300-420 Question 40
Single answerA company is designing a BGP-based network with multiple internal BGP (iBGP) routers. To optimize scalability, the network architect decides to implement route reflectors. Which of the following statements is TRUE regarding the use of route reflectors in this network?
- A
Route reflectors reduce the need for a full iBGP mesh by allowing selected routers to forward routes to other iBGP peers.
- B
Route reflectors eliminate the need for any iBGP sessions between clients.
- C
Route reflectors require all clients to advertise routes only to the route reflector, not to any other clients.
- D
Route reflectors must be deployed in pairs to ensure redundancy in the network.
Show answer and explanation
Correct answer: A
Explanation
Route reflectors are used in iBGP to reduce the number of iBGP sessions required in a full mesh topology. By allowing specific routers to act as reflectors, route information is forwarded from one client to another without requiring direct sessions between all iBGP peers. This significantly improves scalability in large networks. However, route reflectors do not eliminate the need for all iBGP sessions, and deploying them in pairs for redundancy, while a best practice, is not a strict requirement.
- A. Correct.
This statement is correct. Route reflectors allow selected routers (reflectors) to forward routes to other iBGP peers, reducing the number of iBGP sessions required in a full mesh topology.
- B. Incorrect.
This statement is incorrect. While route reflectors reduce the number of iBGP sessions required, they do not eliminate the need for all iBGP sessions entirely. Route reflector clients still need to establish sessions with their reflectors.
- C. Incorrect.
This statement is incorrect. While clients must advertise routes to their route reflector, they may also advertise routes to other clients directly if needed. The route reflector mechanism does not prohibit this.
- D. Incorrect.
This statement is incorrect. While deploying route reflectors in pairs is a common practice for redundancy, it is not a mandatory requirement for route reflector functionality.