要求：
1、R5为ISP,只能进行IP地址配置，其所有地址均配为公有IP地址;
2、R1和R5间使用Ppp的PAP认证，R5为主认证方;
R2与R5之间使用ppp的CHAP认证，R5为主认证方;
R3与R5之间使用HDLC封装;
3、R1、R2: R3构建H个MGRE环境，R1为中心站点，R1、R4间为点到点的GRE;
4、整个私有网络基本RIP全网可达;
5、所有Pc设置私有IP为源IP,可以访问R5环回。
配置：
配置IP地址：
[R1]interface GigabitEthernet 0/0/0
[R1-GigabitEthernet0/0/0]ip address 192.168.1.1 24
[R1]interface Serial 4/0/0
[R1-Serial4/0/0]ip address 15.1.1.1 24
[R2]interface Serial 4/0/0
[R2-Serial4/0/0]ip address 25.1.1.1 24
[R2]interface GigabitEthernet 0/0/0
[R2-GigabitEthernet0/0/0]ip address 192.168.2.1 24
[R3]interface Serial 4/0/0
[R3-Serial4/0/0]ip address 35.1.1.1 24
[R3]interface GigabitEthernet 0/0/0
[R3-GigabitEthernet0/0/0]ip address 192.168.3.1 24
[R4]interface GigabitEthernet 0/0/0
[R4-GigabitEthernet0/0/0]ip address 45.1.1.1 24
[R4]interface GigabitEthernet 0/0/1
[R4-GigabitEthernet0/0/1]ip address 192.168.4.1 24
[R5]interface Serial 4/0/1
[R5-Serial4/0/1]ip address 15.1.1.2 24
[R5]interface Serial 3/0/1
[R5-Serial3/0/1]ip address 25.1.1.2 24
[R5]interface Serial 4/0/0
[R5-Serial4/0/0]ip address 35.1.1.2 24
[R5]interface GigabitEthernet 0/0/0
[R5-GigabitEthernet0/0/0]ip address 45.1.1.2 24
[R5]interface LoopBack 0
[R5-LoopBack0]ip address 5.5.5.5 24
配置静态路由，实现公网通：
[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
配置ppp认证：
[R5]aaa
[R5-aaa]local-user kebi privilege level 15 password cipher kebi1234
[R5-aaa]local-user kebi service-type ppp
[R5]interface Serial 4/0/1
[R5-Serial4/0/1]ppp authentication-mode pap
[R1]interface Serial 4/0/0
[R1-Serial4/0/0]ppp pap local-user kebi passwordcipher kebi1234
[R2]interface Serial 4/0/0
[R2-Serial4/0/0]ppp chap user kebi
[R2-Serial4/0/0]ppp chap passwordcipher kebi1234
HDLC封装
[R3]interface Serial 4/0/0
[R3-Serial4/0/0]link-protocol hdlc
[R5]interface Serial 4/0/0
[R5-Serial4/0/0]link-protocol hdlc
配置gre：
[R1]interface Tunnel 0/0/1
[R1-Tunnel0/0/0]ip address 10.1.1.1 24
[R1-Tunnel0/0/0]tunnel-protocol gre
[R1-Tunnel0/0/0]source 15.1.1.1
[R1-Tunnel0/0/0]destination 45.1.1.1
[R4]interface Tunnel 0/0/1
[R4-Tunnel0/0/0]ip address 10.1.1.2 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
配置mgre：
[R1]interface Tunnel 0/0/0
[R1-Tunnel0/0/0]ip address 10.1.2.1 24
[R1-Tunnel0/0/0]tunnel-protocol gre p2mp
[R1-Tunnel0/0/0]source 15.1.1.1
[R2]interface Tunnel 0/0/0
[R2-Tunnel0/0/0]ip address 10.1.2.2 24
[R2-Tunnel0/0/0]tunnel-protocol gre p2mp
[R2-Tunnel0/0/0]source Serial 4/0/0
[R3]interface Tunnel 0/0/0
[R3-Tunnel0/0/0]ip address 10.1.2.3 24
[R3-Tunnel0/0/0]tunnel-protocol gre p2mp
[R3-Tunnel0/0/0]source Serial 4/0/0
[R1-Tunnel0/0/0]nhrp network-id 100
[R2-Tunnel0/0/0]nhrp network-id 100
[R2-Tunnel0/0/0]nhrp entry 10.1.2.1 15.1.1.1 register
[R3-Tunnel0/0/0]nhrp network-id 100
[R3-Tunnel0/0/0]nhrp entry 10.1.2.1 15.1.1.1 register
配置RIPv2：
[R1]rip 1
[R1-rip-1]version 2
[R1-rip-1]undo summary
[R1-rip-1]network 192.168.1.0
[R1-rip-1]network 10.0.0.0
[R2]rip 1
[R2-rip-1]version 2
[R1-rip-1]undo summary
[R2-rip-1]network 192.168.2.0
[R2-rip-1]network 10.0.0.0
[R3]rip 1
[R3-rip-1]version 2
[R1-rip-1]undo summary
[R3-rip-1]network 192.168.3.0
[R3-rip-1]network 10.0.0.0
[R4]rip 1
[R4-rip-1]version 2
[R1-rip-1]undo summary
[R4-rip-1]network 192.168.4.0
[R4-rip-1]network 10.0.0.0
[R1-Tunnel0/0/0]nhrp entry multicast dynamic
[R1-Tunnel0/0/0]undo rip split-horizon
[R2-Tunnel0/0/0]undo rip split-horizon
[R3-Tunnel0/0/0]undo rip split-horizon
配置easy ip：
[R1]acl 2000
[R1-acl-basic-2000]rule permit source 192.168.1.0 0.0.0.255
[R1]interface 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]interface Serial 4/0/0
[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]interface Serial 4/0/0
[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]interface GigabitEthernet 0/0/1
[R4-GigabitEthernet0/0/1]nat outbound 2000
