Which method must be used to connect on-premises networks to Google Cloud while ensuring secure access to Google APIs?

To ensure secure access to Google APIs while connecting on-premises networks to Google Cloud, using a Dedicated Interconnect link is the most effective method. Dedicated Interconnect provides a private, physical connection between on-premises infrastructure and Google Cloud, which enhances security by eliminating exposure to the public Internet. This direct link ensures a high-performance connection with lower latency and increased bandwidth, making it suitable for transferring sensitive data and accessing Google services securely.

In contrast, a VPN connection typically uses the public Internet to establish a secure tunnel. While it does provide encryption and secure access, it may not offer the same level of bandwidth or stability as a Dedicated Interconnect option for high-volume traffic or latency-sensitive applications.

Configuring a public API endpoint generally exposes Google services over the Internet, which does not inherently secure access to data or APIs. Similarly, using SSH tunnels could provide secure access but is more suitable for specific use cases rather than a comprehensive connection between on-premises environments and Google Cloud.

Overall, the Dedicated Interconnect link is specifically designed to cater to the needs of organizations requiring robust security, performance, and reliability when interfacing with Google Cloud services.