Network Cards for OpenBSD

The official links to read are for the OpenBSD Intel Hardware Support Page, a bit at the top of the Networking Setup FAQ.
And all supported cards and the needed IRQ/port settings are found in the INSTALL.i386 document at the OpenBSD FTP site or on the OpenBSD CD you should buy anyway.

But my lowdown is: For 486 machines needing "ISA" network cards, it's 3COM if you can get them, an NE2000 clone if you can't.

Those with a Pentium to half-waste on a firewall have many more options with PCI cards. With PCI, most of the popular brands are supported well.

3COM network cards are the cadillac of the industry. They are one of the few companies even still making "ISA" bus network cards, and they still have the nerve to charge over twice what others do. But they're very good, and the OpenBSD support for them is good. They'll be recognized with almost any IRQ and memory setting. Two things:

  1. Use the config program on the floppy to make sure that Plug&Play is turned off
  2. It says any configuration will work in the docs, but I found you shouldn't mix IRQ 11 and memory 210. Two that definitely work:
    1. IRQ 11 and memory 300
    2. IRQ 10 and memory 210

3COM cards can be found for prices like $10 and $15 in "Used Computer" stores that carry parts. At those prices, they're the perfect choice.

CAUTION: Don't use two 3COM cards in the same firewall. It's unclear why (perhaps all 3COM cards have to share one buffer space because of the way the driver is written..?) but they will drastically slow down long file transfers through the firewall. Little speed loss will be noted on web pages that are a lot of <20K files, but if you download a megabyte or two, you will see up to 75% drop in speed compared to not going through the firewall. Some speed loss going through a firewall with a large transfer is to be expected (say 10% max), but 75% is just unacceptable.

NE2000 clone cards, by contrast, are the lowball end. They are also the only ISA cards you can get, new, besides 3COM.

I tried one common model, the "Startech 10MBps ISA", which actually required you to use jumpers to set the IRQ and memory. Once that was done right, they worked fine.

The other is from D-Link and I haven't tried it but a post on the Net said it worked. The OpenBSD site docs won't go into any of this at all. They don't like NE2000 and won't help you.

With NE2000 clones, only two combinations of IRQ and memory work:
IRQ 9, memory 240 -- also requires the "iomem" or "boot PROM" location set to d8000 (may appear as "d800" on your card or in the config software)
IRQ 10, memory 300

The latter will make the card "ne1", the former "ne0".

Some NE2000 clones, most notably the "AOpen" (really, Acer) model ALN-101, are the ones you want: OpenBSD spots them and uses the Plug&Play it claims not to have to configure them to either IRQ 3 or 4. These become ne3 or ne4 as device names.

The ALN-101 certainly appears to work fine. Depending on the firewall speed, you may see the odd message about "ring buffer overflow on ne3", but this does not mean any data has been lost, merely that a packet or two had to be retransmitted at some minor loss of performance. Best of all, the ALN-101 is still available, new, and for a lower price than is usually charged for a 3COM that is used.

One NE2000 clone NIC I found in used equipment stores says "AT/LANtic" on the chipset. These cards appear to be configurable using a program called "autonic" supplied on the OpenDOS bootable disk supplied.

There are some puzzling features to these models, perfect examples of why people who would rather spend money than time avoid NE2000 clones altogether: