Configuring OSPF Stub Areas
By configuring non-backbone areas at the edge of ASs as stub areas, you can reduce the size of the routing table and number of LSAs to be transmitted.
Applicable Environment
The number of LSAs can be reduced by partitioning an AS into different areas. To reduce the number of entries in the routing table and the number of LSAs to be transmitted in a non-backbone area, configure the non-backbone area on the border of the AS as a stub area.
Configuring a stub area is optional.
Note the following points when configuring a stub area:
- The backbone area (Area 0) cannot be configured as a stub area.
- If an area needs to be configured as a stub area, all the routers in this area must be configured with stub attributes using the stub command.
- An ASBR cannot exist in a stub area. External routes are not transmitted in the stub area.
- Virtual links cannot exist in the stub area.