code: def add_gre_port(self, name, remote_ip,
                       local_ip=None, key=None, ofport=None):
          
          self.add_tunnel_port(name, 'gre', remote_ip,
                               local_ip=local_ip, key=key, ofport=ofport)
docs: Creates a GRE tunnel port.
  
          See the description of ``add_tunnel_port()``.