一、实验拓扑
二、实验需求
1、R6为ISP只能配置ip地址，R1-5的环回为私有网段
2、R1/4/5为全连的MGRE结构，R1/2/3为星型的拓扑结构，R1为中心站点
3、所有私有网段可以互相通讯，私有网段使用OSPF协议完成
三、实验思路
1、R1-R6各个接口配置公网IP地址，配置私有环回网段。
2、公网路由：R1-R5配置指向R6的缺省路由，使得公网可以联通。
3、R1/4/5为全连接MGRE结构，R1/4/5各个tunnel接口源固定公网IP地址。
4、R1/2/3为星型的拓扑结构，R1为中心站点，R1对应tunnel接口源固定公网IP地址，R2和R3tunnel接口源直接声明为该物理接口。
5、R1/2/3开启OFPS协议，宣告，修改OFPS接口网络类型为广播。
6、R1/4/5启OFPS协议，宣告，R2，R3放弃选举，R1作为DR，修改OFPS接口网络类型为广播。
四、实验步骤
一、配置各路由器私有网段、公网接口IP地址
R1
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 10.1.1.1/24 up up
GigabitEthernet0/0/1 11.1.1.1/24 up up
GigabitEthernet0/0/2 unassigned down down
LoopBack0 192.168.1.1/24 up up(s)
NULL0 unassigned up up(s)
R2
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 12.1.1.1/24 up up
GigabitEthernet0/0/1 unassigned down down
GigabitEthernet0/0/2 unassigned down down
LoopBack0 192.168.2.1/24 up up(s)
NULL0 unassigned up up(s)
R3
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 14.1.1.1/24 up up
GigabitEthernet0/0/1 unassigned down down
GigabitEthernet0/0/2 unassigned down down
LoopBack0 192.168.4.1/24 up up(s)
NULL0 unassigned up up(s)
R4
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 13.1.1.1/24 up up
GigabitEthernet0/0/1 unassigned down down
GigabitEthernet0/0/2 unassigned down down
LoopBack0 192.168.3.1/24 up up(s)
NULL0 unassigned up up(s)
R5
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 15.1.1.1/24 up up
GigabitEthernet0/0/1 unassigned down down
GigabitEthernet0/0/2 unassigned down down
LoopBack0 192.168.5.1/24 up up(s)
NULL0 unassigned up up(s)
R6
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 10.1.1.2/24 up up
GigabitEthernet0/0/1 11.1.1.2/24 up up
GigabitEthernet0/0/2 12.1.1.2/24 up up
GigabitEthernet2/0/0 13.1.1.2/24 up up
GigabitEthernet3/0/0 14.1.1.2/24 up up
GigabitEthernet4/0/0 15.1.1.2/24 up up
NULL0 unassigned up up(s)
二、公网路由，R1-R5配置指向R6的缺省路由
[R1]ip route-static 0.0.0.0 0.0.0.0 10.1.1.2
[R1]ip route-static 0.0.0.0 0.0.0.0 11.1.1.2
[R2]ip route-static 0.0.0.0 0.0.0.0 12.1.1.2
[R3]ip route-static 0.0.0.0 0.0.0.0 13.1.1.2
[R4]ip route-static 0.0.0.0 0.0.0.0 14.1.1.2
[R5]ip route-static 0.0.0.0 0.0.0.0 15.1.1.2
此时公网的物理链路可通
三、打通R1，R4，R5之间的tunnel
MGRE的逻辑结构图
R1向R4和R5注册
[R1]int t0/0/1
[R1-Tunnel0/0/1]ip address 192.168.7.1 24
[R1-Tunnel0/0/1]tunnel-protocol gre p2mp
[R1-Tunnel0/0/1]source 11.1.1.1
[R1-Tunnel0/0/1]nhrp entry 192.168.7.2 14.1.1.1 register
[R1-Tunnel0/0/1]nhrp entry 192.168.7.3 15.1.1.1 register
[R1-Tunnel0/0/1]nhrp network-id 101
R4向R5注册
[R4]int t0/0/0
[R4-Tunnel0/0/0]ip address 192.168.7.2 24
[R4-Tunnel0/0/0]tunnel-protocol gre p2mp
[R4-Tunnel0/0/0]source 14.1.1.1
[R4-Tunnel0/0/0]nhrp entry multicast dynamic
[R4-Tunnel0/0/0]nhrp entry 192.168.7.3 15.1.1.1 register
[R4-Tunnel0/0/0]nhrp network-id 101
[R5]int t0/0/0
[R5-Tunnel0/0/0]ip address 192.168.7.3 24
[R5-Tunnel0/0/0]tunnel-protocol gre p2mp
[R5-Tunnel0/0/0]source 15.1.1.1
[R4-Tunnel0/0/0]nhrp entry multicast dynamic
[R5-Tunnel0/0/0]nhrp network-id 101
两两之间的伪广播功能均已开启，R1，R4，R5的MAP均补全
四、打通R1，R2，R3之间的tunnel
R1作为中心站点
[R1]int t0/0/0
[R1-Tunnel0/0/0]ip address 192.168.6.1 24
[R1-Tunnel0/0/0]tunnel-protocol gre p2mp
[R1-Tunnel0/0/0]source 10.1.1.1
[R1-Tunnel0/0/0]nhrp entry multicast dynamic
[R1-Tunnel0/0/0]nhrp network-id 100
R2和R3作为分支站点
[R2]int t0/0/0
[R2-Tunnel0/0/0]ip address 192.168.6.2 24
[R2-Tunnel0/0/0]tunnel-protocol gre p2mp
[R2-Tunnel0/0/0]source GigabitEthernet0/0/0
[R2-Tunnel0/0/0]nhrp entry 192.168.6.1 10.1.1.1 register
[R2-Tunnel0/0/0]nhrp network-id 100
[R3]int t0/0/0
[R3-Tunnel0/0/0]ip address 192.168.6.3 24
[R3-Tunnel0/0/0]tunnel-protocol gre p2mp
[R3-Tunnel0/0/0]source GigabitEthernet0/0/0
[R3-Tunnel0/0/0]nhrp entry 192.168.6.1 10.1.1.1 register
[R3-Tunnel0/0/0]nhrp network-id 100
R1，R2，R3的MAP均补全
五、OSPF路由
R1，R2，R3分别开启ospf协议
[R1]ospf 1 router-id 1.1.1.1
[R1-ospf-1]area 0
[R1-ospf-1-area-0.0.0.0]network 192.168.1.1 0.0.0.0
[R1-ospf-1-area-0.0.0.0]network 192.168.6.1 0.0.0.0
[R1-ospf-1-area-0.0.0.0]network 192.168.7.1 0.0.0.0
[R2]ospf 1 router-id 2.2.2.2
[R2-ospf-1]area 0
[R2-ospf-1-area-0.0.0.0]network 192.168.2.1 0.0.0.0
[R2-ospf-1-area-0.0.0.0]network 192.168.6.2 0.0.0.0
[R3]ospf 1 router-id 3.3.3.3
[R3-ospf-1]area 0
[R3-ospf-1-area-0.0.0.0]network 192.168.3.1 0.0.0.0
[R3-ospf-1-area-0.0.0.0]network 192.168.6.3 0.0.0.0
R1，R2，R3分别修改ospf接口网络类型为broadcast
[R1]int t0/0/0
[R1-Tunnel0/0/0]ospf network-type broadcast
[R2]int t0/0/0
[R2-Tunnel0/0/0]ospf network-type broadcast
[R3]int t0/0/0
[R3-Tunnel0/0/0]ospf network-type broadcast
R2，R3放弃选举，R1作为DR
[R2]int t0/0/0
[R2-Tunnel0/0/0]ospf dr-priority 0
[R3]int t0/0/0
[R3-Tunnel0/0/0]ospf dr-priority 0
R4，R5分别开启ospf协议
[R4]ospf 1 router-id 4.4.4.4
[R4-ospf-1]area 0
[R4-ospf-1-area-0.0.0.0]network 192.168.4.1 0.0.0.0
[R4-ospf-1-area-0.0.0.0]network 192.168.7.2 0.0.0.0
[R5]ospf 1 router-id 5.5.5.5
[R5-ospf-1]area 0
[R5-ospf-1-area-0.0.0.0]network 192.168.5.1 0.0.0.0
[R5-ospf-1-area-0.0.0.0]network 192.168.7.3 0.0.0.0
R4，R5分别修改ospf接口网络类型为broadcast
[R4]int t0/0/0
[R4-Tunnel0/0/0]ospf network-type broadcast
[R5]int t0/0/0
[R5-Tunnel0/0/0]ospf network-type broadcast
各路由器OSPF协议均正常工作，建立邻接关系
