=====GRE=====
**G**eneric **R**outing **E**ncapsulation protocol can be used as logical point-to-point links, encapsulating most any traffic over a tunnel as unicast. The unicast feature being useful over IPSEC as IPSEC only works over unicast traffic.

====Configuration Example====
Assuming all destinations are routable -- creating a basic GRE Tunnel over the following topology: