Google PCA Design and plan a cloud solution architecture Practice Question

Correct answer & explanation

The Cloud SQL instance has authorized networks set to 0.0.0.0/0, which allows all IPs. However, the instance has a public IP, and the VM has an external IP. The connection fails with timeout, suggesting that the traffic is not reaching the database. This could be due to the database not having SSL enforced, but that would cause a different error. The most likely cause is that the Cloud SQL instance is not configured to allow connections from the VM's public IP, because authorized networks only apply to connections using the public IP. But the exhibit shows it's set to 0.0.0.0/0, so that should work. Another possibility: the VM is trying to connect to the private IP of the Cloud SQL instance, but the instance does not have a private IP. The exhibit shows '--assign-ip' which assigns a public IP, but does not assign a private IP. The VM might be trying to connect to the private IP, which doesn't exist. However, the error is 'connection timed out', which suggests the client cannot reach the IP. If the client is using the public IP, the firewall on the VM allows egress. The issue could be that the Cloud SQL instance's public IP is not reachable from the VM's network due to VPC firewall rules? But the VM's firewall allows egress to 0.0.0.0/0. The most likely cause is that the Cloud SQL instance does not have a private IP, and the VM is trying to connect via private IP. But the user might be using the correct public IP. Another common issue: the Cloud SQL instance requires SSL, but the client is not using SSL. However, that would give a different error like 'SSL required'. The timeout suggests network connectivity. Given the exhibit, the Cloud SQL instance has only a public IP and authorized networks allow all IPs, so the issue is likely that the VM is trying to connect using the instance's private IP, which doesn't exist. Alternatively, the VM might be in a different VPC and peering is not set up. But the question says 'different VPC'. Since the instance has a public IP, the VM can connect via public IP regardless of VPC. The most plausible answer is that the Cloud SQL instance does not have a private IP, and the user is trying to connect to the private IP. However, the exhibit doesn't show the connection string. Another possibility: the user has not enabled public IP access from the VM's network? No, authorized networks allow all. I think the intended answer is that the Cloud SQL instance does not have a private IP, so the VM, if using private IP, cannot connect. But the question says 'connection fails', so we need to infer. Let me craft options.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.