A computer network security manager device connects to a first wireless router and then connects to a plurality of devices (e.g., a plurality of IoT devices). The computer network security manager device then performs device agnostic activation of the plurality of devices to enable the plurality of devices to perform respective functions of each device. The security manager device prevents the plurality of devices from connecting directly to the first wireless router and only allows other devices on the Internet to communicate with the plurality of devices according to specific firewall rules. In response to receiving an indication that the first wireless router to which the network security manager device is connected is out of service or no longer exists, the network security manager device prevents other devices on the Internet from being able to communicate with the plurality of devices.