config BR2_COMPILE_KNOCK tristate default n depends BR2_PACKAGE_KNOCK || BR2_PACKAGE_KNOCKD config BR2_PACKAGE_KNOCK prompt "knock............................. A port-knocking client" tristate default m if CONFIG_DEVEL select BR2_COMPILE_KNOCK help It listens to all traffic on an ethernet (or PPP) interface, looking for special "knock" sequences of port-hits. A client makes these port-hits by sending a TCP (or UDP) packet to a port on the server. This port need not be open -- since knockd listens at the link-layer level, it sees all traffic even if it's destined for a closed port. When the server detects a specific sequence of port-hits, it runs a command defined in its configuration file. This can be used to open up holes in a firewall for quick access. http://www.zeroflux.org/cgi-bin/cvstrac/knock/wiki config BR2_PACKAGE_KNOCKD prompt "knockd............................ A port-knocking server" tristate default m if CONFIG_DEVEL select BR2_COMPILE_KNOCK help It listens to all traffic on an ethernet (or PPP) interface, looking for special "knock" sequences of port-hits. A client makes these port-hits by sending a TCP (or UDP) packet to a port on the server. This port need not be open -- since knockd listens at the link-layer level, it sees all traffic even if it's destined for a closed port. When the server detects a specific sequence of port-hits, it runs a command defined in its configuration file. This can be used to open up holes in a firewall for quick access. http://www.zeroflux.org/cgi-bin/cvstrac/knock/wiki