Configuring an Area as a Stub Area

Procedure

1. Run system-view

   The system view is displayed.

2. Run ospf [ process-id ]

   The OSPF process view is displayed.

3. Run area area-id

   The OSPF area view is displayed.

4. Run stub [ no-summary | default-route-advertise backbone-peer-ignore ] ^*

   The area is configured as a stub area.

   The parameter no-summary prevents an ABR from sending Type 3 LSAs to the stub area.

   The parameter default-route-advertise enables an ABR to generate default Type 3 LSAs and advertise them to the stub area.

   The parameter backbone-peer-ignore prevents an ABR from checking the neighbor status when the ABR generates default Type 3 LSAs and advertises them to the stub area. Specifically, the ABR generates default Type 3 LSAs and advertises them to the stub area if there is an Up interface in the backbone area.

   • Stub attributes must be configured on all switches in a stub area using the stub command.
   • Configuring or deleting stub attributes will update routing information in the area. Stub attributes can be deleted or reconfigured only after the routing update is complete.

5. (Optional) Run default-cost cost

   The cost of the default Type 3 route to the stub area is set.

   The default value is 1.

   To ensure the reachability of AS external routes to a stub area, the ABR in the stub area generates a default route and advertises the route to the non-ABR switches in the stub area.