目录 提要 正文 TOPO如下 基本配置如下 验证 附注

提要： 讨论 OSPF ABR Type 3 LSA Filtering cisco文档关于OSPF ABR Type 3 LSA Filtering的解释 正文： OSPF ABR Type 3 LSA Filtering只能在ABR上面做 TOPO如下： 基本配置如下： l R1 l R2 l R3 R1 interface Loopback0 ip address 1.1.1.1 255.255.255.0 ip ospf network point-to-point ! interface Serial1/0 ip address 12.1.1.1 255.255.255.0 serial restart-delay 0 no fair-queue ! interface Serial2/0 ip address 13.1.1.1 255.255.255.0 serial restart-delay 0 ! router ospf 1 router-id 1.1.1.1 log-adjacency-changes network 12.1.1.0 0.0.0.255 area 0 network 13.1.1.0 0.0.0.255 area R2 interface Loopback0 ip address 2.2.2.2 255.255.255.0 ! interface Serial2/0 ip address 12.1.1.2 255.255.255.0 serial restart-delay 0 ! router ospf 1 router-id 2.2.2.2 log-adjacency-changes network 12.1.1.0 0.0.0.255 area 0 R3 interface Loopback0 ip address 3.3.0.3 255.255.255.0 secondary ip address 3.3.1.3 255.255.255.0 secondary ip address 3.3.2.3 255.255.255.0 secondary ip address 3.3.3.3 255.255.255.0 ip ospf network point-to-point ! interface Serial1/0 ip address 13.1.1.3 255.255.255.0 serial restart-delay 0 no fair-queue ! router ospf 1 log-adjacency-changes network 3.3.0.0 0.0.255.255 area 1 network 13.1.1.0 0.0.0.255 area 1 测试： 没有配置lsa type3过滤器之前 查看r2路由表 r2#sho ip route | begin Ga Gateway of last resort is not set 2.0.0.0/24 is subnetted, 1 subnets C 2.2.2.0 is directly connected, Loopback0 3.0.0.0/24 is subnetted, 4 subnets O IA 3.3.0.0 [110/129] via 12.1.1.1, 00:00:51, Serial2/0 O IA 3.3.1.0 [110/129] via 12.1.1.1, 00:00:57, Serial2/0 O IA 3.3.2.0 [110/129] via 12.1.1.1, 00:00:57, Serial2/0 O IA 3.3.3.0 [110/129] via 12.1.1.1, 00:00:45, Serial2/0 12.0.0.0/24 is subnetted, 1 subnets C 12.1.1.0 is directly connected, Serial2/0 13.0.0.0/24 is subnetted, 1 subnets O IA 13.1.1.0 [110/128] via 12.1.1.1, 00:10:40, Serial2/0 配置过滤器 过滤掉3.3.3.0/24 r1(config)#ip prefix-list area1-out seq 10 deny 3.3.3.0/24 r1(config)#ip prefix-list area1-out seq 15 permit 0.0.0.0/0 le 32 r1(config-router)#area 1 filter-list prefix area1-out out 查看r1的数据库area 0中 没有3.3.3.3 1#sho ip os da OSPF Router with ID (1.1.1.1) (Process ID 1) Router Link States (Area 0) Link ID ADV Router Age Seq# Checksum Link count 1.1.1.1 1.1.1.1 11 0x80000006 0x00F080 2 2.2.2.2 2.2.2.2 1909 0x80000004 0x0091DD 2 Summary Net Link States (Area 0) Link ID ADV Router Age Seq# Checksum 3.3.0.0 1.1.1.1 406 0x80000004 0x00A648 3.3.1.0 1.1.1.1 411 0x80000001 0x00A14F 3.3.2.0 1.1.1.1 411 0x80000001 0x009659 13.1.1.0 1.1.1.1 11 0x80000004 0x0027BF 查看r2的路由表 没有3.3.3.0/24的条目 r2#sho ip route | begin Ga Gateway of last resort is not set 2.0.0.0/24 is subnetted, 1 subnets C 2.2.2.0 is directly connected, Loopback0 3.0.0.0/24 is subnetted, 3 subnets O IA 3.3.0.0 [110/129] via 12.1.1.1, 00:07:55, Serial2/0 O IA 3.3.1.0 [110/129] via 12.1.1.1, 00:08:01, Serial2/0 O IA 3.3.2.0 [110/129] via 12.1.1.1, 00:08:01, Serial2/0 12.0.0.0/24 is subnetted, 1 subnets C 12.1.1.0 is directly connected, Serial2/0 13.0.0.0/24 is subnetted, 1 subnets O IA 13.1.1.0 [110/128] via 12.1.1.1, 00:17:45, Serial2/0 －－－－－－－－－－－－－－－－－－－－－－－－－－ 以下检验area range与lsa 类型3 过滤器之间的联系 If the area range command has been configured for this area, type 3 LSAs that correspond to the area range are sent to all other areas, only if at least one prefix in the area range matches an entry in the prefix list. If all specific prefixes are denied by the prefix list, type 3 LSAs that correspond to the area range command will not be sent to any other area. Prefixes that are not permitted by the prefix list are implicitly denied.――载自文档 在R1做汇总 r1(config-router)#area 1 range 3.3.0.0 255.255.252.0 r2#sho ip route | be Ga Gateway of last resort is not set 2.0.0.0/24 is subnetted, 1 subnets C 2.2.2.0 is directly connected, Loopback0 3.0.0.0/22 is subnetted, 1 subnets O IA 3.3.0.0 [110/129] via 12.1.1.1, 00:04:31, Serial2/0 12.0.0.0/24 is subnetted, 1 subnets C 12.1.1.0 is directly connected, Serial2/0 13.0.0.0/24 is subnetted, 1 subnets O IA 13.1.1.0 [110/128] via 12.1.1.1, 00:23:50, Serial2/0 在r1上增加几句 prefix-list把3.3.0.0所有网段都排除 r1(config)#ip prefix-list area1-out seq 11 deny 3.3.0.0/24 r1(config)#ip prefix-list area1-out seq 12 deny 3.3.1.0/24 r1(config)#ip prefix-list area1-out seq 13 deny 3.3.2.0/24 查看r2路由表，那条汇总路由3.0.0.0/22 没有了 r2#sho ip route | be Ga Gateway of last resort is not set 2.0.0.0/24 is subnetted, 1 subnets C 2.2.2.0 is directly connected, Loopback0 12.0.0.0/24 is subnetted, 1 subnets C 12.1.1.0 is directly connected, Serial2/0 13.0.0.0/24 is subnetted, 1 subnets O IA 13.1.1.0 [110/128] via 12.1.1.1, 00:31:35, Serial2/0 结论：如果所有明细的路由都被禁止了，汇总也会没掉

怎么都是实验,就这个结论：如果所有明细的路由都被禁止了，汇总也会没掉