OSPF+MGRE

步骤：
1.根据图中网段，给路由器配置IP地址和环回






2.将公有网段做通，在边界路由器上写缺省
[R1]ip route-static 0.0.0.0 0 16.1.1.2
[R1]ip route-static 0.0.0.0 0 61.1.1.2
[R2]ip route-static 0.0.0.0 0 26.1.1.1
[R3]ip route-static 0.0.0.0 0 36.1.1.2
[R4]ip route-static 0.0.0.0 0 46.1.1.2
[R5]ip route-static 0.0.0.0 0 56.1.1.2

3.R1、R4、R5为全连的MGRE结构



4.R1、R2、R3为星型拓扑结构，R1为中心站点



5.做通私网----------启ospf协议





6.由于MGRE默认为点到点的工作方式，该方式只能建立一个邻居，故在NBMA环境下将无法和所有节点建立关系，因此需要修改接口的工作方式
[R1]int Tunnel 0/0/0
[R1-Tunnel0/0/0]ospf network-type broadcast
[R1]int Tunnel 0/0/1
[R1-Tunnel0/0/1]ospf network-type broadcast

[R2]int Tunnel 0/0/1
[R2-Tunnel0/0/1]ospf network-type broadcast

[R3]int Tunnel 0/0/1
[R3-Tunnel0/0/1]ospf network-type broadcast

[R4]int Tunnel 0/0/0
[R4-Tunnel0/0/0]ospf network-type broadcast

[R5]int Tunnel 0/0/0
[R5-Tunnel0/0/0]ospf network-type broadcast

7.将R2，R3tunnel口的优先级改为0，使它们不参选

此时R1不是DR，将R2，R3tunnel口的优先级改为0，使它们不参选

[R2]int t0/0/1
[R2-Tunnel0/0/1]ospf d
[R2-Tunnel0/0/1]ospf dr-priority 0

[R3]int t0/0/1
[R3-Tunnel0/0/1]ospf d
[R3-Tunnel0/0/1]ospf dr-priority 0

8.测试