Palo Alto Networks next-generation firewalls
can now terminate generic routing encapsulation (GRE) tunnels, which
enables you to route or forward packets to a GRE tunnel. The
GRE tunnel connects two endpoints
in a point-to-point, logical link between the firewall and another
device. GRE tunnels are simple to use and are often the tunneling
protocol of choice for point-to-point connectivity, especially to
services in the cloud or to partner networks.