@williamtries @dosgameclub I've had surprisingly good times with that once I found the right kind of card; my 486 Aptiva presently has a 3Com Etherlink III in ISA. The drivers for it are still available and easy to locate for both DOS and Windows 3.11, and it is not difficult to set up mTCP in a pure-DOS environment to access LAN and/or internet (for example, to FTP things to/from the computer): https://www.brutman.com/mTCP/
(gah, had the wrong link earlier)