Network Virtualization using Generic Routing Encapsulation

Network Virtualization using Generic Routing Encapsulation (NVGRE) is a network virtualization technology that attempts to alleviate the scalability problems associated with large cloud computing deployments. It uses Generic Routing Encapsulation (GRE) to tunnel layer 2 packets over layer 3 networks.

Source: Wikipedia — Network Virtualization using Generic Routing Encapsulation (CC BY-SA 4.0)