Just installed my second M5 system in a house. All works well. While setting up port forwarding I notice that my modem reports a different MAC address for the M5 base unit it is hard wired to. 

The modem identifies the connected M5 unit as **:**:**:**:11:11 whereas the Android TP-LINK app reports **:**:**:**:11:10

Is this a known feature, or are there two separate hardware addresses for a reason?