You can, but you will need a third NIC in the machine to make it clean. http://bridge.sourceforge.net/ This site has a lot of reference material in order to actually pull it off. Basically, you place the 5 PC's on their own network with your existing Firewall with the new third NIC plugged into it. The Firewall forwards (bridges) any traffic sent to your public IP computers. The internal bridging logic of Linux once configured will route those packets to the third interface transparently. The only effective change here is that now you can control the channel between those computers and the internet, hence allowing for those machines to be firewall protected. >Is there any possibility to make my Linux box work as a firewall, not >only for the NAT-ed machines, but also for >these 5 computers that have real IP's? _______________________________________________ LARTC mailing list / LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/