OSPF ABR Type 3 LSA Filtering
Document ID: 00007
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目录
提要
正文
TOPO如下
基本配置如下
验证
附注
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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
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
C
O IA
O IA
O IA
O IA
C
O IA
配置过滤器 过滤掉
r1(config)#ip prefix-list area1-out seq 10 deny
r1(config)#ip prefix-list area1-out seq 15 permit
r1(config-router)#area 1 filter-list prefix area1-out out
查看r1的数据库area 0中 没有
1#sho ip os da
OSPF Router with ID (
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
查看r2的路由表 没有
r2#sho ip route | begin Ga
Gateway of last resort is not set
C
O IA
O IA
O IA
C
O IA
--------------------------
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
r2#sho ip route | be Ga
Gateway of last resort is not set
C
O IA
C
O IA
在r1上增加几句 prefix-list把
r1(config)#ip prefix-list area1-out seq 11 deny
r1(config)#ip prefix-list area1-out seq 12 deny
r1(config)#ip prefix-list area1-out seq 13 deny
查看r2路由表,那条汇总路由
r2#sho ip route | be Ga
Gateway of last resort is not set
C
C
O IA
结论:如果所有明细的路由都被禁止了,汇总也会没掉 |