VXLAN is a technology that can be used to meet the requirement of using a legacy application that communicates at layer-2 across a layer-3 network. Static VXLAN is a feature that allows the creation of layer-2 overlay networks over a layer-3 underlay network using VXLAN tunnels. Static VXLAN does not require any control plane protocol or VTEP discovery mechanism, and can be configured manually on the Aruba CX 6200 switches. The other options are incorrect because they either do not support layer-2 communication over layer-3 network or are not supported by Aruba CX 6200 switches. Reference: https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch03.html https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch05.html