ubuntu

Port knocking is a method of protecting your services behind a firewall until connection attempts are made to a specific sequence of ports in a certain amount of time. The firewall rules are then modified to allow access to the service and the user can connect as normal. In this article, we will discuss how to implement port knocking to add an extra layer of protection to your SSH daemon in order to dissuade attackers.

SSH is a way of connecting to a remote server securely. It includes a number of mechanisms to perform this task in a safe way. However, the protocol assumes that the computer that you are connecting from is secure. In this guide, we will instruct you on how to set up one time passwords as an option for connecting to your server from an insecure location. We will do this by configuring the OTPW utility on an Ubuntu 14.04 machine.