Switches and routers technology - 26 - configure OSPF peripheral area

Margin area

There is only one default route, which is the exit of the area

The area cannot be used as the traversing area of ​​the virtual link (if the non-backbone area is connected to the backbone area and cannot be directly connected, you need to traverse a certain area and configure the virtual linklink)

There is no autonomous system border router ASBR in the stub area

Not the backbone area 0

Features

No LSA4,5,7 in the distal area

Fully distal area

LSA3 advertisement except for one default route, no LSA3, 4, 5, 7

Purpose: Reduce link state advertisements in the area

Configure the stub routing, a default route will be automatically generated on router 2/3

Disable routing state summary information on inter-area ABR routers

Conf t

Router ospf 10

Area 2 stub no-summary Each area 2 router needs to configure this command

Indicates that it is configured as a complete peripheral area, and the routing information of inter-area AI will not be learned

Summary of ideas:

Build topology, divide network segments and configure IP for each interface

Announce network segment for each route, set area, close route summary

Router 0Router(config)#router ospf 10Router(config-router)#network 192.168.10.0 0.0.0.255 area 0router 1Router(config)#router ospf 10Router(config-router)#network 192.168.10.0 0.0.0.255 area 0Router(config-router)#network 192.168.10.0 0.0.0.255 area 2Router(config-router)#area 2 stubRouter(config-router)#area 2 stub no-summary //Turn off route summarization and configure complete stub arearouter 2Router(config)#router ospf 10Router(config-router)#network 192.168.30.0 0.0.0.255 area 2Router(config-router)#area 2 stubRouter(config-router)#area 2 stub no-summary //Turn off route summarization and configure complete stub arearouter 3Router(config)#router ospf 10Router(config-router)#network 192.168.40.0 0.0.0.255 area 2Router(config-router)#area 2 stubRouter(config-router)#area 2 stub no-summary //Turn off route summary and configure complete stub area