I hooked up the ethernet cable to the computer from the ultra 5, then put the ethernet devices up on both sides. Assigned an IP address for the ultra 5 using:
ifconfig hme0 192.168.1.102
Then, did the same thing on the host side:
ifconfig nfo0 192.168.1.102
After that, it didn't work, so I took the ultra 5 into the room with the router, hooked it up to the router, and put up hme0, and all worked well. So I don't know why the computer to computer thing isn't working.