Google Professional Cloud Network Engineer Question 748
Select 3Google Cloud PlatformYou have configured a Cloud Router to establish a BGP session with your on-premises router, but the BGP session is not coming up. Upon reviewing the configuration, you discover the following details: the IP address of the on-premises router is correct, the BGP peer ASN is correctly set, and the firewall rules allow BGP traffic. Which of the following could be the reasons for the issue?
- A
The Cloud Router is not associated with a VPC network.
- B
The on-premises router is not advertising any routes.
- C
The Cloud Router's BGP interface IP address is misconfigured.
- D
There is a mismatch in the BGP hold timer configuration between the Cloud Router and the on-premises router.
- E
Cloud Router's region does not match the region of the resources it is supposed to route traffic to.
Show answer and explanation
Correct answers: A, C, D
Explanation
Troubleshooting BGP session issues requires checking both configuration and connectivity. A Cloud Router must be properly associated with a VPC network and configured with the correct BGP interface IP address. Additionally, protocol-level settings like the BGP hold timer must match between peers. Issues like the on-premises router not advertising routes or regional mismatches are unrelated to the establishment of the BGP session itself.
- A. Correct.
Correct. A Cloud Router must be associated with a VPC network to establish BGP sessions. Without this association, routing cannot function properly.
- B. Incorrect.
Incorrect. While the on-premises router not advertising routes could lead to no routes being learned, it would not prevent the BGP session itself from being established.
- C. Correct.
Correct. If the BGP interface IP address is incorrectly configured on the Cloud Router, the session with the on-premises router cannot be established.
- D. Correct.
Correct. A mismatch in the BGP hold timer configuration can cause the BGP session to fail to establish, as both peers must agree on the timer settings.
- E. Incorrect.
Incorrect. The region of the Cloud Router must match the region of its VPC subnetwork, but this does not impact the establishment of the BGP session.