...already authenticated with your router and still connecting to it, not a new device. But the monitoring box connects downstream from the wireless router, th

...already authenticated with your router and still connecting to it, not a new device. But the monitoring box connects downstream from the wireless router, though: ___ ___ \|/ \|/ | | ISP --> my Wi-Fi router --> mystery box --> wired devices ___ \|/ | wireless devices The mystery box acts as a Layer 2 bridge for wired devices, but it must sniff wireless devices from the air. The FAQ that came with it strongly suggests that it sniffs all the wireless networks it can see, not just mine. Edit: to improve the ASCII art diagram