根据拓扑图上的IP地址进行接口IP地址配置和设备名称，并配置OSPF路由，使各路由器能连通。

左侧R1
en
conf t
hostname R1
int g0/0
ip add 10.1.1.1 255.255.255.0
no shut
int g0/1
ip add 172.16.1.1 255.255.255.0
no shut
int s0/0/0
ip add 192.168.12.1 255.255.255.0
clo r 4000000
no shut
exit
router ospf 1
net 10.1.1.1 0.0.0.0 ar 0
net 172.16.1.1 0.0.0.0 ar 0
net 192.168.12.1 0.0.0.0 ar0
中间的：
en
conf t
hostname R2
int s0/0/0
ip add 192.168.12.2 255.255.255.0
clo r 4000000
no shut
int s0/0/1
ip add 192.168.23.2 255.255.255.0
clo r 4000000
no shut
int lo 0
ip add 2.2.2.2 255.255.255.0
no shut
exit
router ospf 1
net 192.168.12.2 0.0.0.0 ar 0
net 192.168.23.2 0.0.0.0 ar 0
net 2.2.2.2 0.0.0.0 ar 0
右面的：
en
conf t
hostname R3
int s0/0/1
ip add 192.168.23.3 255.255.255.0
clo ra 4000000
no shut
int g0/0
ip add 172.16.3.3 255.255.255.0
no shut
exit
router ospf 1
net 192.168.23.3 0.0.0.0 ar 0
net 172.16.3.3 0.0.0.0 ar 0