The Null Device
Posts matching tags 'port knocking'
2004/2/6
Port knocking is a way of letting a computer accept connections to a port (such as ssh) without leaving it open (and vulnerable to attackers). The port is typically firewalled off from the internet; however, if the firewall receives a sequence of connection attempts to a specific sequence of ports, which is kept secret, it relaxes the firewall rules enough to allow the IP address in question to connect to the protected port. (via Slashdot)