Filter-based GRE de-encapsulation

You can use generic routing encapsulation (GRE) to provide a private, secure path for transporting packets through a network by encapsulating (or tunneling) the packets, and you can configure a the supported device to de-encapsulate GRE traffic using a firewall filter. Because you don't need to create a tunnel interface to de-encapsulate the traffic with this method, this feature provides significant benefits in terms of scalability, performance and flexibility. For example, you can terminate many tunnels from multiple source IP addresses with one firewall term.