Virtual eXtensible LAN is a network virtualization technology that uses a VLAN-like encapsulation technique to encapsulate OSI layer 2 Ethernet frames within layer 4 UDP datagrams, using 4789 as the default IANA-assigned destination UDP port number, although many implementations that predate the IANA assignment use port 8472.

a way to provide Ethernet-based multipoint to multipoint communication over IP or MPLS networks.