To protect SSH with Fail2Ban on CentOS 8, you can follow these steps: Install Fail2Ban by running the command sudo yum install fail2ban. Create a new Fail2Ban configuration file for SSH by running the command sudo nano /etc/fail2ban/jail.d/sshd.local. In the file, add the following configuration: [sshd] enabled = true port = ssh filter = sshd … Read more

Here’s how to enable and install the EPEL (Extra Packages for Enterprise Linux) repository on CentOS 8: Download the EPEL repository package by running the following command: sudo yum install epel-release Verify that the EPEL repository has been added by running the following command: yum repolist The EPEL repository should be listed among the enabled … Read more

To change the hostname on a CentOS 8 system using the command line, you can use the hostnamectl command. To set a new hostname, use the following command: sudo hostnamectl set-hostname newhostname Replace newhostname with the desired hostname for your system. To verify the hostname change, use the command: hostnamectl It will show the current … Read more

Here are the steps to upgrade Ubuntu 18.04 LTS to 20.04 LTS using the command line: Start by making sure your system is up-to-date by running the following commands: sudo apt update sudo apt upgrade Install the update-manager-core package, if it’s not already installed: sudo apt install update-manager-core Run the following command to check if … Read more

To add a new user account with admin access on Linux, use the useradd command followed by the -G option and the group name “sudo” or “admin”. For example: sudo useradd -m -G sudo newuser This will create a new user named “newuser” and add them to the “sudo” group, giving them admin access. Next, … Read more

SSH key-based authentication is a more secure way to log in to a remote server than using a password. It uses a pair of private and public keys to authenticate the user, rather than a password. In this way, only the user who has the private key can log in to the server. Here are … Read more

The product key for Windows 10/11 OEM (Original Equipment Manufacturer) is typically stored in the firmware of the device. You can use the following command on Linux to retrieve the product key: sudo cat /sys/firmware/acpi/tables/MSDM This command will print the product key in the output. You can also use the following command to extract the … Read more

To configure Nginx with Let’s Encrypt on CentOS 8 Install certbot: sudo yum install certbot-nginx Obtain a SSL certificate: sudo certbot –nginx Follow the prompts to enter your email address and agree to the terms of service Choose the domain name you want to generate the certificate for. The certbot will configure Nginx to use … Read more

There are several ways to count the number of processes running on a Linux system. Here are a few methods: Using the ps command: The ps command provides a snapshot of the current processes on the system. To count the number of running processes, you can use the following command: ps -e | wc -l … Read more

To update installed packages for security on CentOS 8/9, you can use the yum command as the root user or with sudo. Update the package index by running the command sudo yum update. This command will update all installed packages to the latest version. You can also update specific packages by providing the package name … Read more