We have an RB1100 at a clients premises and tried to plug the lan port of a UBNT POE supply from a RocketM5 into port 12 with the result being an instant total freeze of the RB1100. We had to power cycle the Mikrotik to bring it back on line and the POE injector seems to have suffered as well. It is repeatable and happens on multiple ports.

The router is in a live environment so further testing is difficult.

I originally thought it was the POE but a second one (both brand new) did the same so I added an RB433AH in line with the data cable and it worked fine.

Any ideas?

Cheers,
Dan