350-401 Question 486
Single answerA company is deploying a BGP route reflector in its network to reduce the number of BGP peer connections required on its routers. After configuring the route reflector and client routers, you notice that the route reflector is successfully advertising routes to the clients, but client-to-client communication is failing. What is the most likely cause of this issue?
- A
The route reflector is not configured to reflect routes between clients.
- B
The clients are not configured with the route reflector as their iBGP peer.
- C
The route reflector is not injecting the routes into the IGP.
- D
The clients are not configured to accept reflected routes from the route reflector.
Show answer and explanation
Correct answer: A
Explanation
In a BGP route reflector setup, the route reflector reflects routes learned from one client to other clients. If the route reflector is not correctly reflecting these routes, client-to-client communication will fail. This behavior is central to how route reflectors reduce the full mesh requirement in iBGP. Ensuring the route reflector is properly configured to perform its role resolves the issue.
- A. Correct.
A route reflector must be configured to reflect routes between its client routers. By default, route reflectors reflect routes advertised from one client to other clients. If this configuration is missing or incorrect, client-to-client communication will fail.
- B. Incorrect.
This is incorrect because the clients must indeed be configured with the route reflector as their iBGP peer, but the problem in this scenario is related to route reflection itself.
- C. Incorrect.
Route reflection is a BGP-specific mechanism and does not involve injecting routes into the IGP. This is not the cause of the issue.
- D. Incorrect.
Clients automatically accept reflected routes from the route reflector as long as the BGP session is correctly established. No additional configuration is required for this.