实验4 OSPF的特殊区域STUB和NSSA

实验任务一：STUB区域配置

  1. 建立物理连接

  2. RTA,RTB,RTC,RTD配置ospf
    [RTA-ospf-1-area-0.0.0.1]network 10.0.0.0 0.0.0.255
    [RTA-ospf-1-area-0.0.0.1]network 1.1.1.1 0.0.0.0

[RTB-ospf-1-area-0.0.0.1]network 10.0.0.0 0.0.0.255
[RTB-ospf-1-area-0.0.0.0]network 2.2.2.2 0.0.0.0
[RTB-ospf-1-area-0.0.0.0]network 20.0.0.0 0.0.0.255

[RTC-ospf-1-area-0.0.0.2]network 30.0.0.0 0.0.0.255
[RTC-ospf-1-area-0.0.0.0]network 3.3.3.3 0.0.0.0
[RTC-ospf-1-area-0.0.0.0]network 20.0.0.0 0.0.0.255

[RTD-ospf-1-area-0.0.0.2]network 30.0.0.0 0.0.0.255
[RTD-ospf-1-area-0.0.0.2]network 4.4.4.4 0.0.0.0

查看RTD的路由表
[RTD]display ip routing-table

Destinations : 22 Routes : 22

Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
1.1.1.1/32 O_INTER 10 3 30.0.0.1 GE0/2
2.2.2.2/32 O_INTER 10 2 30.0.0.1 GE0/2
3.3.3.3/32 O_INTER 10 1 30.0.0.1 GE0/2
4.4.4.4/32 Direct 0 0 127.0.0.1 InLoop0
10.0.0.0/24 O_INTER 10 3 30.0.0.1 GE0/2
20.0.0.0/24 O_INTER 10 2 30.0.0.1 GE0/2
30.0.0.0/24 Direct 0 0 30.0.0.2 GE0/2
30.0.0.0/32 Direct 0 0 30.0.0.2 GE0/2
30.0.0.2/32 Direct 0 0 127.0.0.1 InLoop0
30.0.0.255/32 Direct 0 0 30.0.0.2 GE0/2
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
192.168.0.0/24 O_ASE2 150 1 30.0.0.1 GE0/2
192.168.1.0/24 O_ASE2 150 1 30.0.0.1 GE0/2
192.168.2.0/24 O_ASE2 150 1 30.0.0.1 GE0/2
192.168.3.0/24 O_ASE2 150 1 30.0.0.1 GE0/2
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
3.Area设置为stub区域
[RTC-ospf-1-area-0.0.0.2]stub
[RTD-ospf-1-area-0.0.0.2]stub

[RTD]display ip routing-table

Destinations : 19 Routes : 19

Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/0 O_INTER 10 2 30.0.0.1 GE0/2
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
1.1.1.1/32 O_INTER 10 3 30.0.0.1 GE0/2
2.2.2.2/32 O_INTER 10 2 30.0.0.1 GE0/2
3.3.3.3/32 O_INTER 10 1 30.0.0.1 GE0/2
4.4.4.4/32 Direct 0 0 127.0.0.1 InLoop0
10.0.0.0/24 O_INTER 10 3 30.0.0.1 GE0/2
20.0.0.0/24 O_INTER 10 2 30.0.0.1 GE0/2
30.0.0.0/24 Direct 0 0 30.0.0.2 GE0/2
30.0.0.0/32 Direct 0 0 30.0.0.2 GE0/2
30.0.0.2/32 Direct 0 0 127.0.0.1 InLoop0
30.0.0.255/32 Direct 0 0 30.0.0.2 GE0/2
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

设置了STUB区域后，外部路由没有了，只有一个自动下发的三类LSA默认路由。

实验任务二：配置totally stub区域

  1. Area2设置为totally stub
    [RTC-ospf-1-area-0.0.0.2]stub no-summary
    [RTD-ospf-1-area-0.0.0.2]stub no-summary
    2.查看RTD路由
    [RTD]display ip routing

Destinations : 14 Routes : 14

Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/0 O_INTER 10 2 30.0.0.1 GE0/2
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
4.4.4.4/32 Direct 0 0 127.0.0.1 InLoop0
30.0.0.0/24 Direct 0 0 30.0.0.2 GE0/2
30.0.0.0/32 Direct 0 0 30.0.0.2 GE0/2
30.0.0.2/32 Direct 0 0 127.0.0.1 InLoop0
30.0.0.255/32 Direct 0 0 30.0.0.2 GE0/2
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

[RTD]display ospf lsdb

     OSPF Process 1 with Router ID 4.4.4.4
             Link State Database

                     Area: 0.0.0.2

Type LinkState ID AdvRouter Age Len Sequence Metric
Router 3.3.3.3 3.3.3.3 300 36 80000004 0
Router 4.4.4.4 4.4.4.4 299 48 80000004 0
Network 30.0.0.2 4.4.4.4 299 32 80000002 0
Sum-Net 0.0.0.0 3.3.3.3 351 28 80000001 1
没有三类LSA的明细路由，自动下发一个三类LSA的默认路由

实验任务三：配置nssa区域
（1）不在NSSA区域引入外部路由
1.在实验任务二的基础是，直接配置nssa
[RTC-ospf-1-area-0.0.0.2]nssa
OSPF Area is already configured as a stub area.
发现不能在stub区域的基础上配置nssa,只能转为普通区域之后再配置nssa
[RTD]display ip routing-table

Destinations : 18 Routes : 18

Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
1.1.1.1/32 O_INTER 10 3 30.0.0.1 GE0/2
2.2.2.2/32 O_INTER 10 2 30.0.0.1 GE0/2
3.3.3.3/32 O_INTER 10 1 30.0.0.1 GE0/2
4.4.4.4/32 Direct 0 0 127.0.0.1 InLoop0
10.0.0.0/24 O_INTER 10 3 30.0.0.1 GE0/2
20.0.0.0/24 O_INTER 10 2 30.0.0.1 GE0/2
30.0.0.0/24 Direct 0 0 30.0.0.2 GE0/2
30.0.0.0/32 Direct 0 0 30.0.0.2 GE0/2
30.0.0.2/32 Direct 0 0 127.0.0.1 InLoop0
30.0.0.255/32 Direct 0 0 30.0.0.2 GE0/2
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

和stub和totally stub不同，没有三类LSA的默认路由下发，但是没有外部路由。
需要手动下发七类LSA的默认路由
[RTC-ospf-1-area-0.0.0.2]nssa default-route-advertise
[RTD-ospf-1-area-0.0.0.2]display ip routing-table

Destinations : 19 Routes : 19

Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/0 O_NSSA2 150 1 30.0.0.1 GE0/2
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
1.1.1.1/32 O_INTER 10 3 30.0.0.1 GE0/2
2.2.2.2/32 O_INTER 10 2 30.0.0.1 GE0/2
3.3.3.3/32 O_INTER 10 1 30.0.0.1 GE0/2
4.4.4.4/32 Direct 0 0 127.0.0.1 InLoop0
10.0.0.0/24 O_INTER 10 3 30.0.0.1 GE0/2
20.0.0.0/24 O_INTER 10 2 30.0.0.1 GE0/2
30.0.0.0/24 Direct 0 0 30.0.0.2 GE0/2
30.0.0.0/32 Direct 0 0 30.0.0.2 GE0/2
30.0.0.2/32 Direct 0 0 127.0.0.1 InLoop0
30.0.0.255/32 Direct 0 0 30.0.0.2 GE0/2
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

（1）在NSSA区域引入外部路由
1.在area配置NSSA区域
[RTA-ospf-1-area-0.0.0.1]nssa
[RTB-ospf-1-area-0.0.0.1]nssa

[RTA]display ospf lsdb

     OSPF Process 1 with Router ID 1.1.1.1
             Link State Database

                     Area: 0.0.0.1

Type LinkState ID AdvRouter Age Len Sequence Metric
Router 1.1.1.1 1.1.1.1 264 48 80000004 0
Router 2.2.2.2 2.2.2.2 265 36 80000004 0
Network 10.0.0.2 2.2.2.2 265 32 80000001 0
Sum-Net 20.0.0.0 2.2.2.2 317 28 80000001 1
Sum-Net 3.3.3.3 2.2.2.2 317 28 80000001 1
Sum-Net 4.4.4.4 2.2.2.2 305 28 80000001 2
Sum-Net 2.2.2.2 2.2.2.2 317 28 80000001 0
Sum-Net 30.0.0.0 2.2.2.2 317 28 80000001 2
NSSA 10.0.0.0 1.1.1.1 307 36 80000001 1
NSSA 192.168.2.0 1.1.1.1 306 36 80000001 1
NSSA 192.168.3.0 1.1.1.1 306 36 80000001 1
NSSA 192.168.0.0 1.1.1.1 306 36 80000001 1
NSSA 192.168.1.0 1.1.1.1 306 36 80000001 1
NSSA 1.1.1.1 1.1.1.1 307 36 80000001 1
NSSA引入外部路由，以七类LSA形式传递路由。
[RTB]display ospf lsdb

     OSPF Process 1 with Router ID 2.2.2.2
             Link State Database

                     Area: 0.0.0.0

Type LinkState ID AdvRouter Age Len Sequence Metric
Router 3.3.3.3 3.3.3.3 378 48 80000009 0
Router 2.2.2.2 2.2.2.2 337 48 80000009 0
Network 20.0.0.2 3.3.3.3 410 32 80000004 0
Sum-Net 4.4.4.4 3.3.3.3 326 28 80000001 1
Sum-Net 10.0.0.0 2.2.2.2 492 28 80000003 1
Sum-Net 1.1.1.1 2.2.2.2 285 28 80000001 1
Sum-Net 30.0.0.0 3.3.3.3 426 28 80000003 1

                     Area: 0.0.0.1

Type LinkState ID AdvRouter Age Len Sequence Metric
Router 1.1.1.1 1.1.1.1 286 48 80000004 0
Router 2.2.2.2 2.2.2.2 285 36 80000004 0
Network 10.0.0.2 2.2.2.2 285 32 80000001 0
Sum-Net 20.0.0.0 2.2.2.2 337 28 80000001 1
Sum-Net 3.3.3.3 2.2.2.2 337 28 80000001 1
Sum-Net 4.4.4.4 2.2.2.2 325 28 80000001 2
Sum-Net 2.2.2.2 2.2.2.2 337 28 80000001 0
Sum-Net 30.0.0.0 2.2.2.2 337 28 80000001 2
NSSA 10.0.0.0 1.1.1.1 329 36 80000001 1
NSSA 192.168.2.0 1.1.1.1 328 36 80000001 1
NSSA 192.168.3.0 1.1.1.1 328 36 80000001 1
NSSA 192.168.0.0 1.1.1.1 328 36 80000001 1
NSSA 192.168.1.0 1.1.1.1 328 36 80000001 1
NSSA 1.1.1.1 1.1.1.1 329 36 80000001 1

             AS External Database

Type LinkState ID AdvRouter Age Len Sequence Metric
External 192.168.2.0 2.2.2.2 285 36 80000001 1
External 192.168.3.0 2.2.2.2 285 36 80000001 1
External 192.168.0.0 2.2.2.2 285 36 80000001 1
External 192.168.1.0 2.2.2.2 285 36 80000001 1
External 10.0.0.0 1.1.1.1 1264 36 80000002 1
External 192.168.2.0 1.1.1.1 1264 36 80000002 1
External 192.168.3.0 1.1.1.1 1264 36 80000002 1
External 192.168.0.0 1.1.1.1 1264 36 80000002 1
External 192.168.1.0 1.1.1.1 1264 36 80000002 1
External 1.1.1.1 1.1.1.1 1264 36 80000002 1

为什么10.0.0.0和1.1.1.1只有一条，而其他的有两条？
NSSA区域RTA引入外部路由，以七类LSA注入lsdb。RTB把七类LSA传送给骨干区域，把RTA七类LSA转换为五类LSA的，RTB作为NSSA引入外部路由的ASBR，继续把五类LSA传递下去。因为10.0.0.0 、1.1.1.1在NSSA已经以三类LSA传递给骨干区域了，不再以七类转五类继续传递给其他区域，即是，NSSA传递七类LSA，只把最优LSA传递给邻居区域。

[RTC]display ospf lsdb

     OSPF Process 1 with Router ID 3.3.3.3
             Link State Database

                     Area: 0.0.0.0

Type LinkState ID AdvRouter Age Len Sequence Metric
Router 3.3.3.3 3.3.3.3 643 48 80000009 0
Router 2.2.2.2 2.2.2.2 604 48 80000009 0
Network 20.0.0.2 3.3.3.3 675 32 80000004 0
Sum-Net 4.4.4.4 3.3.3.3 591 28 80000001 1
Sum-Net 10.0.0.0 2.2.2.2 759 28 80000003 1
Sum-Net 1.1.1.1 2.2.2.2 552 28 80000001 1
Sum-Net 30.0.0.0 3.3.3.3 691 28 80000003 1

                     Area: 0.0.0.2

Type LinkState ID AdvRouter Age Len Sequence Metric
Router 3.3.3.3 3.3.3.3 591 36 80000005 0
Router 4.4.4.4 4.4.4.4 592 48 80000004 0
Network 30.0.0.2 4.4.4.4 591 32 80000002 0
Sum-Net 20.0.0.0 3.3.3.3 643 28 80000001 1
Sum-Net 3.3.3.3 3.3.3.3 643 28 80000001 0
Sum-Net 2.2.2.2 3.3.3.3 643 28 80000001 1
Sum-Net 10.0.0.0 3.3.3.3 643 28 80000001 2
Sum-Net 1.1.1.1 3.3.3.3 551 28 80000001 2
Sum-Asbr 2.2.2.2 3.3.3.3 603 28 80000001 1

             AS External Database

Type LinkState ID AdvRouter Age Len Sequence Metric
External 10.0.0.0 1.1.1.1 1531 36 80000002 1
External 192.168.2.0 2.2.2.2 552 36 80000001 1
External 192.168.2.0 1.1.1.1 1531 36 80000002 1
External 192.168.3.0 2.2.2.2 552 36 80000001 1
External 192.168.3.0 1.1.1.1 1531 36 80000002 1
External 192.168.0.0 2.2.2.2 552 36 80000001 1
External 192.168.0.0 1.1.1.1 1531 36 80000002 1
External 192.168.1.0 2.2.2.2 552 36 80000001 1
External 192.168.1.0 1.1.1.1 1531 36 80000002 1
External 1.1.1.1 1.1.1.1 1531 36 80000002 1

从上面的LSDB可以看出，RTA只有NSSA七类LSA，但是RTB area0的lsdb库没有七类LSA，只有五类LSA，七类的LSA在ABR转换为五类LSA传递给其他区域。在RTC的area2,产生了一个四类LSA通告ASBR的位置。
实验任务四：配置nssa totally区域

  1. 在RTC上配置命令
    [RTC-ospf-1-area-0.0.0.2]nssa no-summary
    2.查看RTD的路由表
    [RTD]display ip routing-table

Destinations : 14 Routes : 14

Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/0 O_INTER 10 2 30.0.0.1 GE0/2
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
4.4.4.4/32 Direct 0 0 127.0.0.1 InLoop0
30.0.0.0/24 Direct 0 0 30.0.0.2 GE0/2
30.0.0.0/32 Direct 0 0 30.0.0.2 GE0/2
30.0.0.2/32 Direct 0 0 127.0.0.1 InLoop0
30.0.0.255/32 Direct 0 0 30.0.0.2 GE0/2
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

[RTD]display ospf lsdb

     OSPF Process 1 with Router ID 4.4.4.4
             Link State Database

                     Area: 0.0.0.2

Type LinkState ID AdvRouter Age Len Sequence Metric
Router 3.3.3.3 3.3.3.3 167 36 80000006 0
Router 4.4.4.4 4.4.4.4 166 48 80000007 0
Network 30.0.0.2 4.4.4.4 155 32 80000002 0
Sum-Net 0.0.0.0 3.3.3.3 170 28 80000001 1
NSSA 0.0.0.0 3.3.3.3 662 36 80000001 1
不允许三类LSA通过NSSA区域，但是自动下发三类的默认路由。
TYPE为NSSA的需要abr配置nssa default-route-advertise产生。
TYPE为Sum-Net的是totally nssa 自动下发的三类LSA的默认路由。

【推广】 免费学中医，健康全家人
原文地址：https://www.cnblogs.com/akiz/p/11148032.html