350-401 Question 444
Single answerYou are designing an OSPF network for a large enterprise. The network includes multiple branch offices connected to the headquarters through a single WAN link. To optimize routing, you want to minimize the size of the OSPF routing table on the branch routers while still allowing the branches to reach external networks through the headquarters. Which OSPF area type should you configure for the branch offices?
- A
Backbone Area (Area 0)
- B
Stub Area
- C
Totally Stubby Area
- D
Not-So-Stubby Area (NSSA)
Show answer and explanation
Correct answer: C
Explanation
Totally Stubby Areas are ideal for branch offices with limited resources or simple routing requirements. By replacing all external and inter-area routes with a single default route, they minimize the size of the routing table on branch routers, meeting the objective of this scenario.
- A. Incorrect.
Backbone Area (Area 0) is the central area in OSPF and cannot be used for branch offices in this scenario. All OSPF areas must connect to Area 0, but it is not designed for minimizing routing tables on branch routers.
- B. Incorrect.
Stub Area reduces external routes by replacing them with a default route. However, it still includes inter-area routes, which may not fully minimize the routing table size.
- C. Correct.
Totally Stubby Area is the best choice as it replaces both external and inter-area routes with a default route, minimizing the routing table size on branch routers.
- D. Incorrect.
Not-So-Stubby Area (NSSA) is used when you need to allow external route redistribution into an OSPF stub-like area, which is not a requirement in this scenario.