Care of webopedia.com: 100BASE-TX: two pairs of high-quality twisted-pair wires 100BASE-T4: four pairs of normal-quality twisted-pair wires 100BASE-FX: fiber optic cables As for getting it to work, you can specify the media with ifconfig. I don't remember the exact syntax off hand but I think it goes something like: ifconfig -media 10baseT/UTP I ran into this with a FreeBSD machine where the 3.x worked but 4.x didn't like my network card. Turns out it defaults to the AUI port (which shows up the in the boot messages... duh) but it had me scratching my head for a while. Hope this helps, Charlie