User Based Tunneling (UBT), a component of Dynamic Segmentation, creates a Centralized Overlay by tunneling specific user traffic from the access switch to a central Gateway (Controller) for centralized policy enforcement and inspection. The transport protocol used for this data tunnel is Generic Routing Encapsulation (GRE).

In contrast, EVPN-VXLAN is designed to create a Distributed Overlay fabric. It decouples the virtual network from the physical underlay, distributing Layer 3 gateways across leaf switches (Distributed Anycast Gateway). The VXLAN data plane encapsulates Layer 2 Ethernet frames within Layer 3 packets using UDP (specifically destination port 4789) to traverse the underlay network.

HPE Aruba Networking. (2023). ArubaOS-CX 10.13 Virtualization Guide. Chapter: "EVPN-VXLAN Solution Overview." (Confirming VXLAN uses UDP encapsulation and creates a distributed network fabric).

HPE Aruba Networking. (2022). Aruba Dynamic Segmentation on ArubaOS-CX Switch Guide. Section: "User-Based Tunneling (UBT)." (Describes the tunneling of traffic to a controller via GRE).

Mahalingam, M., et al. (2014). Virtual eXtensible Local Area Network (VXLAN): A Framework for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks. RFC 7348. (Official IETF standard defining VXLAN as a UDP-based encapsulation).