Introduction In this article we will see why we are getting “user is not in the sudoers file” error and what we can do about it. But before we start, let’s learn some theory. I will be using CentOS 7 for demo. What is sudo? sudo is a command that allows you to run other
Introduction In this post we will learn how to enable SSH server on your Ubuntu. What is SSH? SSH (Secure Shell) is a network protocol which supports encryption. It is mainly used for a remote secure configuration and management. It is common to use SSH protocol for a remote Linux administration. If we want to
Introduction In this article we will see how it is possible to log SSH or telnet session output to a file. I usually use this method for saving the configuration of remote network devices like routers or switches, but it might be useful in any other situations when you need to save all session output
Introduction In this post we will learn how to find files and directories in Linux using command-line utility called find. This utility can search for files based on a great number of parameters and therefore it makes it very powerful and useful tool. Another good thing about find utility is that it allows to execute various
Introduction In this post you will learn about curl command in Linux and then have a look at some common curl examples. What is curl? Curl is a command-line utility used for sending and getting data using URLs. curl supports various protocols, including HTTP, HTTPS, FTP, SCP, SFTP, TFTP, LDAP, TELNET, POP3, SMTP and others. It
Introduction In this short Ansible tutorial we will go through the installation process of Ansible and its basic features. Ansible is an automation tool which allows us to manage remote servers without installing any agents on those remote machines. Only the control machine needs to have it installed. By “remote servers” I mean not only Linux/Windows
Introduction This guide will show you how you can perform a network speed test using two Linux machines. It will show you the actual network bandwidth between two points in your network. We will connect a Linux machine at each point in you network and generate traffic between them. We can use simple laptops, desktops
Introduction In this tutorial we will learn how to configure iptables which is a built-in Linux firewall. I will use Ubuntu 18.04 for demo, but you can use any other Linux distro. Before we get into actual configuration we will learn some theory behind iptables. iptables allows us to filter packets based on IP addresses,
Introduction In this guide we will create a systemd service and make it automatically start on a boot. We have already seen how we can make commands execute on a boot using cron scheduler in this post. Creating systemd service file is an alternative way of doing this, and since systemd is becoming more and
What is grep ? Grep stands for Global Regular Expression Print. Grep utility is usually used to find lines in a file/files containing particular strings and substrings. Grep comes preinstalled on any modern Linux distribution, so we can start using it without having to install anything. Before we start looking at usage examples of grep
