You can use Blue Iris as an NVR plus any ONVIF compliant camera. This is what I do, with the cameras on their own VLAN so they can’t phone home. It’s entirely

You can use Blue Iris as an NVR plus any ONVIF compliant camera. This is what I do, with the cameras on their own VLAN so they can’t phone home. It’s entirely possible to do what you want.