Is the MR84 a repeater to a gateway MR? If so then what you describe is pretty much the same as my description. The PoE injector is powering the AP, but since the AP can’t get DHCP address from the PC (assuming it’s a reasonably standard config. on the PC) it will switch to repeater mode and try and find a gateway (or another repeater) and Mesh with it. The configuration in the Dashboard (Network-wide -> Configuration -> General -> Clients wired directly to Meraki APs) specifies which SSID the Ethernet port on the MR84 emulates.   Note that the MR84 needs two antennas, one connecting to the top two RF connectors, one connecting to the bottom two RF connectors, they should be the same antennas and covering the same area since all the ports are dual band and the radios are both 4x4:4. ... View more