Creating a Firewall Using EigerStein: Preparing the PC

Preparing the PC

Prior to installing EigerStein, the PC must be readied. This includes verifying system requirements, removing unnecessary components, and configuring network adapters. Once the PC is ready, you can then begin working on the EigerStein software.

Verify System Requirements

486 DX or higher. (A 486 SX will work, but requires additional work which is not covered here.)
12 Mb RAM minimum (16 Mb recommended)
3.5" floppy disk drive (two if you want lots of features) capable of reading 1.44 Mb disks
Keyboard and monitor (during the install)

Removing Unnecessary Components

If there is a hard disk drive in the PC, it can be removed. You will not need it. Also, any special adapter cards such as IO adapters (unless they control the floppy disk drive), extra printer port cards, sound cards etc. can be removed. If an item isn't required, I would recommend removing it. Theres no reason to keep it there complicating the system, and generating more heat when it offers no advantage.

Configuring the Network Adapters

You will need two network adapters, the PC, a DOS boot disk, the network card drivers, the Network Information Sheet (Appendix C), pencil, and two stickers, 1/4" by 1". Mark one sticker Internal, the other External. Before we actually talk about configuring the cards, lets consider which cards to purchase. There are many NICs which are compatible with Linux (check out the Hardware HOWTO in the Resources section at the end of this document). My experience has been that cards which are compatible with the NE2000 adapter seem to work the best. Of course, if a manufacturer has their own Linux driver software and support, thats a great option, too. I have never had trouble with configuring NE2000 adapters, and I have had occasional success with 3Com 3C509B adapters, so I will cover these.

Laptop Installation

See Appendix E - Laptop-Specific Issues, in addition to this section, for hints on preparing a laptop as a firewall.

NE2000 Adapters

Boot the PC in DOS, then load your NIC configuration software from the driver disk Configure the first card using the following guidelines (consult the documentation for your adapter for more details):

Duplex - If you have this option, set the card to whatever your hub, switch, or other connection can support.
Plug and Play - Shut it off.
Port or IO address: 300 (may also be listed as 0x300, or 0x0300) - Write this number down in block 25 of the Network Information Sheet.
IRQ or Interrupt: 5 - Write this number down in block 26 of the Network Information Sheet.
Notes: Place the "Internal" sticker on the back of this card so you can see it from behind the PC. Write down the MAC address of this card on the Network Information Sheet in block 24.

Some NIC configuration applications are not able to configure two cards residing in the PC at the same time. One application known not to work is that shipped with older Kingston ISA adapters (even though it says you can using 'QSTART /MULTIPLE'). If this is the case, you may have to remove the NIC you just configured. Using the same driver software, configure the second adapter with the following specifications:

Duplex - If you have this option, set the card to whatever your hub, switch, or other connection can support.
Plug and Play - Shut it off.
Port or IO address: 280 (may also be listed as 0x280, or 0x0280) - Write this number down in block 21 of the Network Information Sheet.
IRQ or Interrupt: 3 - Write this number down in block 22 of the Network Information Sheet.
Notes: Place the "External" sticker on the back of this card so you can see it from behind the PC. Write down the MAC address of this card on the Network Information Sheet in block 20.

3Com 3C509B Adapters

Configuring 3Com adapters is a bit more difficult than NE2000-compatibles. The reason is that it's not always clear which adapter will be activated first. The first adapter activated will be eth0 (the external NIC), however. When using ISA cards, I have read that the card with the lower MAC address is activated first (though I have not verified this). When using PCI adapters, the order of activation is based upon which slot each card resides in. I suggest not labeling the adapters, or putting the case back on until you have gone through configuring your firewall settings, and can successfully ping to both sides. Additionally, you need not write down the adapters' I/O or IRQ settings on the Network Information Sheet (unless you want to for the sake of completeness of documentation) as these are not explicitly passed to the NIC driver.

Duplex - If you have this option, set the card to whatever your hub, switch, or other connection can support.
Plug and Play - Shut it off.
Port or IO address: 300 (may also be listed as 0x300)
IRQ or Interrupt: 5

The 3C5X9CFG.EXE configuration utility allows you to configure more than one card at a time. As such, installing one card at a time is not necessary when using 3Com NICs. Simply move over to the Select menu, and select the next adapter in the list to configure. Once you do this, make the following changes to the second adapter.:

Duplex - If you have this option, set the card to whatever your hub, switch, or other connection can support.
Plug and Play - Shut it off.
Port or IO address: 280 (may also be listed as 0x280)
IRQ or Interrupt: 3

All Adapters

If you are configuring PCI NICs, write down the slot numbers for each NIC in blocks 23 and 27 of the Network Information Sheet. This may be helpful in figuring out which NIC is which when they are initialized, as some drivers will initialize NICs in lower PCI slots before initializing those in higher PCI slots. As such, if you configured only one NIC at a time, place both NICs back in the PC, inserting the External NIC in a lower slot number than the Internal NIC.

Some NIC configuration programs require that the PC be rebooted after changing the Plug and Play setting in order to continue the configuration. If this is the case, reboot the PC after changing the Plug and Play settings. Once you are finished configuring the NICs, shut the PC down, and set it off to the side. We will come back to it once we have an EigerStein disk. If you are using 3Com NICs, don't forget to do a ping test, and then label the adapters once you are finished with the Configuring EigerStein section.

Contents

Linux Primer

Preparing the Disk