You want to allow RIP routes to be redistributed by an ASBR into the connected OSPF area. Which OSPF area type would be used to satisfy the requirement?

To enable redistribution of RIP routes into an OSPF area through an Autonomous System Boundary Router (ASBR), a Not-So-Stubby Area (NSSA) is the appropriate choice. NSSA allows for route redistribution from an external protocol like RIP into the OSPF domain while maintaining OSPF's hierarchical design.

In detail, NSSA is a variation of a stub area that allows external routes to be imported, but it's limited to only those external routes and not the entire OSPF routing table. It ensures that internal OSPF routes remain unaffected while still allowing selected external routing information to be utilized. This makes it possible for the ASBR to advertise RIP routes into the OSPF network without compromising the area’s stub characteristics.

In contrast, stub areas and totally stubby areas will block external routing information and limit the types of routes that can be advertised, making them unsuitable for the requirement to redistribute RIP routes. A transit area is designed to facilitate the passage of OSPF packets between different OSPF areas and doesn’t inherently support the redistribution of routes from other protocols. Thus, selecting a Not-So-Stubby Area is essential to achieve the desired integration of RIP into the OSPF routing environment properly.