“Here’s how I turned an unused PC into a packet-filtering
firewall using a package called floppyfw . The firewall boots off a
single floppy, runs completely in RAM, and uses ipchains for the
filter rules. It also does IP masquerading, port forwarding, and
can log to a remote host using syslog. All this in a machine with
as little as 8 MB of RAM and no hard drive!“
“floppyfw’s author, Thomas Lundquist, describes it as a Linux
“screening router with firewall capabilities”. It boots a Linux
kernel and comes with a minimal set of tools to get the job done.
If you think about it, that’s actually a feature. If a bad guy were
to get into your firewall machine somehow, there won’t be much for
him to use against you. And since we’re running completely on a RAM
disk, a simple reboot from the floppy will restore the system to
its original state.”
“As with many Linux projects, floppyfw has a do-it-yourself
aspect. But I’ll show you where I found a set of
almost-ready-to-run filter rules, so you can quickly set up your
own firewall.”