Which solution provides interoperability and protects data traffic from eavesdropping?

GET-VPN is a Cisco-proprietary group encryption solution designed for trusted MPLS or private WAN cores and does not provide cross-vendor interoperability.

Cisco MPLS TE is a traffic engineering mechanism that optimizes path selection in MPLS networks but provides no data encryption or protection against eavesdropping.

IPsec is an IETF open standard protocol suite (RFC 4301) that provides data confidentiality through encryption (AES, 3DES), integrity via HMAC, and peer authentication, making it interoperable across all vendor platforms. Because it is standards-based, any RFC-compliant device can establish IPsec tunnels with any other vendor's device. The encryption directly prevents eavesdropping on traffic in transit across untrusted networks.

DMVPN is a Cisco-proprietary overlay solution that simplifies hub-and-spoke VPN deployment but requires Cisco hardware and is not an open-standard interoperable technology.