Multi-region VPC has an HA VPN in region 1. You will add two 10 Gbps Dedicated Interconnect VLAN attachments in region 2 to the same on-prem network. Ensure traffic prefers Dedicated Interconnect and uses HA VPN as failover. What should you do?

To ensure traffic prefers Dedicated Interconnect (DI) and uses HA VPN as failover across regions, global dynamic routing is essential. Global dynamic routing allows routes learned in one region (like from the DI in region 2) to be advertised to all other regions in the VPC, including where the HA VPN is (region 1). The base priority in Google Cloud BGP influences the local preference attribute advertised to Google Cloud routers. A lower base priority value indicates a higher preference. Therefore, setting the VLAN-attachment BGP (Dedicated Interconnect) with a base priority of 100 makes it the preferred path. The HA VPN BGP in region 1 should have a higher base priority (e.g., 20000) to act as a less preferred, failover path. Setting similar MED values on on-prem routers prevents the on-premise network from influencing path selection based on MED, ensuring Google Cloud's BGP priorities dictate the primary and failover routes. Regional dynamic routing would prevent the DI routes from being advertised to the HA VPN region, making failover impossible. Incorrect base priority assignments would reverse the desired traffic preference.