Apparently the hub in the server room has given up the ghost. The lights still flash, but I couldn’t get to the big wide world from either of the computers in that room.
When I went directly from the webserver to the wall outlet, the big wide world was back.
Second Son doesn’t know it yet (he’s in Cali), but he’s getting me a new hub for Christmas.
(Actually, he’s not–that’s just in case he’s reading this tonight.)