How all this got started

I have MediaOne cable net service. The "cable modem" takes in coax on one side and spits out 10BaseT Ethernet on the other. I wanted to share the network access between a big pile of machines already hooked together by Ethernet. Unfortunately, the MediaOne Ethernet cable must be directly connected to a computer---there's only one IP address routed, and the "cable modem" only wants to talk to the single Ethernet MAC address registered with MediaOne.

Routing on a budget

The obvious solution was to put a proxy (or NAT) host between my internal net and the MediaOne connection. Because I've been a Linux weenie for ages, I thought this would be a good chance to try out IP Masquerading (plenty of other pages, or heck, Google search). Since the routing machine didn't need to do much, I figured a small hard drive would be enough until I discovered the Linux Router Project---they manage to fit a kernel and a ramdisk image with basic network software on a single floppy. Machines running the LRP software don't need a hard disk.

Choosing the hardware

I already had a few machines lying around that would work for this purpose, but none of them were completely satisfactory, and I wanted a new toy.

Requirements

General principles

I have rules of thumb for choosing hardware, especially when building machines from parts. These are ones relevant to this buy.

Quality parts and manufacturers

I feel comfortable spending slightly more on products from reputable manufacturers I've dealt with before. No, I've never had a problem with the Biostar motherboards I own, but I feel a lot more comfortable with Tyan or ASUS.

Commodity parts when possible

If you buy a totally-integrated box from a vertically integrated vendor, there will be approximately seven other people in the world who have the same configuration and the same problems as you. I had a Compaq Deskpro XL 590 once (PCI and EISA slots), and it was a huge pain to get Linux running on it.

Cheap

I have better things to do with my toy budget than to spend twice as much money on something for a tiny improvement in some unimportant aspect.

Public prices

I despise having to phone or fax or submit a web form to get a price quote. That makes me feel like the price will depend on how big the salesperson thinks my wallet is. Either that, or I feel like the vendor is trying to avoid direct price competition. That's stupid; customers usually are willing to spend more money for better service or other intangibles in a transaction. In niche markets, sophisticated buyers already understand that prices are somewhat negotiable and affected by the prospect of future volume business.

Specific requirements

Small and quiet

The boxes I had were all mid-towers. I wanted a box that could sit on a shelf in a closet, or next to a desk. (Andrew Wilson points out that I'm not doing a good job of addressing the "quiet" issue later. I'll see what I can do.)

I'm interested in hearing about affordable rackmount solutions.

Runs Linux

Duh. Supported by the LRP bootdisks out of the box would be a bonus.

Two Ethernets (three better)

At some point I may want to run Internet-accessible services from my home network. I prefer to keep processes like sendmail and imapd away from machines that I care about. Three Ethernets would give me the MediaOne connection, an enclave of workstations, and a separate network for untrustworthy service machines.

Reproducible

I probably could have found some machines used or at computer shows. I didn't want a system I couldn't clone or get parts for quickly.

Useful as network appliance

It would be nice if it was useful in other network appliance situations; for example, as a modem-based router, or as a print server.

Can operate with no writable media

I like having all state on the machine stored on write-protected media. If you think someone broke into the system, just reboot.

Cool

There's some hard-to-define "wow" factor I was looking for. I think brutally low-tech, cheap systems are cooler than they look.

Jay Carlson -- nop@nop.com

Last updated Feb 15, 1999; prices and availability last checked Feb 14, 1999.