Router R3 :
Router>enable
Router#conf
t
Enter
configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname
R3
R3(config)#interface
gigabitEthernet 0/0
R3(config-if)#ip
address 172.16.2.1 255.255.255.0
R3(config-if)#no
shutdown
R3(config-if)#exit
R3(config)#interface
serial 0/0/0
R3(config-if)#ip
address 192.168.10.9 255.255.255.252
R3(config-if)#no
shutdown
R3(config-if)#exit
R3(config)#interface
serial 0/0/1
R3(config-if)#ip
address 172.16.3.1 255.255.255.252
R3(config-if)#no shutdown
R3(config)#router
ospf 10
R3(config-router)#router-id
3.3.3.3
R3(config-router)#network
172.16.2.0 0.0.0.255 area 0
R3(config-router)#network
192.168.10.8 0.0.0.3 area 0
R3(config-router)#network
172.16.3.0 0.0.0.3 area 0
R3(config-router)#passive-interface gigabitEthernet 0/0
Router R2 :
Router>ENable
Router#CONF
T
Router(config)#hostname
R2
R2(config)#interface
gigabitEthernet 0/0
R2(config-if)#ip
address 192.168.1.1 255.255.255.0
R2(config-if)#no
shutdown
R2(config-if)#exit
R2(config)#interface
serial 0/0/0
R2(config-if)#ip
address 192.168.10.10 255.255.255.252
R2(config-if)#no
shutdown
R2(config-if)#exit
R2(config)#interface
serial 0/0/1
R2(config-if)#ip
address 192.168.10.5 255.255.255.252
R2(config-if)#no shutdown
R2(config)#router
ospf 10
R2(config-router)#router-id
2.2.2.2
R2(config-router)#network
192.168.1.0 0.0.0.255 area 0
R2(config-router)#network
192.168.10.8 0.0.0.3 area 0
R2(config-router)#network
192.168.10.4 0.0.0.3 area 0
R2(config-router)#passive-interface
gigabitEthernet 0/0
R2(config-router)#
Router R1 :
Router>ENable
Router#CONF T
Router(config)#Hostname R1
R1(config)#interface
gigabitEthernet 0/0
R1(config-if)#ip address 172.16.1.1
255.255.255.0
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface serial 0/0/0
R1(config-if)#ip address 172.16.3.2
255.255.255.252
R1(config-if)#no shutdown
R1(config)#exit
R1(config)#interface serial 0/0/1
R1(config-if)#ip address
192.168.10.6 255.255.255.252
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface serial 0/1/0
R1(config-if)#ip address
209.116.104.1 255.255.255.252
R1(config-if)#no shutdown
R1(config)#router
ospf 10
R1(config-router)#router-id
1.1.1.1
R1(config-router)#network
172.16.1.0 0.0.0.255 area 0
R1(config-router)#network
172.16.3.0 0.0.0.3 area 0
R1(config-router)#network 192.168.10.4 0.0.0.3 area 0
R1(config-router)#passive-interface gigabitEthernet 0/0
R1(config)#ip
route 0.0.0.0 0.0.0.0 serial 0/1/0
R1(config)#router ospf 10
R1(config-router)#default-information originate
Router ext :
Router>enable
Router#conf
t
Router(config)#hostname
Rext
Rext(config)#interface
gigabitEthernet 0/0
Rext(config-if)#ip
address 5.5.5.1 255.255.255.0
Rext(config-if)#no
shutdown
Rext(config-if)#exit
Rext(config)#interface
serial 0/0/0
Rext(config-if)#ip
address 209.116.104.2 255.255.255.252
Rext(config-if)#no
shutdown
Rext(config-if)#exit
Rext(config)#ip route 0.0.0.0 0.0.0.0 serial 0/0/0
