1、特殊区域stub解析

区域类型	作用	是否下发默认路由	备注
stub	过滤LSA4、LSA5	ABR默认下发3类默认路由，seed cost值为1	本区域所有路由器都必须配置成stub，否则邻居起不来，且不能包含ASBR

2、实验拓扑

3、实验配置

R1配置

interface Loopback0

 ip address 1.1.1.1 255.255.255.0

interface Serial0/0

 ip address 12.1.1.1 255.255.255.0

router ospf 110

 router-id 1.1.1.1

 network 12.1.1.0 0.0.0.255 area 2

R2配置

interface Loopback0

 ip address 2.2.2.2 255.255.255.0

interface Serial0/0

 ip address 12.1.1.2 255.255.255.0

interface Serial0/1

 ip address 23.1.1.2 255.255.255.0router ospf 110

 router-id 2.2.2.2

 network 12.1.1.0 0.0.0.255 area 2

 network 23.1.1.0 0.0.0.255 area 0

R3配置

interface Loopback0

 ip address 3.3.3.3 255.255.255.0

interface Serial0/0

 ip address 34.1.1.3 255.255.255.0

interface Serial0/1

 ip address 23.1.1.3 255.255.255.0router ospf 110

 router-id 3.3.3.3

 network 23.1.1.0 0.0.0.255 area 0

 network 34.1.1.0 0.0.0.255 area 1

R4配置

interface Loopback0

 ip address 4.4.4.4 255.255.255.0

interface Serial0/0

 ip address 34.1.1.4 255.255.255.0

interface Serial0/1

 ip address 45.1.1.4 255.255.255.0

router ospf 110

 router-id 4.4.4.4

 redistribute rip subnets

 network 34.1.1.0 0.0.0.255 area 1

R5配置

interface Loopback0

 ip address 5.5.5.5 255.255.255.0

interface Serial0/1

 ip address 45.1.1.5 255.255.255.0

 serial restart-delay 0

router rip

 version 2

 network 5.0.0.0

 network 45.0.0.0

 no auto-summary

4、实验验证

过滤LSA4、LSA4

配置stub前

配置stub后

ABR下放3类默认路由

5、修改重分布后的cost值，默认值为1