Requirements:

• 1 - Soekris NET4801
• 1 - PfSense Embedded Image
• 1 - CF Reader
• 1 - Serial Cable for the soekris
• 1 - CF Card 256 MB

The Steps I took:

1. Backup your old Soekris / Monowall configuration xml file
2. Buy a new CF card so we can keep the old configuration sane so it's plug and play "back to working" incase pfsense doesn't work
3. Plug your cf reader into one of your linux boxes, and do this with the image

   
   # zcat pfSense-1.0.1-Embedded.img.gz | dd of=/dev/sda bs=16k
   

   where /dev/sda is your cf card as seen by the OS. If you are not using a linux box, you can check out the howto's available at the following URL

4. Remove the CF card by unplugging the usb cable then the cf card.
5. Shutdown the Soekris, Remove the case and remove current CF Card, place aside
6. Place the new image card inside and then plug in your cables.
7. Connect serial cable to your linux box and set term to 9600 8N1. I use minicom.
8. Start up minicom on your linux box.
9. Plug in the Soekris
10. If it doesn't boot, you may have to set the bios to have the CF Card as primary.
    This note is thanks to the pfsense digest

    
    To do this enter the bios by pressing ctrl-p on boot and:
    
    set flash=primary
    
    reboot
    

11. Watch as it boots to make sure nothing is funky
12. Now you should see the configuration interface on your pfsense box, through minicom (the serial connection)
13. Setup the LAN and WAN interfaces
14. Connect to the LAN interface via a laptop, and configure the web interface
15. Remove laptop, plug into your switch, and you're good to go.

I like pfsense. It's got a lot more options than m0n0wall, and while it's a little slower on my soekris 4801, it's still a great addition to my network :)