Networking needs the ethernet mac adaptor.

I do have a crossover cable that could be used to share onto the Linux box, and I've been trying to fix the phone line into mission control to put the wireless router (with 4 RJ45 ports).

Sneakernet is the easiest way. In my mind the compacts were designed for the days when computers like these were usually standalone and networking / appletalk was thought of as an addon.