config NETFILTER_XT_MATCH_PKNOCK
	tristate "Port knocking match support"
	depends on NETFILTER_XTABLES && CONNECTOR
	---help---
	pknock match implements so-called Port Knocking, a stealthy system
	for network authentication: client sends packets to selected, closed
	ports on target machine in a specific sequence. The target machine
	(which has pknock match rule set up) then decides whether to
	unblock or block (again) its protected port with listening
	service. This can be, for instance, used to avoid brute force attacks
	on ssh or ftp services.

	For more informations go to: http://portknocko.berlios.de/