一、拓扑图

二、实验要求

1，R5为ISP，其上只能配置IP地址;R4作为企业边界路由器，出口公网地址需要通过PPP协议获取，并进行chap认证。

2，整个0SPF环境IP基于172.16.0.8/16划分。

3，所有设备均可访问R5的环回。

4，减少LSA的更新量，加快收敛，保障更新安全。

5，全网可达。

三、配置过程

AR1

[AR1]int g 0/0/0	
[AR1-GigabitEthernet0/0/0]ip address 176.16.1.1 24
[AR1]ospf 1 router-id 1.1.1.1
[AR1-ospf-1]area 0.0.0.1
[AR1-ospf-1-area-0.0.0.1]network 172.16.1.0 0.0.0.255
[AR1-ospf-1-area-0.0.0.1]q

AR2

[AR2]int g 0/0/0
[AR2-GigabitEthernet0/0/0]ip add 172.16.2.1 24
[AR2-GigabitEthernet0/0/0]q
[AR2]ospf 1 router-id 2.2.2.2
[AR2-ospf-1]area 0.0.0.1
[AR2-ospf-1-area-0.0.0.1]network 172.16.2.0 0.0.0.255
[AR2-ospf-1-area-0.0.0.1]q
[AR2-ospf-1]

 AR3

[AR3]int g 0/0/0
[AR3-GigabitEthernet0/0/0]ip add 172.16.3.1 24
[AR3-GigabitEthernet0/0/0]int g 0/0/1
[AR3-GigabitEthernet0/0/1]ip add 172.16.4.1 24
[AR3-GigabitEthernet0/0/1]q
[AR3]ospf 1 router-id 3.3.3.3
[AR3-ospf-1]area 0.0.0.0
[AR3-ospf-1-area-0.0.0.0]network 172.16.3.0 0.0.0.255
[AR3-ospf-1-area-0.0.0.0]network 172.16.4.0 0.0.0.255
[AR3-ospf-1-area-0.0.0.0]area 0.0.0.1
[AR3-ospf-1-area-0.0.0.1]network 172.16.1.0 0.0.0.255

AR4

[AR4]int g 0/0/1
[AR4-GigabitEthernet0/0/1]ip add 172.16.4.2 24
[AR4]int Serial 2/0/0
[AR4-Serial2/0/0]link-protocol ppp
[AR4-Serial2/0/0]ppp chap user ar4	
[AR4-Serial2/0/0]ppp chap password cipher ar4password
[AR4-Serial2/0/0]ip add ppp-negotiate 
[AR4]ospf 1 router-id 4.4.4.4
[AR4-ospf-1]area 0.0.0.0	
[AR4-ospf-1-area-0.0.0.0]network 172.16.4.0 0.0.0.255
[AR4]ip route-static 0.0.0.0 0.0.0.0 Serial 2/0/0
[AR4]

 AR5

[AR5]int Serial 2/0/0
[AR5-Serial2/0/0]ip add 202.100.1.1 24

 AR6

[AR6-GigabitEthernet0/0/1]int g 0/0/0
[AR6-GigabitEthernet0/0/0]ip add 172.16.6.1 24
[AR6-GigabitEthernet0/0/0]q
[AR6]ospf 1 router-id 6.6.6.6
[AR6-ospf-1]area 0.0.0.0	
[AR6-ospf-1-area-0.0.0.0]network 172.16.6.0 0.0.0.255
[AR6-ospf-1-area-0.0.0.0]

AR7

[AR7]int g 0/0/0
[AR7-GigabitEthernet0/0/0]ip add 172.16.7.1 24
[AR7]ospf 1 router-id 7.7.7.7
[AR7-ospf-1]area 0.0.0.0
[AR7-ospf-1-area-0.0.0.0]network 172.16.7.0 0.0.0.255
[AR7-ospf-1-area-0.0.0.0]

 AR8

[AR8]int g 0/0/0
[AR8-GigabitEthernet0/0/0]ip add 172.16.8.1 24
[AR8-GigabitEthernet0/0/0]q
[AR8]ospf 1 router-id 8.8.8.8
[AR8-ospf-1]area 0.0.0.0
[AR8-ospf-1-area-0.0.0.0]network 172.16.8.0 0.0.0.255
[AR8-ospf-1-area-0.0.0.0]

 AR9

[AR9]int g 0/0/0
[AR9-GigabitEthernet0/0/0]ip add 172.16.9.1 24
[AR9-GigabitEthernet0/0/0]q	
[AR9]ospf 1 router-id 9.9.9.9
[AR9-ospf-1]area 0.0.0.0
[AR9-ospf-1-area-0.0.0.0]network 172.16.9.0 0.0.0.255
[AR9-ospf-1-area-0.0.0.0]

AR10

[AR10]int g 0/0/0
[AR10-GigabitEthernet0/0/0]ip add 172.16.10.1 24
[AR10-GigabitEthernet0/0/0]q
[AR10]ospf 1 router-id 10.10.10.10
[AR10-ospf-1]area 0.0.0.0
[AR10-ospf-1-area-0.0.0.0]network 172.16.10.0 0.0.0.255
[AR10-ospf-1-area-0.0.0.0]

AR11

[AR11]int g 0/0/0
[AR11-GigabitEthernet0/0/0]ip add 172.16.11.1 24
[AR11-GigabitEthernet0/0/0]int g 0/0/1
[AR11-GigabitEthernet0/0/1]ip add 172.16.6.2 24
[AR11-GigabitEthernet0/0/1]q
[AR11]ospf 1 router-id 11.11.11.11
[AR11-ospf-1]area 0.0.0.0
[AR11-ospf-1-area-0.0.0.0]network 172.16.11.0 0.0.0.255
[AR11-ospf-1-area-0.0.0.0]network 172.16.6.0 0.0.0.255
[AR11-ospf-1-area-0.0.0.0]

 AR12

[AR12]int g 0/0/0
[AR12-GigabitEthernet0/0/0]ip add 172.16.12.1 24
[AR12]ospf 1 router-id 12.12.12.12
[AR12-ospf-1]area 0.0.0.0
[AR12-ospf-1-area-0.0.0.0]network 172.16.12.0 0.0.0.255
[AR12-ospf-1-area-0.0.0.0]

 配置OSPF的特殊区域

[AR1]ospf 1
[AR1-ospf-1]area 0.0.0.1
[AR1-ospf-1-area-0.0.0.1]stub
[AR1-ospf-1-area-0.0.0.1][AR2]ospf 1 
[AR2-ospf-1]are	
[AR2-ospf-1]area 0.0.0.1
[AR2-ospf-1-area-0.0.0.1]stub
[AR2-ospf-1-area-0.0.0.1][AR3]ospf 1
[AR3-ospf-1]area 0.0.0.1	
[AR3-ospf-1-area-0.0.0.1]stub no-summary 
[AR3-ospf-1-area-0.0.0.1][AR1]int g 0/0/0
[AR1-GigabitEthernet0/0/0]ospf authentication-mode simple cipher 3
[AR1-GigabitEthernet0/0/0][AR3]int g 0/0/0	
[AR3-GigabitEthernet0/0/0]ospf authentication-mode simple cipher 3
[AR3-GigabitEthernet0/0/0]