A green data center is being deployed and a design requirement is to be able to readily scale server virtualization. Which IETF standard technology can provide this requirement?

TRILL is an IETF standard (RFC 6325) designed to overcome spanning tree limitations by enabling multi-path forwarding at Layer 2, which is essential for scaling server virtualization across large data center fabrics. It allows VMs to migrate freely across the network while supporting load balancing and eliminating STP convergence issues. This makes it the correct IETF-standard choice for scalable virtualization environments.

Fabric Path is Cisco's proprietary implementation inspired by TRILL concepts, not an IETF standard technology.

Data Center Bridging (DCB) is an IEEE standard suite focused on providing lossless Ethernet for storage and converged traffic, not on scaling server virtualization.

Unified Fabric is a Cisco marketing concept for converged network infrastructure, not a specific IETF standard technology.