一，R6为ISP只能配置IP地址，R1-R5的环回为私有网段
1.首先给各个设备分配IP并设置缺省使全网可达
2.配置完成后ping一下其他路由器发现都通
二，R1/2/3为星型的拓扑结构（MGRE），R1为中心站点
[r1]int Tunnel 0/0/0
[r1-Tunnel0/0/0]ip add 192.168.7.1 24
[r1-Tunnel0/0/0]tunnel-protocol gre p2mp
[r1-Tunnel0/0/0]source 16.0.0.1
Sep 18 2022 18:43:45-08:00 r1 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP
on the interface Tunnel0/0/0 has entered the UP state.
[r1-Tunnel0/0/0]nhrp network-id 100R2配置
[r1]int Tunnel 0/0/0
[r1-Tunnel0/0/0]ip add 192.168.7.1 24
[r1-Tunnel0/0/0]tunnel-protocol gre p2mp
[r1-Tunnel0/0/0]source 16.0.0.1
Sep 18 2022 18:43:45-08:00 r1 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP
on the interface Tunnel0/0/0 has entered the UP state.
[r1-Tunnel0/0/0]nhrp network-id 100R3配置
[r3]int t0/0/0
[r3-Tunnel0/0/0]ip add 192.168.7.3 24
[r3-Tunnel0/0/0]tunnel-protocol gre p2mp
[r3-Tunnel0/0/0]source GigabitEthernet 0/0/0
Sep 18 2022 18:46:16-08:00 r3 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP
on the interface Tunnel0/0/0 has entered the UP state.
[r3-Tunnel0/0/0]nhrp network-id 100
[r3-Tunnel0/0/0]nhrp entry 192.168.7.1 16.0.0.1 register 在R1中心站点上查询到R2，R3上交的表
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三，R1/4/5为全连的MGRE结构
R1为中心
R1配置
[r1]int t0/0/1
[r1-Tunnel0/0/1]ip add 192.168.8.1 24
[r1-Tunnel0/0/1]tunnel-protocol gre p2mp
[r1-Tunnel0/0/1]source 61.0.0.1
Sep 18 2022 19:00:23-08:00 r1 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP
on the interface Tunnel0/0/1 has entered the UP state.
[r1-Tunnel0/0/1]nhrp network-id 200R4配置
[r4]int t0/0/1
[r4-Tunnel0/0/1]ip add 192.168.8.2 24
[r4-Tunnel0/0/1]tunnel-protocol gre p2mp
[r4-Tunnel0/0/1]source g0/0/0
Sep 18 2022 19:02:34-08:00 r4 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP
on the interface Tunnel0/0/1 has entered the UP state.
[r4-Tunnel0/0/1]nhrp network-id 200
[r4-Tunnel0/0/1]nhrp entry 192.168.8.1 61.0.0.1 registerR5配置
[r5]int t0/0/1
[r5-Tunnel0/0/1]ip add 192.168.8.3 24
[r5-Tunnel0/0/1]tunnel-protocol gre p2mp
[r5-Tunnel0/0/1]source g0/0/0
Sep 18 2022 19:03:48-08:00 r5 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP
on the interface Tunnel0/0/1 has entered the UP state.
[r5-Tunnel0/0/1]nhrp network-id 200
[r5-Tunnel0/0/1]nhrp entry 192.168.8.1 61.0.0.1 registerR4为中心
R4配置
[r4-Tunnel0/0/1]source 46.0.0.1
[r4-Tunnel0/0/1]nhrp network-id 400R1配置
[r1-Tunnel0/0/1]source g0/0/0
[r1-Tunnel0/0/1]nhrp network-id 400
[r1-Tunnel0/0/1]nhrp entry 192.168.8.2 46.0.0.1 registerR5配置
[r5-Tunnel0/0/1]source g0/0/0
[r5-Tunnel0/0/1]nhrp network-id 400
[r5-Tunnel0/0/1]nhrp entry 192.168.8.2 46.0.0.1 registerR5为中心
R5配置
[r5-Tunnel0/0/1]source 56.0.0.1
[r5-Tunnel0/0/1]nhrp network-id 500R1配置
[r1-Tunnel0/0/1]nhrp network-id 500
[r1-Tunnel0/0/1]nhrp entry 192.168.8.3 56.0.0.1 registerR4配置
[r4-Tunnel0/0/1]nhrp network-id 500
[r4-Tunnel0/0/1]nhrp entry 192.168.8.3 56.0.0.1 register四，所有私有网段可以互相通讯，使用OSPF完成
由于MGRE环境不支持组播，所以需要开启伪广播
[r1-Tunnel0/0/0]nhrp entry multicast dynamic
在R1-5上开启OSPF
由于通道p2p为点到点所以改为 broadcast
ospf network-type broadcast
#需进入每个接口修改最后查路由表可以看到都在
[r1]display ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 27 Routes : 28
Destination/Mask Proto Pre Cost Flags NextHop Interface
0.0.0.0/0 Static 60 0 RD 61.0.0.2 GigabitEthernet
0/0/0
Static 60 0 RD 16.0.0.2 GigabitEthernet
0/0/1
16.0.0.0/24 Direct 0 0 D 16.0.0.1 GigabitEthernet
0/0/1
16.0.0.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
16.0.0.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
61.0.0.0/24 Direct 0 0 D 61.0.0.1 GigabitEthernet
0/0/0
61.0.0.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
61.0.0.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
192.168.1.0/24 Direct 0 0 D 192.168.1.1 LoopBack0
192.168.1.1/32 Direct 0 0 D 127.0.0.1 LoopBack0
192.168.1.255/32 Direct 0 0 D 127.0.0.1 LoopBack0
192.168.2.1/32 OSPF 10 1562 D 192.168.7.2 Tunnel0/0/0
192.168.3.1/32 OSPF 10 1562 D 192.168.7.3 Tunnel0/0/0
192.168.4.1/32 OSPF 10 1562 D 192.168.8.2 Tunnel0/0/1
192.168.5.1/32 OSPF 10 1562 D 192.168.8.3 Tunnel0/0/1
192.168.6.0/24 Direct 0 0 D 192.168.6.1 LoopBack1
192.168.6.1/32 Direct 0 0 D 127.0.0.1 LoopBack1
192.168.6.255/32 Direct 0 0 D 127.0.0.1 LoopBack1
192.168.7.0/24 Direct 0 0 D 192.168.7.1 Tunnel0/0/0
192.168.7.1/32 Direct 0 0 D 127.0.0.1 Tunnel0/0/0
192.168.7.255/32 Direct 0 0 D 127.0.0.1 Tunnel0/0/0
192.168.8.0/24 Direct 0 0 D 192.168.8.1 Tunnel0/0/1
192.168.8.1/32 Direct 0 0 D 127.0.0.1 Tunnel0/0/1
192.168.8.255/32 Direct 0 0 D 127.0.0.1 Tunnel0/0/1
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0所有私有网段互相通信
