The firewall can terminate a GRE tunnel to connect two
endpoints in a point-to-point, logical link.
Palo Alto Networks next-generation firewalls
can now terminate GRE tunnels; you can 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 often the
tunneling protocol of choice for point-to-point connectivity, especially
to services in the cloud or to partner networks.
GRE tunnel when you want to direct packets that are destined for
an IP address to take a certain point-to-point path, for example
to a cloud-based proxy or to a partner network. The packets travel
in the GRE tunnel to the cloud service while on their way to the
destination address. Thus the cloud service can enforce its services
or policies on the packets.
The following figure is an example
of a GRE tunnel connecting the firewall across the internet to a