要求：
1. R4为ISP，其上只能配置IP地址；R4与其他所有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；
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
分配IP地址
172.16.0.0/16 172.16.0.0/19 ------area0 172.16.0.0/24 -------P2P骨干 172.16.0.0/30 172.16.0.4/30 172.16.0.8/30 ..... 172.16.1.0/24 -------MA骨干 172.16.1.0/29 172.16.1.8/29 172.16.1.16/29 ..... 172.16.2.0/24 172.16.3.0/24 172.16.4.0/24 ...... 172.16.32.0/19 ------area1 172.16.32.0/24 -------P2P骨干 172.16.32.0/30 172.16.32.4/30 172.16.32.8/30 ..... 172.16.33.0/24 -------MA骨干 172.16.33.0/29 172.16.33.8/29 172.16.33.16/29 ..... 172.16.34.0/24 172.16.35.0/24 172.16.36.0/24 ...... 172.16.64.0/19 ------area2 172.16.64.0/24 -------P2P骨干 172.16.64.0/30 172.16.64.4/30 172.16.64.8/30 ..... 172.16.65.0/24 -------MA骨干 172.16.65.0/29 172.16.65.8/29 172.16.65.16/29 ..... 172.16.66.0/24 172.16.67.0/24 172.16.68.0/24 ...... 172.16.96.0/19 ------area3 172.16.96.0/24 -------P2P骨干 172.16.96.0/30 172.16.96.4/30 172.16.96.8/30 ..... 172.16.97.0/24 -------MA骨干 172.16.97.0/29 172.16.97.8/29 172.16.97.16/29 ..... 172.16.98.0/24 172.16.99.0/24 172.16.100.0/24 ...... 172.16.128.0/19 ------area4 172.16.128.0/24 -------P2P骨干 172.16.128.0/30 172.16.128.4/30 172.16.128.8/30 ..... 172.16.129.0/24 -------MA骨干 172.16.129.0/29 172.16.129.8/29 172.16.129.16/29 ..... 172.16.130.0/24 172.16.131.0/24 172.16.132.0/24 ...... 172.16.160.0/19 ------rip 172.16.160.0/20 172.16.176.0/20 172.16.192.0/19 172.16.224.0/19
R1
[R1]int LoopBack 0 [R1-LoopBack0]ip add 172.16.34.1 24 [R1]int g 0/0/0 [R1-GigabitEthernet0/0/0]ip add 172.16.33.1 24
R2
[R2]int LoopBack 0 [R2-LoopBack0]ip add 172.16.35.1 24 [R2]int g 0/0/0 [R2-GigabitEthernet0/0/0]ip add 172.16.33.2 24
R3
[R3]int g 0/0/0 [R3-GigabitEthernet0/0/0]ip add 172.16.33.3 24 [R3]int LoopBack 0 [R3-LoopBack0]ip add 172.16.36.1 24 [R3]int s 4/0/0 [R3-Serial4/0/0]ip add 34.0.0.1 30
R4
[R4]int s 3/0/0 [R4-Serial3/0/0]ip add 34.0.0.2 30 [R4]int g 0/0/2 [R4-GigabitEthernet0/0/2]ip add 74.0.0.2 29 [R4]int s 4/0/0 [R4-Serial4/0/0]ip add 54.0.0.2 30 [R4]int s 3/0/1 [R4-Serial3/0/1]ip add 64.0.0.2 30 [R4]int LoopBack 0 [R4-LoopBack0]ip add 4.4.4.4 24
R5
[R5]int LoopBack 0 [R5-LoopBack0]ip add 172.16.2.1 24 [R5]int s 4/0/0 [R5-Serial4/0/0]ip add 54.0.0.1 30
R6
[R6]int s 4/0/0 [R6-Serial4/0/0]ip add 64.0.0.1 30 [R6]int LoopBack 0 [R6-LoopBack0]ip add 172.16.3.1 24 [R6]int g 0/0/1 [R6-GigabitEthernet0/0/1]ip add 172.16.65.1 29
R7
[R7]int g 0/0/0 [R7-GigabitEthernet0/0/0]ip add 74.0.0.1 29 [R7]interface LoopBack 0 [R7-LoopBack0]ip add 172.16.4.1 24 [R7]int g 0/0/1 [R7-GigabitEthernet0/0/1]ip add 172.16.97.1 29
R8
[R8]int g 0/0/0 [R8-GigabitEthernet0/0/0]ip add 172.16.97.2 29 [R8]int g 0/0/1 [R8-GigabitEthernet0/0/1]ip add 172.16.97.9 29 [R8]int LoopBack 0 [R8-LoopBack0]ip add 172.16.98.1 24
R9
[R9]int g 0/0/0 [R9-GigabitEthernet0/0/0]ip add 172.16.97.10 29 [R9]int g 0/0/1 [R9-GigabitEthernet0/0/1]ip add 172.16.129.1 29 [R9]int LoopBack 0 [R9-LoopBack0]ip add 172.16.130.1 24
R10
[R10]int g 0/0/0 [R10-GigabitEthernet0/0/0]ip add 172.16.129.2 29 [R10]int LoopBack 0 [R10-LoopBack0]ip add 172.16.131.1 24
R11
[R11]int g 0/0/0 [R11-GigabitEthernet0/0/0]ip add 172.16.65.2 29 [R11]int g 0/0/1 [R11-GigabitEthernet0/0/1]ip add 172.16.65.9 29 [R11]int LoopBack 0 [R11-LoopBack0]ip add 172.16.66.1 24
R12
[R12]int g 0/0/0 [R12-GigabitEthernet0/0/0]ip add 172.16.65.10 29 [R12]int LoopBack 0 [R12-LoopBack0]ip add 172.16.160.1 20 [R12]int LoopBack 1 [R12-LoopBack1]ip add 172.16.176.1 20
配置MGRE环境
配置之前先配置缺省路由
[R3]ip route-static 0.0.0.0 0 34.0.0.2 [R5]ip route-static 0.0.0.0 0 54.0.0.2 [R6]ip route-static 0.0.0.0 0 64.0.0.2 [R7]ip route-static 0.0.0.0 0 74.0.0.2
R3
[R3]int Tunnel 0/0/0 [R3-Tunnel0/0/0]ip add 172.16.1.1 29 [R3-Tunnel0/0/0]tunnel-protocol gre p2mp [R3-Tunnel0/0/0]source 34.0.0.1 [R3-Tunnel0/0/0]nhrp network-id 100 [R3-Tunnel0/0/0]nhrp entry multicast dynamic
R5
[R5]int Tunnel 0/0/0 [R5-Tunnel0/0/0]ip add 172.16.1.2 29 [R5-Tunnel0/0/0]tunnel-protocol gre p2mp [R5-Tunnel0/0/0]source Serial 4/0/0 [R5-Tunnel0/0/0]nhrp network-id 100 [R5-Tunnel0/0/0]nhrp entry 172.16.1.1 34.0.0.1 register
R6
[R6]int Tunnel 0/0/0 [R6-Tunnel0/0/0]ip add 172.16.1.3 29 [R6-Tunnel0/0/0]tunnel-protocol gre p2mp [R6-Tunnel0/0/0]source Serial 4/0/0 [R6-Tunnel0/0/0]nhrp network-id 100 [R6-Tunnel0/0/0]nhrp entry 172.16.1.1 34.0.0.1 register
R7
[R7]int Tunnel 0/0/0 [R7-Tunnel0/0/0]ip add 172.16.1.4 29 [R7-Tunnel0/0/0]tunnel-protocol gre p2mp [R7-Tunnel0/0/0]source GigabitEthernet 0/0/0 [R7-Tunnel0/0/0]nhrp network-id 100 [R7-Tunnel0/0/0]nhrp entry 172.16.1.1 34.0.0.1 register
测试
配置OSPF环境
R1
[R1]ospf 1 router-id 1.1.1.1 [R1-ospf-1]area 1 [R1-ospf-1-area-0.0.0.1]network 172.16.0.0 0.0.255.255
R2
[R2]ospf 1 router-id 2.2.2.2 [R2-ospf-1]area 1 [R2-ospf-1-area-0.0.0.1]network 172.16.0.0 0.0.255.255
R3
[R3]ospf 1 router-id 3.3.3.3 [R3-ospf-1]area 1 [R3-ospf-1-area-0.0.0.1]network 172.16.32.0 0.0.7.255 [R3-ospf-1-area-0.0.0.1]q [R3-ospf-1]area 0 [R3-ospf-1-area-0.0.0.0]network 172.16.1.1 0.0.0.0
R5
[R5]ospf 1 router-id 5.5.5.5 [R5-ospf-1]area 0 [R5-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255
R6
[R6]ospf 1 router-id 6.6.6.6 [R6-ospf-1]area 0 [R6-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.3.255 [R6-ospf-1-area-0.0.0.0]q [R6-ospf-1]area 2 [R6-ospf-1-area-0.0.0.2]network 172.16.65.1 0.0.0.0
R7
[R7]ospf 1 router-id 7.7.7.7 [R7-ospf-1]area 0 [R7-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.7.255 [R7-ospf-1-area-0.0.0.0]q [R7-ospf-1]area 3 [R7-ospf-1-area-0.0.0.3]network 172.16.97.1 0.0.0.0
R8
[R8]ospf 1 router-id 8.8.8.8 [R8-ospf-1]area 3 [R8-ospf-1-area-0.0.0.3]network 172.16.0.0 0.0.255.255
R9
[R9]ospf 1 router-id 9.9.9.9 [R9-ospf-1]area 3 [R9-ospf-1-area-0.0.0.3]network 172.16.97.10 0.0.0.0 [R9-ospf-1-area-0.0.0.3]q [R9-ospf-1]q [R9]ospf 2 router-id 9.9.9.9 [R9-ospf-2]area 4 [R9-ospf-2-area-0.0.0.4]network 172.16.128.0 0.0.3.255
R10
[R10]ospf 1 router-id 10.10.10.10 [R10-ospf-1]area 4 [R10-ospf-1-area-0.0.0.4]network 172.16.0.0 0.0.255.255
R11
[R11]ospf 1 router-id 11.11.11.11 [R11-ospf-1]area 2 [R11-ospf-1-area-0.0.0.2]network 172.16.0.0 0.0.255.255
R12
[R12]ospf 1 router-id 12.12.12.12 [R12-ospf-1]area 2 [R12-ospf-1-area-0.0.0.2]network 172.16.65.10 0.0.0.0 [R12]rip 1 [R12-rip-1]version 2 [R12-rip-1]network 172.16.0.0
我们创建的MGRE环境是一个P2P类型，所以他无法和其他路由器建立邻居关系，我们需要修改它的网络类型，让他和其他路由器建立邻居关系。
[R3]int Tunnel 0/0/0 [R3-Tunnel0/0/0]ospf network-type p2mp [R5]int Tunnel 0/0/0 [R5-Tunnel0/0/0]ospf network-type p2mp [R6]int Tunnel 0/0/0 [R6-Tunnel0/0/0]ospf network-type p2mp [R7]int Tunnel 0/0/0 [R7-Tunnel0/0/0]ospf network-type p2mp
查看路由表我们发现我们还缺少area4区域和rip区域的路由，这里我们使用重发布的方式导入rip路由和area4的路由信息
[R12]ospf 1 [R12-ospf-1]import-route rip 1
[R9]ospf 1 [R9-ospf-1]import-route ospf 2
为了减少LSA的更新量，我们需要做汇总与特殊区域
汇总如下（在汇总时为了避免环路我们还需要配置空接口路由）：
[R3]ospf 1 [R3-ospf-1]area 1 [R3-ospf-1-area-0.0.0.1]abr-summary 172.16.32.0 255.255.224.0 [R3]ip route-static 172.16.32.0 19 NULL 0
[R6]ospf 1 [R6-ospf-1]area 2 [R6-ospf-1-area-0.0.0.2]abr-summary 172.16.64.0 255.255.224.0 [R6]ip route-static 172.16.64.0 19 NULL 0
[R7]ospf 1 [R7-ospf-1]area 3 [R7-ospf-1-area-0.0.0.3]abr-summary 172.16.96.0 255.255.224.0 [R7]ip route-static 172.16.96.0 19 NULL 0
[R9]ospf 1 [R9-ospf-1]asbr-summary 172.16.128.0 255.255.224.0 [R9]ip route-static 172.16.128.0 19 NULL 0
[R12]ospf 1 [R12-ospf-1]asbr-summary 172.16.160.0 255.255.224.0 [R12]ip route-static 172.16.160.0 19 NULL 0
这里为什么会多出来一条172.16.65.8这条网段的路由呢？是因为我们宣告RIP时是按照主类进行宣告的，所以它也包含了这条路由信息
配置特殊区域：
[R1]ospf 1 [R1-ospf-1]area 1 [R1-ospf-1-area-0.0.0.1]stub
[R2]ospf 1 [R2-ospf-1]area 1 [R2-ospf-1-area-0.0.0.1]stub
[R3]ospf 1 [R3-ospf-1]area 1 [R3-ospf-1-area-0.0.0.1]stub no-summary
[R7]ospf 1 [R7-ospf-1]area 3 [R7-ospf-1-area-0.0.0.3]nssa no-summary
[R8]ospf 1 [R8-ospf-1]area 3 [R8-ospf-1-area-0.0.0.3]nssa
[R9]ospf 1 [R9-ospf-1]area 3 [R9-ospf-1-area-0.0.0.3]nssa
[R6]ospf 1 [R6-ospf-1]area 2 [R6-ospf-1-area-0.0.0.2]nssa no-summary
[R11]ospf 1 [R11-ospf-1]area 2 [R11-ospf-1-area-0.0.0.2]nssa
[R12]ospf 1 [R12-ospf-1]area 2 [R12-ospf-1-area-0.0.0.2]nssa
可以看到我们的R10里面没有其他的路由信息，这时我们可以下发一条缺省路由指向我们的R9
[R9]ospf 2 [R9-ospf-2]default-route-advertise
配置NAT环境,完成所有设备均可访问R4的环回
[R3]acl 2000 [R3-acl-basic-2000]rule permit source 172.16.0.0 0.0.255.255 [R3-acl-basic-2000]q [R3]int Serial 4/0/0 [R3-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-acl-basic-2000]q [R7]int g 0/0/0 [R7-GigabitEthernet0/0/0]nat outbound 2000
[R6]acl 2000 [R6-acl-basic-2000]rule permit source 172.16.0.0 0.0.255.255 [R6-acl-basic-2000]q [R6]int s 4/0/0 [R6-Serial4/0/0]nat outbound 2000
加快收敛
减少计时器时间
更改了hello时间区域内的其他路由器也必须改为相同的，要不然建立不了邻居关系
[R5]int t 0/0/0 [R5-Tunnel0/0/0]ospf timer hello 5
[R3]int t 0/0/0 [R3-Tunnel0/0/0]ospf timer hello 5
[R6]int t 0/0/0 [R6-Tunnel0/0/0]ospf timer hello 5
[R7]int t 0/0/0 [R7-Tunnel0/0/0]ospf timer hello 5
更改了hello时间死亡时间也会自动改变
保障更新安全
进行手工认证，我这里采用区域认证（实际上也是接口认证）
[R2]ospf 1 [R2-ospf-1]area 1 [R2-ospf-1-area-0.0.0.1]authentication-mode md5 1 cipher 123456
[R1]ospf 1 [R1-ospf-1]area 1 [R1-ospf-1-area-0.0.0.1]authentication-mode md5 1 123456
[R3]ospf 1 [R3-ospf-1]area 1 [R3-ospf-1-area-0.0.0.1]authentication-mode md5 1 cipher 123456
测试全网可达
