You just finished your company's migration to Google Cloud and configured an architecture with 3 Virtual Private Cloud (VPC) networks: one for Sales, one for Finance, and one for Engineering. Every…

Configuring an HA VPN gateway between two VPCs within the same Google Cloud environment is overly complex, introduces additional costs, and typically results in higher latency and lower throughput compared to VPC Network Peering for intra-cloud connectivity.

Configuring instances with external IP addresses and routing traffic over the public internet compromises security by exposing instances to the internet and introduces unpredictable performance, directly failing the requirement for private and secure communication.

Creating a VPC Network Peering connection between the Finance VPC and the Sales VPC enables private IP communication directly between instances in these two networks. This method offers high-bandwidth, low-latency connectivity, operates entirely within Google's private network infrastructure for enhanced security, and does not incur additional charges for network traffic between peered VPCs.

Configuring Cloud NAT and a Cloud Router is used for outbound internet access from private instances (NAT) or establishing hybrid connectivity to on-premises networks (Cloud Router), not for direct private communication between two distinct VPCs within Google Cloud.