A company has a 1 Gbps Direct Connect link between its on-premises site and AWS. An on-prem application needs encrypted, private-IP communication with an application in a VPC. The traffic must not traverse the public internet. Which solution provides the required connectivity with the LEAST operational overhead?

The correct solution uses a Transit Gateway, a transit VIF on Direct Connect, and a Site-to-Site VPN. A transit VIF allows multiple VPCs (via Transit Gateway) to communicate with on-premises resources over Direct Connect. The Site-to-Site VPN provides the necessary encryption over the private Direct Connect link, fulfilling the requirement for encrypted, private-IP communication without traversing the public internet. This combination offers the least operational overhead for encrypted private connectivity. Option 1 is incorrect because a private VIF does not support native encryption, and a Site-to-Site VPN over a private VIF to a VGW is not a standard or efficient pattern for this requirement. Option 3 is incorrect because a public VIF is for public AWS services, not private IP communication with a VPC. Option 4 introduces a third-party firewall, which adds significant operational overhead and complexity compared to a native AWS VPN solution.