I am a fan of wired ethernet connections.
This may or may not have to do with my interest in ancient/obsolete/old workstations and their operating systems.
You can forget to use a wifi connection with your old Sun Ultra 1 but you can probably use wired ethernet.
However, sometimes you cannot run an ethernet cable.
Enter the VAP11G.
You can power the VAP11G from a USB port but just forget about it (remember, old workstations = no USB). Just use a 5V adapter and you are ready to go,
I was lucky as my unit can be configured with its webpage. So, just connect to the VAP11G (192.168.254.254 or just use wifi as you will probably want to do this with a somewhat recent personal computer) and configure it to connect to your Wi-Fi network.
Done that, plug the VAP11G in an old swith and let your DHCP server work its magic.