300-410 Question 111
Select 3In an OSPF network, you are tasked with understanding the roles of different router types. A router in Area 0 is responsible for summarizing routes from Area 1 and redistributing external routes learned from a BGP peer into the OSPF domain. Which roles does this router fulfill?
- A
Internal Router
- B
Backbone Router
- C
Area Border Router (ABR)
- D
Autonomous System Boundary Router (ASBR)
- E
Designated Router (DR)
Show answer and explanation
Correct answers: B, C, D
Explanation
The router resides in Area 0, fulfilling the Backbone Router role. It summarizes routes from Area 1, making it an ABR, and redistributes external routes from BGP, qualifying it as an ASBR. It is not an Internal Router as it operates across multiple areas, and there is no indication it serves as a DR on a multi-access network.
- A. Incorrect.
An Internal Router is a router that resides entirely within a single OSPF area and does not summarize or redistribute routes from other areas or external sources. This does not apply to the described router.
- B. Correct.
A Backbone Router is any router that has at least one interface in Area 0. Since the described router is in Area 0, it fulfills this role.
- C. Correct.
An ABR is a router that connects multiple OSPF areas (e.g., Area 0 and Area 1) and summarizes routes between them. The described router summarizes routes from Area 1, making it an ABR.
- D. Correct.
An ASBR is a router that redistributes routes from external sources (e.g., BGP) into the OSPF domain. Since the router redistributes external routes from a BGP peer, it fulfills the ASBR role.
- E. Incorrect.
A Designated Router (DR) is elected on multi-access networks to reduce OSPF overhead. The scenario does not mention the router being a DR, so this role does not apply.