There is provided a network node for detecting a communication device (stealth device) in a local network and identifying a type of the detected communication device. According to the embodiments of the present invention, the network node 200 detects a search message sent out by a stealth device, and sends a response message to the stealth device as if the network node 200 were a target node to be searched for. The network node 200 then receives a request message from the stealth device, and extracts, from the request message, identification information (e.g., a User-Agent header) that corresponds to a type of the stealth device. The identifying unit 208, which may be located inside or outside the network node 200, identifies the type of the stealth device based on the extracted identification information.