You must recreate an on-prem hub-and-spoke (50+ spokes) architecture in Google Cloud: spokes cannot talk to each other and all traffic goes through the hub. Minimize management overhead and cost using default quotas and limits. What should you do?

The correct answer uses Cloud VPN and a third-party appliance. Cloud VPN allows secure connections from each spoke VPC to the central hub VPC. The third-party network appliance in the hub acts as a centralized gateway, enforcing the "no spoke-to-spoke" communication rule by inspecting and routing all traffic. This design minimizes management overhead because routing policies are centralized on the appliance, and it uses standard Google Cloud services. Connecting all spokes to the hub with Cloud VPN alone would still allow spoke-to-spoke communication if routes are exchanged, which violates the requirement. VPC Network Peering allows direct spoke-to-spoke communication by default, making it unsuitable for the "no spoke-to-spoke" requirement without complex firewall rules, which increases management overhead. Even with a third-party appliance, VPC Network Peering's default behavior makes it less ideal for this specific constraint compared to Cloud VPN.