300-420 Question 37
Select 2An enterprise network is deploying a BGP Route Reflector (RR) architecture to optimize scalability in its network. The network engineer notices that some IBGP routes are not being propagated to all IBGP peers. Upon investigation, it is found that some routes are dropped due to a loop prevention mechanism. Which of the following actions can resolve this issue while maintaining the Route Reflector design?
- A
Ensure the Cluster ID is unique for each Route Reflector.
- B
Configure the 'no synchronization' command on all IBGP peers.
- C
Verify that the Originator ID attribute is correctly set on routes.
- D
Configure additional Route Reflectors to distribute the load.
- E
Enable the 'next-hop-self' command on the Route Reflector.
Show answer and explanation
Correct answers: A, C
Explanation
In a BGP Route Reflector architecture, loop prevention is managed using the Cluster ID and Originator ID attributes. Ensuring that the Cluster ID is unique across Route Reflectors prevents loops and avoids dropping valid routes. Additionally, the Originator ID ensures that routes are not reflected back to their origin, which is another critical part of loop prevention. These configurations help maintain a functional and scalable IBGP network with Route Reflectors.
- A. Correct.
Using a unique Cluster ID for each Route Reflector prevents route loops in the network. If multiple Route Reflectors have the same Cluster ID, BGP loop prevention could mistakenly drop valid routes.
- B. Incorrect.
The 'no synchronization' command disables the synchronization between IBGP and IGP, but it does not address the route loop prevention mechanism caused by misconfigured Route Reflector attributes.
- C. Correct.
The Originator ID attribute ensures that the Route Reflector does not re-advertise routes back to their origin. Incorrectly set Originator IDs can cause valid routes to be dropped.
- D. Incorrect.
Adding more Route Reflectors can help with scalability but does not directly address the loop prevention mechanism causing route drops.
- E. Incorrect.
Enabling 'next-hop-self' modifies the next-hop attribute for routes but does not resolve issues related to the BGP loop prevention mechanism.