配置缺省路由：

[R1]ip route-static 0.0.0.0 0 16.0.0.2
[R1]ip route-static 0.0.0.0 0 116.0.0.2
[R2]ip route-static 0.0.0.0 0 26.0.0.2
[R3]ip route-static 0.0.0.0 0 36.0.0.2
[R4]ip route-static 0.0.0.0 0 46.0.0.2
[R5]ip route-static 0.0.0.0 0 56.0.0.2
 

 第二步：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
R1/4/5为全连的MGRE结构

[R1]int t0/0/1
[R1-Tunnel0/0/1]ip add 11.0.0.1 24    
[R1-Tunnel0/0/1]tunnel-protocol gre p2mp 
[R1-Tunnel0/0/1]source 116.0.0.1
[R1-Tunnel0/0/1]
[R1-Tunnel0/0/1]nhrp network-id 110
[R1-Tunnel0/0/1]nhrp entry multicast dynamic 
[R1-Tunnel0/0/1]nhrp entry 11.0.0.2 46.0.0.1 register 
[R1-Tunnel0/0/1]nhrp entry 11.0.0.3 56.0.0.1 register

[R4]int t0/0/1
[R4-Tunnel0/0/1]ip add 11.0.0.2 24
[R4-Tunnel0/0/1]tunnel-protocol gre p2mp 
[R4-Tunnel0/0/1]source 46.0.0.1
[R4-Tunnel0/0/1]nhrp network-id 110
[R4-Tunnel0/0/1]nhrp entry multicast dynamic 
[R4-Tunnel0/0/1]nhrp entry 11.0.0.1 116.0.0.1 register 
[R4-Tunnel0/0/1]nhrp entry 11.0.0.3 56.0.0.1 register

[R5]int t0/0/1
[R5-Tunnel0/0/1]ip add 11.0.0.3 24
[R5-Tunnel0/0/1]tunnel-protocol gre p2mp 
[R5-Tunnel0/0/1]source 56.0.0.1
[R5-Tunnel0/0/1]nhrp network-id 110
[R5-Tunnel0/0/1]nhrp entry multicast dynamic 
[R5-Tunnel0/0/1]nhrp entry 11.0.0.1 116.0.0.1 register  
[R5-Tunnel0/0/1]nhrp entry 11.0.0.2 46.0.0.1 register
R1/2/3为星型的拓扑结构，R1为中心站点

[R2]int t 0/0/0
[R2-Tunnel0/0/0]ip add 10.0.0.2 24    
[R2-Tunnel0/0/0]tunnel-protocol gre p2mp 
[R2-Tunnel0/0/0]source GigabitEthernet 0/0/0
[R2-Tunnel0/0/0]nhrp network-id 100    
[R2-Tunnel0/0/0]nhrp entry 10.0.0.1 16.0.0.1 register 

[R3]int t 0/0/0
[R3-Tunnel0/0/0]ip add 10.0.0.3 24    
[R3-Tunnel0/0/0]tunnel-protocol gre p2mp 
[R3-Tunnel0/0/0]source GigabitEthernet 0/0/0
[R3-Tunnel0/0/0]nhrp network-id 100    
[R3-Tunnel0/0/0]nhrp entry 10.0.0.1 16.0.0.1 register 

第三步.所有私有网段可以互相通讯，私有网段使用OSPF完成

[R1]ospf 1 router-id 1.1.1.1
[R1-ospf-1-area-0.0.0.0]network 192.168.1.0 0.0.0.255    
[R1-ospf-1-area-0.0.0.0]network 10.0.0.0 0.0.0.255    
[R1-ospf-1-area-0.0.0.0]network 11.0.0.0 0.0.0.255
[R1]int t0/0/0
[R1-Tunnel0/0/0]ospf network-type p2mp
[R1]int t0/0/1
[R1-Tunnel0/0/1]ospf network-type broadcast 

[R2]ospf 1 router-id 2.2.2.2
[R2-ospf-1]area 0    
[R2-ospf-1-area-0.0.0.0]network 10.0.0.0 0.0.0.255
[R2-ospf-1-area-0.0.0.0]network 192.168.2.0 0.0.0.255
[R2]int t0/0/0
[R2-Tunnel0/0/0]ospf network-type p2mp

[R3]ospf 1 router-id 3.3.3.3
[R3-ospf-1]area 0
[R3-ospf-1-area-0.0.0.0]network 10.0.0.0 0.0.0.255
[R3-ospf-1-area-0.0.0.0]network 192.168.3.0 0.0.0.255
[R3]int t0/0/0
[R3-Tunnel0/0/0]ospf network-type p2mp
[R4]ospf 1 router-id 4.4.4.4
[R4-ospf-1]area 0
[R4-ospf-1-area-0.0.0.0]network 11.0.0.0 0.0.0.255
[R4-ospf-1-area-0.0.0.0]network 192.168.4.0 0.0.0.255
[R4]int t0/0/1
[R4-Tunnel0/0/1]ospf network-type broadcast 

[R5]ospf 1 router-id 5.5.5.5
[R5-ospf-1]area 0
[R5-ospf-1-area-0.0.0.0]network 11.0.0.0 0.0.0.255
[R5-ospf-1-area-0.0.0.0]network 192.168.5.0 0.0.0.255
[R5]int t0/0/1
[R5-Tunnel0/0/1]ospf network-type broadcast