R1
int fa0/0
ip add 192.168.12.1 255.255.255.0
no sh
int fa1/0
ip add 192.168.14.1 255.255.255.0
no sh
int l 0
ip add 1.1.1.1 255.255.255.0
exit
router os 1
ro-id 1.1.1.1
net 192.168.12.1 0.0.0.0 a 0
net 1.1.1.1 0.0.0.0 a 0
net 192.168.14.1 0.0.0.0 a 1
area 1 vir 4.4.4.4
R2
int fa0/0
ip add 192.168.12.2 255.255.255.0
no sh
int fa1/0
ip add 192.168.23.2 255.255.255.0
no sh
int l 0
ip add 2.2.2.2 255.255.255.0
exit
router os 1
ro-id 2.2.2.2
net 192.168.12.2 0.0.0.0 a 0
net 2.2.2.2 0.0.0.0 a 0
net 192.168.23.2 0.0.0.0 a 2
area 2 vir 3.3.3.3
R3
int fa0/0
ip add 192.168.34.3 255.255.255.0
no sh
int fa1/0
ip add 192.168.23.3 255.255.255.0
no sh
int l 0
ip add 3.3.3.3 255.255.255.0
exit
router os 1
ro-id 3.3.3.3
net 192.168.23.3 0.0.0.0 a 2
net 3.3.3.3 0.0.0.0 a 2
net 192.168.34.3 0.0.0.0 a 3
area 2 vir 2.2.2.2
R4
int fa0/0
ip add 192.168.34.4 255.255.255.0
no sh
int fa1/0
ip add 192.168.14.4 255.255.255.0
no sh
int l 0
ip add 4.4.4.4 255.255.255.0
exit
router os 1
ro-id 4.4.4.4
net 192.168.14.4 0.0.0.0 a 1
net 4.4.4.4 0.0.0.0 a 1
net 192.168.34.4 0.0.0.0 a 3
area 1 vir 1.1.1.1