It’s an ethernet wire that’s going to be exiting my house and running to a camera in a publicly accessible space. An attacker could disconnect the camera, connect a laptop and access my network. How could I protect against that (other than a physical lock)? I basically want to lock down that cable to the point where nothing works on it unless it’s the intended camera. If this was wireless, I’d just use MAC filtering, but I don’t see an equivalent for wired connections.
Most extreme way I can think of…. Using a good router like PFSense or OpnSense you make a VLAN for the camera only. Create a firewall rule allowing only that camera to access the other network via specific needed ports only. Even if they spoofed the MAC they would also need to route traffic through the associated ports as well and would take a while for anyone mother then an expert to figure out wtf is going on.