An engineer must establish a direct connection between two remote offices. The new connection must be established using a logical path, share a common broadcast domain, connect over private WAN, and…

Generic Routing Encapsulation (GRE) tunnels primarily extend Layer 3 routing domains, and while they can carry Layer 2 traffic with additional configuration (e.g., EoGRE), a native L2VPN offers a more direct and often more efficient solution for extending a broadcast domain.

Layer 2 VPN (L2VPN) technologies, such as VPLS or VPWS (EoMPLS), are explicitly designed to extend a Layer 2 broadcast domain across a wide area network. This directly fulfills the requirement for remote offices to share a common broadcast domain, typically over a private MPLS WAN, with efficient encapsulation.

Group Encrypted Transport VPN (GET VPN) is a Layer 3 encryption technology focused on securing existing routing infrastructure in a mesh, and it does not extend a Layer 2 broadcast domain.

IPsec is a Layer 3 security protocol that provides encryption and authentication for IP packets; it does not inherently extend a Layer 2 broadcast domain and would require additional tunneling mechanisms like GRE to carry Layer 2 traffic, adding more overhead.