350-401 Question 452
Select 4In an OSPF network, a topology consists of multiple areas connected to the backbone area (Area 0). One of the routers is configured to redistribute routes learned from an external BGP connection into OSPF. Which of the following correctly describes the roles of the routers in the network?
- A
An ABR connects two or more OSPF areas, facilitating route exchange between them.
- B
An ASBR is responsible for redistributing external routes into OSPF.
- C
A backbone router is any router that has at least one interface in Area 0.
- D
An internal router is a router with all its interfaces within the same OSPF area.
- E
An ASBR must reside in Area 0 to redistribute external routes into OSPF.
Show answer and explanation
Correct answers: A, B, C, D
Explanation
In OSPF, different router types play specific roles. ABRs connect multiple areas, ASBRs import external routes, backbone routers ensure connectivity within Area 0, and internal routers are confined to a single area. ASBRs do not have to be in Area 0, as redistribution can occur in any area.
- A. Correct.
Correct: An ABR (Area Border Router) connects two or more OSPF areas and facilitates the exchange of routing information between them.
- B. Correct.
Correct: An ASBR (Autonomous System Boundary Router) is responsible for redistributing routes from external sources (e.g., BGP, EIGRP) into OSPF.
- C. Correct.
Correct: A backbone router is any router that has at least one interface in Area 0, which is the backbone area in OSPF.
- D. Correct.
Correct: An internal router is a router whose interfaces are all within the same OSPF area.
- E. Incorrect.
Incorrect: An ASBR does not need to reside in Area 0. It can exist in any area within the OSPF domain.