There was a big thunderstorm here this morning and I think it affected the network somewhat. I turned on the Windows box (what? You think I leave that thing running all night? With all the garbage Windows spews forth on the network?) and after it finishes booting, it can't see the network.
The hub shows a connection. I remove the termination from the 10Base2 connection and half the network goes down like it should, so the hub is fine. Okay, restart Windows.
I check monnet, and I see some wierd stuff—the Windows box is sending out Ethernet packets with the broadcast address as the source! That's not right.
I shutdown Windows and powercycle the machine.
Now it's okay.
Man, Windows is just sooooooo wierd.