I just stumbled upon two RB411s that are behaving strangely:
If you power it via the power jack, the Ethernet port sends out PoE! It can actually power another RB.
(Unfortunately, if you plug it into a non-PoE jack, it seems to kill power to the 411. That’s how I found these.)
There are no patch wires soldered between the jack and the Ethernet pins, on either side of the board. Could it be a failed diode? Has anyone else seen this happen?