The configuration for this sample OSPF configuration would look like:
...
interface GigabitEthernet1/1
no shutdown
ip address 172.18.1.13
ip OSPF message-digest-key 109 md5 2router1
ip OSPF authentication message-digest
!
interface GigabitEthernet1/2
no shutdown
ip address 172.18.1.17
ip OSPF message-digest-key 109 md5 2router2
ip OSPF authentication message-digest
!
interface GigabitEthernet1/3
no shutdown
ip address 172.18.1.9
ip OSPF message-digest-key 109 md5 2router3
ip OSPF authentication message-digest
!
interface GigabitEthernet1/4
no shutdown
ip address 172.18.1.5
ip OSPF message-digest-key 109 md5 2router4
ip OSPF authentication message-digest
!
...
router OSPF 100
area 0.0.0.0 stubhost 4.4.4.4 cost 100
network 172.18.1.12 255.255.255.252 area 0.0.0.0
network 172.18.1.16 255.255.255.252 area 0.0.0.0
network 172.18.1.8 255.255.255.252 area 0.0.0.1
network 172.18.1.4 255.255.255.252 area 0.0.0.1
ip route 0.0.0.0 0.0.0.0 172.17.4.1
ip router-id 10.10.10.4
...
OSPF Configuration
OSPF Configuration Example
13-17