The IT people never did figure out exactly what happened. They just wanted me off the network so they could begin rebooting everything. Several state agencies were offline for a couple of hours.
I think it had something to do with me having set up the Mac as a web server to enable me to run Apache, PHP, mySQL, and Joomla on it. Somehow in making the network settings adjustments for the Novell network, I apparently did something that caused the Macintosh to start acting as a gateway server for the entire network.
Luckily, I guess, the Internet wasn’t quite as mission-critical then as it is today.