The third idea -- Linux Firewall --

This system currently takes up less than 6MB on the CD Rom or Compact Flash and is based on a bare-bones version of FreeBSD, along with a web server, PHP and a few other utilities. The entire system configuration is stored in one single XML text file to keep things transparent.
We will use the the m0n0wall embedded firewall software package http://m0n0.ch/wall/

What have you need ?

• What Computer models ?
• Intel 486 family SX, DX, DX2 .....
• Intel Pentium family , MMX, II, III ....
  
• Intel Celeron family
  
• Hardware components:
• Base : CPU, RAM, Hrad Disk,Video Card, Floppy Disk & CDRom
• Two RJ45 Network Cards , or more
  
• Operating System:
• m0n0wall !!!!!!!!!!!
  

Example --->

We have a PC like this one :
Pentium MMX 133Mhz, 64 Mb Ram,Hard Disk 512 MB, Two Network Cards 10/100 Mbps, CDRom 12x, SVGA max 800x600, floppy disk, Monitor 14'', Keyboard and mouse.

• Installation m0n0wall ver. 1.23

Download the image from http://m0n0.ch/wall/download.php?file=generic-pc-1.23.img
Install your hard drive to another pc , for example connect the HD to the secondary ide interface.
On Linux system execute this command to write the image on your HD:

gunzip -c net45xx-xxx.img | dd of=/dev/hdX bs=16k
where /dev/hdx is the second ide interface, example "/dev/hdb/" or "/dev/sdb"
Now you have to install the hd on your computer ready for firewall services
Boot the computer :



Configure the lan network interface:

Select 1 to assign the network ports



Select 2 to assign the lan ip address




Connect to Web Admin interface , example http://192.168.66.99/




Now the system is ready to cofiguring firwall, followig this guide http://doc.m0n0.ch/quickstartpc/
for details