实验要求：使用OSPF协议，使各个PC之间能够相互通信
拓扑如下：
配置如下：
R1
enable
configure terminal
interface f0/0
ip address 192.168.1.18 255.255.255.252
no shutdown
interface s0/0/0
ip address 192.168.4.9 255.255.255.252
clock rate 64000
no shutdown
interface s0/0/1
ip address 192.168.4.5 255.255.255.252
clock rate 64000
no shutdown
exit
router ospf 1
network 192.168.4.4 0.0.0.3 area 0
network 192.168.4.8 0.0.0.3 area 0
network 192.168.1.16 0.0.0.3 area 1
R2
enable
configure terminal
interface f0/0
ip address 192.168.1.21 255.255.255.252
no shutdown
interface f0/1
ip address 192.168.4.2 255.255.255.252
no shutdown
interface s0/0/0
ip address 192.168.4.6 255.255.255.252
no shutdown
exit
router ospf 1
network 192.168.4.4 0.0.0.3 area 0
network 192.168.4.0 0.0.0.3 area 0
network 192.168.1.20 0.0.0.3 area 1
R3
enable
configure terminal
interface f0/0
ip address 192.168.1.26 255.255.255.252
no shutdown
interface f0/1
ip address 192.168.4.1 255.255.255.252
no shutdown
interface s0/0/0
ip address 192.168.4.10 255.255.255.252
no shutdown
exit
router ospf 1
network 192.168.4.8 0.0.0.3 area 0
network 192.168.4.0 0.0.0.3 area 0
network 192.168.1.24 0.0.0.3 area 1
R4
enable
configure terminal
interface f0/0
ip address 172.16.3.254 255.255.255.0
no shutdown
interface f0/1
ip address 192.168.1.25 255.255.255.252
no shutdown
exit
router ospf 1
network 192.168.1.24 0.0.0.3 area 1
network 172.16.3.0 0.0.0.255 area 1
R5
enable
configure terminal
interface f0/0
ip address 172.16.1.254 255.255.255.0
no shutdown
interface f0/1
ip address 192.168.1.17 255.255.255.252
no shutdown
exit
router ospf 1
network 192.168.1.16 0.0.0.3 area 1
network 172.16.1.0 0.0.0.255 area 1
R6
enable
configure terminal
interface f0/0
ip address 172.16.2.254 255.255.255.0
no shutdown
interface f0/1
ip address 192.168.1.22 255.255.255.252
no shutdown
exit
router ospf 1
network 192.168.1.20 0.0.0.3 area 1
network 172.16.2.0 0.0.0.255 area 1