1、R5为ISP，只能进行ip地址配置；其所有接口配置为公有ip地址
2、R1与R5间使用PPP的PAP认证，R5为主认证方；R2与R5间使用PPP的chap认证，R5为主认证方；R3与R5间使用HDLC封装
3、R1/2/3构建一个MGRE环境，R1为中心站点；R1/4间为点到点GRE
4、整个私有网络基于RIP全网可达
5、所有路由器基于环回私有地址为源ip时，可以正常访问R5环回
分析：
1.建立连接
2、进行IP地址的配置
3、在R1和R5使用PPP进行PAP认证
[R5]aaa
[R5-aaa]local-user huawei password cipher huawei123
Info: Add a new user.
[R5-aaa]local-user huawei service-type ppp
[R5-aaa]q
[R5]int s3/0/0
[R5-Serial3/0/0]link-protocol ppp
[R5-Serial3/0/0]ppp authentication-mode pap
被认证端
[R1-rip-1]int s4/0/0
[R1-Serial4/0/0]link-protocol ppp
[R1-Serial4/0/0]ppp pap local-user huawei password cipher huawei123
4、在R2和R5间使用PPP的chap认证
[R5]aaa
[R5-aaa]local-user nicole password cipher nicole123
Info: Add a new user.
[R5-aaa]local-user nicole service-type ppp
[R5-aaa]int s3/0/1
[R5-Serial3/0/1]link-protocol ppp
[R5-Serial3/0/1]ppp authentication-mode chap
被认证方
[R2]int s4/0/0
[R2-Serial4/0/0]link-protocol ppp
[R2-Serial4/0/0]ppp chap user nicole
[R2-Serial4/0/0]ppp chap password cipher nicole123
5.R3与R5间使用HDLC封装
[R5]int Serial 2/0/0
[R5-Serial2/0/0]lin
[R5-Serial2/0/0]link-protocol hdlc
Warning: The encapsulation protocol of the link will be changed. Continue? [Y/N]
:y
Sep 13 2021 15:07:51-08:00 R5 %%01IFNET/4/CHANGE_ENCAP(l)[0]:The user performed
the configuration that will change the encapsulation protocol of the link and th
en selected Y.
[R3]int s4/0/0
[R3-Serial4/0/0]link-protocol hdlc
Warning: The encapsulation protocol of the link will be changed. Continue? [Y/N]
:y
Sep 13 2021 15:08:37-08:00 R3 %%01IFNET/4/CHANGE_ENCAP(l)[0]:The user performed
the configuration that will change the encapsulation protocol of the link and th
en selected Y.
6、R1/2/3构建一个MGRE环境，R1为中心站点
[R1]int Tunnel 0/0/0
[R1-Tunnel0/0/0]ip address 10.1.1.1 24
[R1-Tunnel0/0/0]tunnel-protocol gre p2mp
[R1-Tunnel0/0/0]source 15.1.1.2
[R1-Tunnel0/0/0]nhrp entry multicast dynamic
[R1-Tunnel0/0/0]nhrp network-id 100
分支：R2
[R2]int Tunnel 0/0/0
[R2-Tunnel0/0/0]ip address 10.1.1.2 24
[R2-Tunnel0/0/0]tunnel-protocol gre p2mp
[R2-Tunnel0/0/0]source s4/0/0
[R2-Tunnel0/0/0]nhrp network-id 100
[R2-Tunnel0/0/0]nhrp entry 10.1.1.1 15.1.1.2 register
分支：R3
[R3]int Tunnel 0/0/0
[R3-Tunnel0/0/0]ip address 10.1.1.3 24
[R3-Tunnel0/0/0]tunnel-protocol gre p2mp
[R3-Tunnel0/0/0]source s4/0/0
[R3-Tunnel0/0/0]nhrp network-id 100
[R3-Tunnel0/0/0]nhrp entry 10.1.1.1 15.1.1.2 register
别忘记进行静态IP配置
[R1]ip route-static 25.1.1.0 24 15.1.1.1
[R1]ip route-static 35.1.1.0 24 15.1.1.1
[R2]ip route-static 15.1.1.0 24 25.1.1.1
[R2]ip route-static 35.1.1.0 24 25.1.1.1
[R3]ip route-static 15.1.1.0 24 35.1.1.1
[R3]ip route-static 5.1.1.0 24 35.1.1.12
7.在R1/4间为点到点GRE
[R1]interface Tunnel 0/0/1
[R1-Tunnel0/0/1]ip address 172.168.1.1 24
[R1-Tunnel0/0/1]tunnel-protocol gre
[R1-Tunnel0/0/1]source 15.1.1.2
[R1-Tunnel0/0/1]destination 45.1.1.2
[R4]int Tunnel 0/0/1
[R4-Tunnel0/0/1]ip address 172.168.1.2 24
[R4-Tunnel0/0/1]tunnel-protocol gre
[R4-Tunnel0/0/1]source 45.1.1.2
[R4-Tunnel0/0/1]destination 15.1.1.2
配静态
[R4]ip route-static 15.1.1.0 24 45.1.1.1
[R1]ip route-static 45.1.1.0 24 15.1.1.1
8、整个私有网络RIP可达
1）宣布直连网段RIP
[R1]rip 1
[R1-rip-1]version 2
[R1-rip-1]undo sum
[R1-rip-1]undo summary
[R1-rip-1]net 192.168.1.0
[R1-rip-1]net 10.0.0.0
[R2]rip 1
[R2-rip-1]version 2
[R2-rip-1]undo sum
[R2-rip-1]undo summary
[R2-rip-1]net 192.168.2.0
[R2-rip-1]net 10.0.0.0
[R3]rip 1
[R3-rip-1]version 2
[R3-rip-1]undo sum
[R3-rip-1]undo summary
[R3-rip-1]net 192.168.3.0
[R3-rip-1]net 10.0.0.0
[R4]rip 1
[R4-rip-1]version 2
[R4-rip-1]undo summary
[R4-rip-1]net 192.168.4.0
[R4-rip-1]net 10.0.0.0
打破水平分割
[R4-Tunnel0/0/0]rip split-honrizon
2）抓取流量(略)
9.所有路由器基于环回私有地址为源ip时，可以正常访问R5环回
加一个缺省路由
[R1]ip route-static 0.0.0.0 0 15.1.1.1
[R2]ip route-static 0.0.0.0 0 25.1.1.1
[R3]ip route-static 0.0.0.0 0 35.1.1.1
[R4]ip route-static 0.0.0.0 0 45.1.1.1