Arch Linux global navigation bar Home Packages Forums Wiki Bugs AUR Download #archnavbar Port Knocking From ArchWiki Jump to: navigation , search start content Port knocking is a stealth method to externally open ports that, by default, the firewall keeps closed. It works by requiring connection attempts to a series of predefined closed ports. When the correct sequence of port "knocks" (connection attempts) is received, the firewall opens certain port(s) to allow a connection. The benefit is that, for a regular port scan, it may appear as the service of the port is just not available. This article shows how to use port knocking with either a daemon or with iptables only. 1 Introduction 2 Port Knocking with a daemon helper 3 Port Knocking with iptables only 4 Port knocking script 5 See also Introduction iptables is a pre-requisite to install and configure be...