What command is used to configure an OSPF area as a stub?

The command to configure an OSPF area as a stub is indeed the one that uses the syntax "area [area-id] stub." This command is essential for OSPF network design when you want to reduce the amount of routing information exchanged between routers in certain areas, particularly for enhancing performance and scalability.

By declaring an area as a stub, you limit the types of LSAs (Link State Advertisements) that are propagated into that area. Specifically, stub areas do not receive external routes, which helps to minimize the routing table size and the processing power required on routers within that area. Additionally, routers in a stub area will only receive Type 1 (Router) and Type 2 (Network) LSAs, while external routes (Type 5 LSAs) are not included. Stub areas also allow for a default route to be advertised into the area, which can be beneficial for reaching routes outside of the stub area without overwhelming the routers with excessive routing information.

The other options, while related to OSPF configuration, do not specifically serve the purpose of configuring a stub area. For instance, commands related to OSPF process identification or specifying network statements operate at different levels in OSPF configuration. The command for NSSA would