Stealth-Mode

A controversial method of increasing security is to conceal the router by not conforming to standards and rejecting TCP and UDP requests, but by ignoring them (stealth mode) . This is controversial because the failure to answer can also betray the existence of a device. If there truly is no device present, the previous router will respond to the relevant packets with 'undeliverable' as it is unable to deliver them. However, if the previous router no longer responds with a corresponding rejection, the packet is 'deliverable' and, regardless of the recipient's subsequent behavior, is most certainly present. It is not possible to simulate the behavior of the previous router without keeping your device offline or switching it off (and thus making it unreachable for the services you yourself request).