fwknop stands for the "FireWall KNock OPerator", and implements an authorization scheme called Single Packet Authorization (SPA) ...
![[fwknop] Single Packet Authorization and Port Knocking](https://4.bp.blogspot.com/-wayp9EQvZ1M/Ut1Tfk-ngkI/AAAAAAAABnw/vUu4ukL8wnw/s72-c/fwknop_tutorial_network_diagram.png)
fwknop stands for the "FireWall KNock OPerator", and implements an authorization scheme called Single Packet Authorization (SPA) ...