. . "n SWAN 100c, if the machine field of the same packet does not match one of the pre-approved identifiers, the result is a partial match and the network address of the packet is considered an uncertain address by firewall 185c1.FIGS. 3A, 3B and 3C are a truth table, a block diagram and a flowchart, respectively, illustrating the operation of another embodiment of intelligent firewall 185c1." . . . . .