Set up a Dedicated Interconnect link between the on-premises environment and Google Cloud:

Dedicated Interconnect provides a direct physical connection between your on-premises network and Google's network, which is ideal for high-throughput, low-latency connections.

Request a Dedicated Interconnect from the Google Cloud Console, specifying the required bandwidth and location.

Once provisioned, set up the connection on your on-premises router and configure the BGP sessions to exchange routes with Google Cloud.

Configure private access using the restricted.googleapis.com domains in on-premises DNS configurations:

Configure your on-premises DNS server to resolve Google APIs to restricted.googleapis.com. This ensures that the traffic stays within the Google network and is not exposed to the public internet.

Update your DNS settings to use restricted.googleapis.com for the necessary API endpoints.

This setup ensures that all Google Cloud API traffic is routed through the private link and subject to VPC Service Controls for additional security and compliance.