The Sun Lunchbox computers don’t take 10baseT ethernet natively. Instead, you need to get an Ethernet AUI adaptor. You can buy these new or used at a variety of price points. I chose to buy a new one from Blackbox. Setup of IP address and default route was reasonably easy and completely manual as things were back then. For anyone that has used an AUI adaptor you probably remember the goofy connector that “sort of" locks onto the computer, then provides a 10baseT (or whatever) on the other end. The “lock” doesn’t work, never worked, and is just a pain to use. But, thats what we are working with here. Same mess with my recently acquired SGI Indigo.
The real struggle came when it came time to setup DNS. In this area of Sun, the focus was on Yellow Pages/NIS. This was an over-complicated name resolution system that just kinda sucked. It’s an example of a community of software engineers trying to solve a problem in a too complicated way, and it eventually failed. Anyway…
My experience with workstations really started when I worked at NASA. I recall at the time that Sun was focused on NIS and NASA, and as I recall many Universities had no interest in a proprietary name resolution system. As a result, these organizations refused to support NIS lookups and demanded DNS name resolution. Sun, not wanting to break with their decided upon standard at the time, supplied an alternate library archive that the customer could patch libc with to provide DNS name resolution. This allowed all the programs that used the libc library (which was all of them) to use DNS for name lookups rather than the brain-dead NIS system. This was “kind-of” listening to your customer in 1991.
I ultimately found the instructions on how to do this in a usenet thread where the University of Colorado Boulder (in my own back yard) described a procedure of opening the libc library, deleting a few functions, then adding replacement functions of the same name from the alternate archive not dependent on NIS. After replacing those and adding the required /etc/resolv.conf file. DNS name lookup worked like it works today.
The procedure to patch libc in SunOS 4.1