Installing OpenBSD to make a firewall

To make your own home firewall, you need:

An old PC:

  1. 486/25.

  2. (A 386/33 with 16MB seemed to run an OK firewall, but did not get a prolonged test.)
  3. 16MB RAM

  4. 12MB works, but takes 10 minutes to boot up. Indeed, 8MB actually appears to work, but only after we (soon) post detailed special install instructions and floppy. And it would need other special adjustments. Please, just find more RAM.
  5. 100MB hard drive.

  6. OK, an 80 if you skip the manuals and rely on the web.
  7. TWO Ethernet network cards

  8. And not all brands are supported, so read:
    Brand recommendations and individual install instructions.
  9. To go through a careful install procedure no tougher than assembling a barbeque.

  10. And for most of us, quite a bit easier. And quicker.
There is a very good and complete OpenBSD install procedure at the OpenBSD site. Certainly more informative than anything you will get here.

The instructions below are given in the spirit of barbeque assembly. Even if you have never touched Unix before and cannot type a Unix command, go keystroke-by-keystroke through the following with most common "old junk" office PC hardware, and you will likely get a working system without looking at the real manuals. If you have trouble, try the above links.
Before software installation, two preparations:

  1. Set up the hardware.

  2. The two network cards need to be plugged in, and they need to be set to different IRQs and whatnot.
    Brand recommendations and individual install instructions.
  3. Make an OpenBSD boot floppy

  4. Download the boot floppy image,
    If you have Windows 9x, also download "rawrite.exe" ,
    If you have Windows NT, instead download "ntrw.exe",
    If you have a Mac, umm...stay tuned. There's software out there somewhere...
    If you have UNIX - look up the "dd" program with man.
    If you have Windows 2000 or XP...the NTRW program should work.
    The its just one command:
    For Win98: rawrite and hit "enter", and follow the prompts. (Source is "floppy38.fs" and destination is "a".)
    For NT, the one command is: ntrw floppy38.fs a:

Put the floppy in the drive, and get the network cable ready. This is what happens next, on-screen, and from you at the keyboard:

Power up! While it's booting, read The OpenBSD Install Script

After OpenBSD is installed:

Onward to the first boot and "bsdwall" package install