Google Professional Cloud Network Engineer Question 725
Select 4Google Cloud PlatformYour organization has a three-tier application deployed on Google Cloud. The frontend is hosted on a managed instance group behind a global external HTTP(S) load balancer. The backend services are running on Compute Engine VMs in a shared VPC. Recently, users started reporting intermittent connectivity issues when accessing the application. You need to troubleshoot the issue. Which of the following steps should you take to identify and resolve the connectivity problem?
- A
Check the health check status of the backend instances in the load balancer configuration.
- B
Review the firewall rules to ensure they allow the traffic from the load balancer to the backend instances.
- C
Inspect the routes in the VPC to verify that they correctly direct traffic to the backend instances.
- D
Enable VPC Service Controls to restrict unauthorized access to the backend services.
- E
Use Cloud Logging and Monitoring to analyze the logs and metrics for the affected services.
Show answer and explanation
Correct answers: A, B, C, E
Explanation
To troubleshoot the connectivity problem, it’s essential to validate the health check configuration, firewall rules, and routes in the VPC, as they directly impact the ability of the load balancer to route traffic to the backend instances. Additionally, Cloud Logging and Monitoring can provide insights into the problem through logs and metrics. VPC Service Controls, while important for security, are not directly relevant to resolving connectivity issues in this scenario.
- A. Correct.
Correct: If the backend instances fail the health checks, the load balancer will not send traffic to them, resulting in connectivity issues.
- B. Correct.
Correct: Firewall rules must allow traffic from the load balancer to the backend instances. Misconfigured rules can block the traffic, causing connectivity issues.
- C. Correct.
Correct: Incorrect or missing routes in the VPC can prevent traffic from reaching the backend instances, leading to connectivity problems.
- D. Incorrect.
Incorrect: VPC Service Controls are used to enhance security by limiting access to services. While useful, this is not a direct troubleshooting step for connectivity issues.
- E. Correct.
Correct: Cloud Logging and Monitoring provide logs and metrics that can help identify the root cause of the connectivity problems, such as errors or resource bottlenecks.