Old Skool DOS based networks with switch

[Asha'man X]

Get hold of Realtek 8029's, they have DOS drivers on a stiffy, or should be easy to find on the net. Most computer rooms will have those cards laying around somewhere, they were a staple about 10 years ago. Otherwise 8139's may do it.

As some of the other posters have said though, look at VM's, they are a life saver. Makes backup a breeze too.