实验要求：
1、R4为ISP，其上只配置IP地址；R4与其他所直连设备间均使用公有IP；
2、R3-R5、R6、R7为MGRE环境，R3为中心站点；
3、整个OSPF环境IP基于172.16.0.0/16划分；除了R12有两个环回，其他路由器均有一个环回IP
4、所有设备均可访问R4的环回；
5、减少LSA的更新量，加快收敛，保障更新安全；
6、全网可达。
配置：
[R1-GigabitEthernet0/0/0]ip address 172.16.33.1 24
[R1-LoopBack0]ip address 172.16.34.1 24
[R2-GigabitEthernet0/0/0]ip address 172.16.33.2 24
[R2-LoopBack0]ip address 172.16.35.2 24
[R3-GigabitEthernet0/0/0]ip address 172.16.33.3 24
[R3-LoopBack0]ip address 172.16.36.3 24
[R3-Serial4/0/0]ip address 34.0.0.3 24
[R4-ISP-GigabitEthernet0/0/0]ip address 47.0.0.4 24
[R4-ISP-Serial3/0/0]ip address 46.0.0.4 24
[R4-ISP-Serial4/0/0]ip address 34.0.0.4 24
[R4-ISP-Serial4/0/1]ip address 45.0.0.4 24
[R4-ISP-LoopBack0]ip address 172.16.2.4 24
[R5-Serial4/0/0]ip address 45.0.0.5 24
[R5-LoopBack0]ip address 172.16.3.5 24
[R6-Serial4/0/0]ip address 46.0.0.6 24
[R6-GigabitEthernet0/0/0]ip address 172.16.65.1 30
[R6-LoopBack0]ip address 172.16.4.6 24
[R7-GigabitEthernet0/0/0]ip address 47.0.0.7 24
[R7-GigabitEthernet0/0/1]ip address 172.16.97.1 30
[R7-LoopBack0]ip address 172.16.5.7 24
[R8-GigabitEthernet0/0/0]ip address 172.16.97.2 30
[R8-GigabitEthernet0/0/1]ip address 172.16.97.5 30
[R8-LoopBack0]ip address 172.16.98.8 24
[R9-GigabitEthernet0/0/0]ip address 172.16.97.6 30
[R9-GigabitEthernet0/0/1]ip address 172.16.129.1 30
[R9-LoopBack0]ip address 172.16.130.9 24
[R10-GigabitEthernet0/0/0]ip address 172.16.129.2 30
[R10-LoopBack0]ip address 172.16.131.10 24
[R11-GigabitEthernet0/0/0]ip address 172.16.65.2 30
[R11-GigabitEthernet0/0/1]ip address 172.16.65.5 30
[R11-LoopBack0]ip address 172.16.66.11 24
[R12-GigabitEthernet0/0/0]ip address 172.16.65.6 30
[R12-LoopBack0]ip address 172.16.160.12 24
[R12-LoopBack1]ip address 172.16.161.12 24
配置OSPF做私网通
[R1]ospf 1 router-id 1.1.1.1
[R1-ospf-1]a 1
[R1-ospf-1-area-0.0.0.1]network 172.16.33.1 0.0.0.0
[R1-ospf-1-area-0.0.0.1]network 172.16.34.1 0.0.0.0
[R2]ospf 1 router-id 2.2.2.2
[R2-ospf-1]a 1
[R2-ospf-1-area-0.0.0.1]network 172.16.33.2 0.0.0.0
[R2-ospf-1-area-0.0.0.1]network 172.16.35.2 0.0.0.0
[R3]ospf 1 router-id 3.3.3.3
[R3-ospf-1]a 1
[R3-ospf-1-area-0.0.0.1]network 172.16.33.3 0.0.0.0
[R3-ospf-1-area-0.0.0.1]network 172.16.36.3 0.0.0.0
[R5]ospf 1 router-id 5.5.5.5
[R5-ospf-1]a 0
[R5-ospf-1-area-0.0.0.0]network 172.16.3.0 0.0.0.255
[R6]ospf 1 router-id 6.6.6.6
[R6-ospf-1]a 0
[R6-ospf-1-area-0.0.0.0]network 172.16.4.0 0.0.0.255
[R7]ospf 1 router-id 7.7.7.7
[R7-ospf-1]a 0
[R7-ospf-1-area-0.0.0.0]network 172.16.5.0 0.0.0.255
[R6]ospf 1 router-id 6.6.6.6
[R6-ospf-1]a 2
[R6-ospf-1-area-0.0.0.2]network 172.16.65.1 0.0.0.0
[R11]ospf 1 router-id 11.11.11.11
[R11-ospf-1]a 2
[R11-ospf-1-area-0.0.0.2]network 172.16.65.2 0.0.0.0
[R11-ospf-1-area-0.0.0.2]network 172.16.65.5 0.0.0.0
[R11-ospf-1-area-0.0.0.2]network 172.16.66.0 0.0.0.255
[R12]ospf 1 router-id 12.12.12.12
[R12-ospf-1]a 2
[R12-ospf-1-area-0.0.0.2]network 172.16.65.6 0.0.0.0
[R12]rip 1
[R12-rip-1]version 2
[R12-rip-1]undo summary
[R12-rip-1]network 172.16.0.0
[R7]ospf 1 router-id 7.7.7.7
[R7-ospf-1]a 3
[R7-ospf-1-area-0.0.0.3]network 172.16.97.1 0.0.0.0
[R8]ospf 1 router-id 8.8.8.8
[R8-ospf-1]a 3
[R8-ospf-1-area-0.0.0.3]network 172.16.97.2 0.0.0.0
[R8-ospf-1-area-0.0.0.3]network 172.16.97.5 0.0.0.0
[R8-ospf-1-area-0.0.0.3]network 172.16.98.8 0.0.0.0
[R9]ospf 1 router-id 9.9.9.9
[R9-ospf-1]a 3
[R9-ospf-1-area-0.0.0.3]network 172.16.97.6 0.0.0.0
[R9-ospf-1]a 4
[R9-ospf-1-area-0.0.0.4]network 172.16.130.0 0.0.0.255
[R9-ospf-1-area-0.0.0.4]network 172.16.129.1 0.0.0.0
[R10]ospf 1 router-id 10.10.10.10
[R10-ospf-1]a 4
[R10-ospf-1-area-0.0.0.4]network 172.16.129.2 0.0.0.0
[R10-ospf-1-area-0.0.0.4]network 172.16.131.0 0.0.0.255
双向路由引入
[R9-ospf-1]a 4
[R9-ospf-1-area-0.0.0.4]undo network 172.16.129.1 0.0.0.0
[R9-ospf-1-area-0.0.0.4]undo network 172.16.130.0 0.0.0.255
[R9-ospf-1]undo a 4
[R9]ospf 2
[R9-ospf-2]a 4
[R9-ospf-2-area-0.0.0.4]network 172.16.129.1 0.0.0.0
[R9-ospf-2-area-0.0.0.4]network 172.16.130.0 0.0.0.255
[R9-ospf-1]import-route ospf 2
[R9-ospf-2]import-route ospf 1
配置MGRE VPN
[R3]interface Tunnel 0/0/0
[R3-Tunnel0/0/0]ip address 172.16.6.3 24
[R3-Tunnel0/0/0]tunnel-protocol gre p2mp
[R3-Tunnel0/0/0]source 34.0.0.3
[R3-Tunnel0/0/0]nhrp network-id 1000
[R3-ospf-1-area-0.0.0.0]network 172.16.6.0 0.0.0.255
[R3-Tunnel0/0/0]nhrp entry multicast dynamic （开启伪广播）
[R3-Tunnel0/0/0]ospf network-type broadcast （修改接口类型）
[R5]interface Tunnel 0/0/0
[R5-Tunnel0/0/0]ip address 172.16.6.5 24
[R5-Tunnel0/0/0]tunnel-protocol gre p2mp
[R5-Tunnel0/0/0]source Serial 4/0/0
[R5-Tunnel0/0/0]nhrp network-id 1000
[R5-Tunnel0/0/0]nhrp entry 172.16.6.3 34.0.0.3 register
[R5-ospf-1-area-0.0.0.0]network 172.16.6.0 0.0.0.255
[R5-Tunnel0/0/0]ospf network-type broadcast
[R5-Tunnel0/0/0]ospf dr-priority 0
[R6]interface Tunnel 0/0/0
[R6-Tunnel0/0/0]ip address 172.16.6.6 24
[R6-Tunnel0/0/0]tunnel-protocol gre p2mp
[R6-Tunnel0/0/0]source Serial 4/0/0
[R6-Tunnel0/0/0]nhrp network-id 1000
[R6-Tunnel0/0/0]nhrp entry 172.16.6.3 34.0.0.3 register
[R6-ospf-1-area-0.0.0.0]network 172.16.6.0 0.0.0.255
[R6-Tunnel0/0/0]ospf network-type broadcast
[R6-Tunnel0/0/0]ospf dr-priority 0
[R7]interface Tunnel 0/0/0
[R7-Tunnel0/0/0]ip address 172.16.6.7 24
[R7-Tunnel0/0/0]tunnel-protocol gre p2mp
[R7-Tunnel0/0/0]source g0/0/0
[R7-Tunnel0/0/0]nhrp network-id 1000
[R7-Tunnel0/0/0]nhrp entry 172.16.6.3 34.0.0.3 register
[R7-ospf-1-area-0.0.0.0]network 172.16.6.0 0.0.0.255
[R7-Tunnel0/0/0]ospf network-type broadcast
[R7-Tunnel0/0/0]ospf dr-priority 0
配置NAT，用作公私网的转换
[R3]acl 2000
[R3-acl-basic-2000]rule permit source 172.16.0.0 0.0.255.255
[R3]interface s4/0/0
[R3-Serial4/0/0]nat outbound 2000
[R5]acl 2000
[R5-acl-basic-2000]rule permit source 172.16.0.0 0.0.255.255
[R5]interface s4/0/0
[R5-Serial4/0/0]nat outbound 2000
[R6]acl 2000
[R6-acl-basic-2000]rule permit source 172.16.0.0 0.0.255.255
[R6]interface s4/0/0
[R6-Serial4/0/0]nat outbound 2000
[R7]acl 2000
[R7-acl-basic-2000]rule permit source 172.16.0.0 0.0.255.255
[R7]interface g0/0/0
[R7-GigabitEthernet0/0/0]nat outbound 2000