Generic routing encapsulation (GRE)
GRE – Generic Routing Encapsulation, provides a private path for transporting packet between two remote sites across providers network
GRE provides a private path for transporting packets through an otherwise public network by encapsulating (or tunneling) the packets. GRE tunneling is accomplished through tunnel endpoints that encapsulate or de-encapsulate traffic.
- Underlay network configuration ( ISP)
- Overlay network (Customer)
- Tunnel subnet