IP Networking over USB

Greetings. I'm just starting to delve into cluster environments, and now have a usage scenario in which it would make more sense to ask this question. Thus far, I have my Master Control Node and a Slave Node built to spec with what I can afford. I would like to avoid having to go out and get more networking equipment and jump straight to something a bit exotic. Either I missed this item, or it wasn't covered in the handbook. A Google search also yielded nothing.

I would like to link USB<->USB and tunnel TCP & UDP between the channels. I have just enough ports on the Master to accommodate two (2) slaves with this setup.

Does anyone know if this is possible for FreeBSD?

If you have a proper managed switch you can use vlan(4) interfaces to separate the traffic. Physically you'd have one interface and one cable but logically you'll have two or more interfaces and networks.