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filter-policy
实验:
R2:ip ip-prefix rip index 10 permit 1.1.0.0 24ip ip-prefix rip index 20 permit 1.1.1.0 24ip ip-prefix rip index 30 permit 1.1.2.0 24ospf 110 router-id 2.2.2.2 filter-policy ip-prefix rip export import-route rip 1
Routing Tables: Public
Destinations : 32 Routes : 32Destination/Mask Proto Pre Cost Flags NextHop Interface
1.1.0.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0
1.1.1.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/01.1.2.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/01.1.3.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0Public routing table : OSPF
Destinations : 8 Routes : 8OSPF routing table status : <Active>
Destinations : 8 Routes : 8Destination/Mask Proto Pre Cost Flags NextHop Interface
1.1.0.0/24 O_ASE 150 1 D 23.1.1.2 GigabitEthernet0/0/1 1.1.1.0/24 O_ASE 150 1 D 23.1.1.2 GigabitEthernet0/0/1 1.1.2.0/24 O_ASE 150 1 D 23.1.1.2 GigabitEthernet0/0/1
结论:在OSPF中使用filter-policy export的作用,用于ASBR上,来过滤外部路由,不影响ASBR本身(ASBR学习到该路由不是通过OSPF,而是RIP),但影响下游路由器。 在ASBR R2上查看LSDB,已经没有了1.1.3.0这条外部LSA,自然也不会通告到R3上。所以R3以及下游路由器并不能学习到这条路由。
二、 如同上题,不过我们将filter-policy ip-prefix rip export中的export改成import,观察结果。
<R2>display ospf lsdbOSPF Process 110 with Router ID 2.2.2.2 Link State Database AS External Database
Type LinkState ID AdvRouter Age Len Sequence Metric
External 12.1.1.0 2.2.2.2 32 36 80000001 1External 1.1.2.0 2.2.2.2 690 36 80000001 1External 1.1.3.0 2.2.2.2 32 36 80000001 1External 1.1.0.0 2.2.2.2 690 36 80000001 1External 1.1.1.0 2.2.2.2 690 36 80000001 1Routing Tables: Public
Destinations : 26 Routes : 26Destination/Mask Proto Pre Cost Flags NextHop Interface
1.1.0.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0
1.1.1.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/01.1.2.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/01.1.3.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0同理,R3上也会看到1.1.3.0的外部LSA以及路由。
结论:在OSPF进程下使用filter-policy import,并不能过滤掉5类LSA。既不影响自己,也不影响下游路由器。
三、去除上述配置,在R4上使用filter-policy过滤3.3.3.0和2.2.3.0
Routing Tables: Public
Destinations : 16 Routes : 16Destination/Mask Proto Pre Cost Flags NextHop Interface
2.2.0.0/24 OSPF 10 2 D 34.1.1.3 GigabitEthernet0/0/0 2.2.1.0/24 OSPF 10 2 D 34.1.1.3 GigabitEthernet0/0/0 2.2.2.0/24 OSPF 10 2 D 34.1.1.3 GigabitEthernet0/0/0 3.3.0.0/24 OSPF 10 1 D 34.1.1.3 GigabitEthernet0/0/0 3.3.1.0/24 OSPF 10 1 D 34.1.1.3 GigabitEthernet0/0/0 3.3.2.0/24 OSPF 10 1 D 34.1.1.3 GigabitEthernet0/0/0
<R4>display ospf lsdb router 3.3.3.3
OSPF Process 110 with Router ID 4.4.4.4 Area: 0.0.0.0 Link State Database
Type : Router
Ls id : 3.3.3.3Adv rtr : 3.3.3.3 Ls age : 1230 Len : 84 Options : ABR E seq# : 80000015 chksum : 0xe197Link count: 5<R4>display ospf lsdb
OSPF Process 110 with Router ID 4.4.4.4 Link State Database Area: 0.0.0.0
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 4.4.4.4 4.4.4.4 1678 48 80000009 1Router 5.5.5.5 5.5.5.5 1681 36 80000004 1Router 3.3.3.3 3.3.3.3 1770 84 80000015 1Network 45.1.1.4 4.4.4.4 1678 32 80000003 0Network 34.1.1.3 3.3.3.3 1738 32 80000003 0Sum-Net 23.1.1.0 3.3.3.3 1790 28 80000002 1Sum-Net 2.2.3.0 3.3.3.3 448 28 80000002 1Sum-Net 2.2.2.0 3.3.3.3 453 28 80000002 1Sum-Net 2.2.1.0 3.3.3.3 457 28 80000002 1Sum-Net 2.2.0.0 3.3.3.3 459 28 80000002 1Sum-Asbr 2.2.2.2 3.3.3.3 423 28 80000002 1AS External Database
Type LinkState ID AdvRouter Age Len Sequence Metric
External 12.1.1.0 2.2.2.2 425 36 80000002 10External 1.1.2.0 2.2.2.2 425 36 80000002 10External 1.1.3.0 2.2.2.2 425 36 80000002 10External 1.1.0.0 2.2.2.2 425 36 80000002 10External 1.1.1.0 2.2.2.2 425 36 80000002 10结果: 1. R4已经没有了关于2.2.3.0和3.3.3.0的路由,因为它在OSPF进程下,过滤了这些路由。
Routing Tables: Public
Destinations : 22 Routes : 22Destination/Mask Proto Pre Cost Flags NextHop Interface
1.1.0.0/24 O_ASE 150 10 D 45.1.1.4 GigabitEthernet0/0/1 1.1.1.0/24 O_ASE 150 10 D 45.1.1.4 GigabitEthernet0/0/1 1.1.2.0/24 O_ASE 150 10 D 45.1.1.4 GigabitEthernet0/0/1 1.1.3.0/24 O_ASE 150 10 D 45.1.1.4 GigabitEthernet0/0/1 2.2.0.0/24 OSPF 10 3 D 45.1.1.4 GigabitEthernet0/0/1 2.2.1.0/24 OSPF 10 3 D 45.1.1.4 GigabitEthernet0/0/1 2.2.2.0/24 OSPF 10 3 D 45.1.1.4 GigabitEthernet0/0/1 2.2.3.0/24 OSPF 10 3 D 45.1.1.4 GigabitEthernet0/0/1 3.3.0.0/24 OSPF 10 2 D 45.1.1.4 GigabitEthernet0/0/1 3.3.1.0/24 OSPF 10 2 D 45.1.1.4 GigabitEthernet0/0/1 3.3.2.0/24 OSPF 10 2 D 45.1.1.4 GigabitEthernet0/0/1 3.3.3.0/24 OSPF 10 2 D 45.1.1.4 GigabitEthernet0/0/1 12.1.1.0/24 O_ASE 150 10 D 45.1.1.4 GigabitEthernet0/0/1 23.1.1.0/24 OSPF 10 3 D 45.1.1.4 GigabitEthernet0/0/1 34.1.1.0/24 OSPF 10 2 D 45.1.1.4 GigabitEthernet0/0/1
<R5>display ospf lsdb
OSPF Process 110 with Router ID 5.5.5.5 Link State Database Area: 0.0.0.0
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 4.4.4.4 4.4.4.4 1369 48 80000009 1Router 5.5.5.5 5.5.5.5 1370 36 80000004 1Router 3.3.3.3 3.3.3.3 1461 84 80000015 1Network 45.1.1.4 4.4.4.4 1369 32 80000003 0Network 34.1.1.3 3.3.3.3 1428 32 80000003 0Sum-Net 23.1.1.0 3.3.3.3 1480 28 80000002 1Sum-Net 2.2.3.0 3.3.3.3 139 28 80000002 1Sum-Net 2.2.2.0 3.3.3.3 144 28 80000002 1Sum-Net 2.2.1.0 3.3.3.3 148 28 80000002 1Sum-Net 2.2.0.0 3.3.3.3 150 28 80000002 1Sum-Asbr 2.2.2.2 3.3.3.3 114 28 80000002 1AS External Database
Type LinkState ID AdvRouter Age Len Sequence Metric
External 12.1.1.0 2.2.2.2 116 36 80000002 10External 1.1.2.0 2.2.2.2 116 36 80000002 10External 1.1.3.0 2.2.2.2 116 36 80000002 10External 1.1.0.0 2.2.2.2 116 36 80000002 10External 1.1.1.0 2.2.2.2 116 36 80000002 10<R5>display ospf lsdb router 3.3.3.3
OSPF Process 110 with Router ID 5.5.5.5 Area: 0.0.0.0 Link State Database
Type : Router
Ls id : 3.3.3.3Adv rtr : 3.3.3.3 Ls age : 1498 Len : 84 Options : ABR E seq# : 80000015 chksum : 0xe197Link count: 5转载于:https://blog.51cto.com/liu008qing/2288023