Securing Networks with Port Knocking: An Experimental Study on Ubuntu and Kali

Linux is an operating system developed with an open-source model. Various Linux distributions are available for free on the internet, ranging from Fedora, Ubuntu, Kali, Zorin, to Debian. Kali and Ubuntu are two examples of Linux distributions that are often used because of their user-friendly nature. In this paper, we will compare both distributions to see if there are any significant differences when faced with a Port Knocking simulation. Computer network security is crucial in maintaining the confidentiality of data and information on the server. Data and information should only be intended for authorized administrators and users who can access it through service ports. Therefore, the occurrence of Port Knocking can be dangerous for data owners. Through research conducted using the observation method and Port Knocking simulation, it was found that the Iptables configuration on the Ubuntu and Kali distributions has a slight difference. However, overall, the results are the same, which is that Iptables configuration can be done on LAN or WiFi, as long as all clients are on the same class, then the Iptables configuration can block client access to the server and vice versa.