negotiation auto
 no shutdown
!
interface GigabitEthernet3
 ip address 10.4.5.1 255.255.255.252
 ip ospf 1 area 0
 ip ospf cost 100
 negotiation auto
 no shutdown
!
end