router ospf 1
 router-id 1.1.1.1

 network 172.16.10.0 0.0.0.255 area 0

 network 172.16.20.0 0.0.0.255 area 0

 network 172.16.100.0 0.0.0.63 area 0

 network 10.1.3.0 0.0.0.3 area 0

 network 10.1.1.0 0.0.0.3 area 0

end