This is because VXLAN is a network virtualization technology that encapsulates Layer 2 frames in UDP headers and allows them to be transported over Layer 3 networks. VXLAN is used in Cisco SD-Access to create virtual networks that span across multiple physical locations and devices. VXLAN performs the data plane forwarding function, which is responsible for moving packets from one point to another based on the destination address. The source of this answer is the Cisco ENCOR v1.1 course, module 9, lesson 9.2: Implementing VXLAN.