fwknop Publisher's description
from Andreas Viklund.
fwknop stands for the "FireWall KNock OPerator",....
fwknop stands for the "FireWall KNock OPerator", and implements an authorization scheme called Single Packet Authorization (SPA). This method of authorization is based around a default-drop packet filter (fwknop supports both iptables on Linux systems and ipfw on FreeBSD and Mac OS X systems) and libpcap. SPA is essentially next generation port knocking (more on this below).
System Requirements:No special requirements.
Program Release Status: New Release
Program Install Support: Install and Uninstall