Exam Professional Cloud Developer topic 1 question 4 discussion

C the source IP ranges for health checks (including legacy health checks if used for HTTP(S) Load Balancing) are: 35.191.0.0/16 130.211.0.0/22 Furthermore it should be direction INGRESS since the health-check (ping) is coming into the load balancer/instance. source: https://cloud.google.com/load-balancing/docs/health-checks

Option C is the correct choice because it addresses the issue of health check failures for the Compute Engine instances behind the HTTP(s) Load Balancer. By creating an ingress firewall rule, this command allows traffic from the load balancer’s source IP ranges to reach the instances on the specified network. These source IP ranges (130.211.0.0/22 and 35.191.0.0/16) are used by Google Cloud load balancers for health checking. Without this rule, the health checks would fail because the load balancer could not communicate with the backend instances to verify their status, resulting in no traffic being routed to those instances. By implementing this firewall rule, you ensure that the health check traffic is permitted, which should resolve the traffic routing issue and allow the load balancer to function correctly.

I would go with C.

To resolve the problem, you should run the following command: Copy code gcloud compute firewall-rules create allow-lb --network load-balancer --allow tcp --source-ranges 130.211.0.0/22,35.191.0.0/16 --direction INGRESS This will create a firewall rule that allows incoming TCP traffic from the specified IP ranges to the Load Balancer network. This should allow traffic to reach the instance group and the instances it contains. Option A will not help because it is used to add an external IP address to an instance, which is not necessary for the Load Balancer to work. Option B is not necessary because it is used to apply metadata to an instance, which is not related to the Load Balancer. Option D is not correct because it allows outgoing traffic from the Load Balancer network, which is not necessary for the Load Balancer to work. I hope this helps! Let me know if you have any other questions.

C is correct

C ingress not egress

I would say B with predefined http-server tag on instance.

I choose C.