Your company is transitioning its entire workload to Google Cloud's Compute Engine. In this new cloud-based environment, certain servers must remain accessible via the Internet, while others should only be reachable through the internal network. Additionally, all servers, regardless of their access point, need to communicate with each other using specific ports and protocols. The existing on-premises network setup employs a demilitarized zone (DMZ) for public servers and a Local Area Network (LAN) for private servers. How would you design the networking architecture on Google Cloud to meet these requirements?