I think the recent issues were a result of the switch port that rawhide
box is attached to getting confused due to the bridging and it being a
very cheap switch (I have a Cisco, but it's loud and whiny and not in
this room with me). I'll keep an eye on it, but pretty reproducibly I
can just bounce the box on the power cycler to take it completely off
the network port, then power it back up and it seems to be ok.