This is a joke, but a real service like this could be neat. For example, it listens on all ports and returns a "null" response based on the typical service of

This is a joke, but a real service like this could be neat. For example, it listens on all ports and returns a "null" response based on the typical service of that port. Not-very-well-thought-out-examples: http - Always returns 404. https - Always returns 404. ipp - Returns whatever IPP says for "printer not found" or equivalent. lpd - Takes data, does nothing with it. dns - Always returns NXDOMAIN. ident - Always returns nobody:nogroup telnet - Accepts any username/password/credentials, returns "This account is not available" and immediately exits. ssh - Accepts any username/password/credentials, returns "This account is not available" and immediately exits. smtp - Accepts message, doesn't do anything with it. pop3/imap - Accepts any login, always has 0 messages. irc - Accepts any nick, PRIVMSG or other commands, commands don't actually do anything. Returns null list of channels and users when queried. vnc - ? rdp - ? Etc.