第一步：在r5上配置环回和s3/0/0接口地址，及pap认证（主认证）

[r5]int lo0
[r5-LoopBack0]ip add 5.5.5.5 24
[r5-LoopBack0]q
[r5]aaa
[r5-aaa]local-user a privilege level 15 password cipher 123456
[r5-aaa]local-user a service-type ppp
[r5-aaa]q
[r5]int s3/0/0
[r5-Serial3/0/0]ip add 15.1.1.2 24
[r5-Serial3/0/0]ppp authentication-mode pap 

第二步：在r1上配置接口，pap认证（被认证方）

[r1]int g0/0/0
[r1-GigabitEthernet0/0/0]ip add 192.168.1.1 24
[r1-GigabitEthernet0/0/0]q
[r1]int s4/0/0
[r1-Serial4/0/0]ppp pap local-user a password cipher 123456
[r1-Serial4/0/0]ip add 15.1.1.1 24 

第三步：在r5上配置s3/0/1接口，chap认证（主认证）

[r5]aaa
[r5-aaa]local-user b privilege level 15 password cipher 123456
[r5-aaa]local-user b service-type ppp
[r5-aaa]q
[r5]int s3/0/1
[r5-Serial3/0/1]ip add 25.1.1.2 24
[r5-Serial3/0/1]ppp authentication-mode chap 

第四步：在r2上配置接口，chap认证（被认证方）

[r2]int g0/0/0
[r2-GigabitEthernet0/0/0]ip add 192.168.2.1 24
[r2-GigabitEthernet0/0/0]int s4/0/0
[r2-Serial4/0/0]ip add 25.1.1.1 24
[r2-Serial4/0/0]ppp chap user b
[r2-Serial4/0/0]ppp chap password cipher 123456

第五步：在r5上配置s4/0/0接口，以及HDLC封装

[r5]int s4/0/0
[r5-Serial4/0/0]ip add 35.1.1.2 24
[r5-Serial4/0/0]link-protocol hdlc 

第六步：在R3上配置接口，以及HDLC封装

[r3]int g0/0/0
[r3-GigabitEthernet0/0/0]ip add 192.168.3.1 24
[r3-GigabitEthernet0/0/0]q
[r3]int s4/0/0
[r3-Serial4/0/0]ip add 35.1.1.1 24
[r3-Serial4/0/0]link-protocol hdlc 

第七步：配置r5的g0/0/0和r4的接口

[r5]int g0/0/0
[r5-GigabitEthernet0/0/0]ip add 45.1.1.2  24

[r4]int g0/0/2
[r4-GigabitEthernet0/0/2]ip add 45.1.1.1 24
[r4-GigabitEthernet0/0/2]q
[r4]int g0/0/0
[r4-GigabitEthernet0/0/0]ip add 192.168.4.1 24

第八步：做缺省路由

[r1]ip route-static 0.0.0.0 0 15.1.1.2

[r2]ip route-static 0.0.0.0 0 25.1.1.2

[r3]ip route-static 0.0.0.0 0 35.1.1.2

[r4]ip route-static 0.0.0.0 0 45.1.1.2

第九步：分别创建MGRE，并在r1上创建中心站点

[r1]interface t	
[r1]interface Tunnel 0/0/0
[r1-Tunnel0/0/0]ip add 10.1.1.1 24
[r1-Tunnel0/0/0]tunnel-protocol gre p2mp 
[r1-Tunnel0/0/0]source 15.1.1.1
[r1-Tunnel0/0/0]nhrp entry multicast dynamic 
[r1-Tunnel0/0/0]nhrp network-id 100

[r2]interface Tunnel 0/0/0
[r2-Tunnel0/0/0] ip add 10.1.1.2 24
[r2-Tunnel0/0/0]tunnel-protocol gre p2mp 
[r2-Tunnel0/0/0]source Serial 4/0/0
[r2-Tunnel0/0/0]nhrp entry 10.1.1.1 15.1.1.1 register 
向r1注册，r1私有ip10.1.1.1，公有ip15.1.1.1
[r2-Tunnel0/0/0]nhrp network-id 100

[r3]interface Tunnel 0/0/0
[r3-Tunnel0/0/0]ip add 10.1.1.3 24
[r3-Tunnel0/0/0]tunnel-protocol gre p2mp 
[r3-Tunnel0/0/0]source Serial 4/0/0
[r3-Tunnel0/0/0]nhrp entry 10.1.1.1 15.1.1.1 register 
[r3-Tunnel0/0/0]nhrp network-id 100

第十步：在r1、r4上创建GRE

[r1]interface Tunnel 0/0/1
[r1-Tunnel0/0/1]ip add 10.1.2.1 24
[r1-Tunnel0/0/1]tunnel-protocol gre 
[r1-Tunnel0/0/1]source 15.1.1.1
[r1-Tunnel0/0/1]destination 45.1.1.1

[r4]interface Tunnel 0/0/0
[r4-Tunnel0/0/0]ip add 10.1.2.2 24
[r4-Tunnel0/0/0]tunnel-protocol gre 
[r4-Tunnel0/0/0]source 45.1.1.1
[r4-Tunnel0/0/0]destination 15.1.1.1

第十步：宣告私网基于rip全网可达

[r1]rip 1
[r1-rip-1]ver 2
[r1-rip-1]network 192.168.1.0
[r1-rip-1]network 10.0.0.0

[r2]rip 1
[r2-rip-1]ver 2
[r2-rip-1]network 10.0.0.0
[r2-rip-1]network 192.168.2.0 

[r3]rip 1
[r3-rip-1]ver 2
[r3-rip-1]network 10.0.0.0
[r3-rip-1]network 192.168.3.0

[r4]rip 1
[r4-rip-1]ver 2
[r4-rip-1]network 10.0.0.0
[r4-rip-1]network 192.168.4.0

第十一步：在r1上关闭水平分割

使得r2可以把数据给r1，r1又可以把数据给r3

[r1]int Tunnel 0/0/0
[r1-Tunnel0/0/0]undo rip split-horizon

第十二步：做个一对多的nat

[r1]acl 2000
[r1-acl-basic-2000]rule permit source 192.168.1.0 0.0.0.255
[r1-acl-basic-2000]q
[r1]int Serial 4/0/0
[r1-Serial4/0/0]nat outbound 2000

[r2]acl 2000
[r2-acl-basic-2000]rule permit source 192.168.2.0 0.0.0.255
[r2-acl-basic-2000]int s4/0/0
[r2-Serial4/0/0]nat outbound 2000

[r3]acl 2000
[r3-acl-basic-2000]rule permit source 192.168.3.0 0.0.0.255
[r3-acl-basic-2000]int s4/0/0
[r3-Serial4/0/0]nat outbound 2000

[r4]acl 2000
[r4-acl-basic-2000]rule permit source 192.168.4.0 0.0.0.255
[r4-acl-basic-2000]int g0/0/2
[r4-GigabitEthernet0/0/2]nat outbound 2000

第十三步：分别用PC机ping 5.5.5.5