2V0-41.24 Question 331
Select 3An organization is configuring BGP on a Tier-0 Gateway in their VMware NSX environment. They need to establish a BGP peering session between the Tier-0 Gateway and an external router. During configuration, the network administrator notices that the BGP session remains in an 'Idle' state. Which of the following actions should the administrator take to troubleshoot and resolve the issue?
- A
Ensure that the remote BGP peer IP address is reachable from the Tier-0 Gateway.
- B
Verify that the Autonomous System (AS) number configured on the Tier-0 Gateway matches the external router's AS number.
- C
Confirm that the same authentication method and passwords are configured on both the Tier-0 Gateway and the external router if BGP authentication is enabled.
- D
Check if the Tier-0 Gateway is configured with a proper BGP redistribution policy to advertise routes.
- E
Ensure that the BGP neighbor configuration on the external router has the correct source IP address for the Tier-0 Gateway.
Show answer and explanation
Correct answers: A, C, E
Explanation
When troubleshooting a BGP session stuck in 'Idle', the primary focus should be on connectivity, neighbor configuration, and authentication. Ensuring the peer IP is reachable, matching authentication credentials, and verifying the neighbor configuration on the external router are essential steps. Redistribution policies and AS number matching are unrelated to the establishment of the BGP session and are not relevant to resolving this issue.
- A. Correct.
The remote BGP peer IP address must be reachable for the BGP session to transition from 'Idle' to 'Active' and eventually 'Established'. If the IP is unreachable, the session will remain in 'Idle'.
- B. Incorrect.
The AS number of the Tier-0 Gateway does not need to match the external router's AS number unless the two devices are part of the same AS. In most cases, they will be different, so this is not a valid troubleshooting step.
- C. Correct.
If BGP authentication is enabled, the same method (e.g., MD5) and credentials must be configured on both sides. A mismatch will cause the session to fail.
- D. Incorrect.
While a redistribution policy is important for route advertisement, it does not impact the establishment of a BGP session. Therefore, this is not relevant to resolving the 'Idle' state.
- E. Correct.
The external router must be configured with the correct source IP address for the Tier-0 Gateway. If the source IP is incorrect, the BGP session will not establish.