Paranoid Penguin - Building a Transparent Firewall with Linux, Part II

Use commodity to hardware to build a transparent firewall.

But, this is as far as I can take you this month. Next time, I'll begin showing how to configure networking, bridging and, of course, iptables on our transparent firewall.

If you can't wait until then, see the OpenWrt home page for more information, or if you're really adventurous, search the Web for other tutorials on creating transparent firewalls with OpenWrt. But, if I say so myself, we're off to a good start!

Mick Bauer ( is Network Security Architect for one of the US's largest banks. He is the author of the O'Reilly book Linux Server Security, 2nd edition (formerly called Building Secure Servers With Linux), an occasional presenter at information security conferences and composer of the “Network Engineering Polka”.



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Transparent firewall

keeper.oregon's picture

Glad to see someone else is trying to tackle this issue. Over the winter break/holidays, I resdesigned my home/remote-office/spouses-business networks from three seperate layer-3 firewalls to a single layer-3 network. I was hoping to utilize the fifth port on two of the wireless routers. I have been trying to get my Cisco LinkSys WRT320N to keep broadcast/multi-cast media traffic local. I will look into the OpenWRT to attempt layer-2 firewall the WRT320N.