Tag: Ubuntu

Ubuntu is a Linux distribution (distro) built on Debian architecture and infrastructure. It is installed on everything from servers to mobile devices. Catch up on some reading about all things Ubuntu-related below.

Harden SSH on Ubuntu 24.04: Disable Root, Use Key Auth, Restrict IPs

Harden SSH on Ubuntu 24.04

Learn how to harden SSH on Ubuntu 24.04. Disable root login, enforce SSH key authentication, and restrict IP access for maximum protection. Table of Contents 🔈Introduction Secure Shell (SSH) is the backbone of remote system management, but an exposed or misconfigured SSH service is a prime target for attackers. Ubuntu 24.04, as a modern Linux […]

Splunk Email Security Risk: How to Fix allowedDomainList Warning in alert_actions.conf

Splunk allowedDomainList configuration

Learn how to fix the Splunk allowedDomainList security warning in alert_actions.conf. Prevent unauthorized alert emails and protect sensitive data by configuring domain restrictions correctly. Table of Contents 🔈Introduction Splunk administrators often encounter a critical security warning: ⚠️ Found an empty value for ‘allowedDomainList’ in the alert_actions.conf configuration file. This alert points to a significant security misconfiguration […]

How to Monitor SSH Logins Using Auditd and Logwatch

Monitor SSH logins using Auditd and Logwatch

Learn how to monitor SSH logins using Auditd and Logwatch on Linux. This step-by-step guide covers setup, configuration, log analysis, and reporting to enhance server security. Table of Contents 🔈Introduction Secure Shell (SSH) is one of the most widely used methods for remote server administration. Because it provides a gateway into critical infrastructure, monitoring SSH […]

Configure a Firewall using UFW (Ubuntu) and Firewalld (RHEL)

Configure a firewall using UFW and Firewalld

Learn how to configure a Linux firewall using UFW on Ubuntu and Firewalld on RHEL. Step-by-step CLI examples, best practices, and comparison tables included. Table of Contents 🔈Introduction Securing your Linux server is a critical step in system administration. One of the foundational layers of server security is the firewall — a system that controls […]

Fixing the Apache Error: Invalid Command ‘Header’

Apache error Invalid command Header

Learn how to fix the Apache error “Invalid command ‘Header’” when configuring a web server. Step-by-step guide with CLI commands, configuration examples, and troubleshooting tips to get your Apache server running smoothly. Table of Contents 🔈Introduction When running a web server, nothing is more frustrating than Apache failing to start because of a cryptic configuration […]

Install XRDP on Ubuntu 24.04 for Remote Desktop Access

Install XRDP on Ubuntu 24.04

Learn how to install and configure XRDP on Ubuntu 24.04 LTS to enable secure remote desktop access from Windows, macOS, or Linux. Step‑by‑step setup with firewall rules, troubleshooting tips and performance/security best practices. Table of Contents 🔈Introduction Remote desktop access to Linux machines is essential for administrators, remote workers, developers, or anyone needing GUI access […]

Upgrade to PHP 8.4 on Ubuntu 22.04 | 24.04

Upgrade PHP 8.4 Ubuntu 22.04 24.04

Upgrade to PHP 8.4 on Ubuntu 22.04 or 24.04 with this complete, step‑by‑step guide. Includes commands, configuration, Apache & Nginx setup, troubleshooting, and best practices to ensure a smooth migration. Table of Contents 🔈Introduction Modern PHP releases bring faster execution, new features, and better security. PHP 8.4, though still developing in mid‑2025, is increasingly adopted by developers. If you’re […]

How to Enable Fail2Ban to Block Repeated Failed Login Attempts on Linux

Enable Fail2Ban to block failed login attempts

Learn how to configure Fail2Ban to block repeated failed login attempts on Linux. Step-by-step guide with commands, configuration examples, and security tips for SSH and other services. Table of Contents 🔈Introduction In today’s threat landscape, brute-force attacks are a common way attackers attempt to gain unauthorized access to Linux servers. A simple and effective defense […]

Upgrade Ubuntu‑22.04 to 24.04 in 5 Steps

Upgrade Ubuntu 22.04 to 24.04 LTS

Step‑by‑step guide: how to safely upgrade Ubuntu 22.04 LTS (“Jammy”) to Ubuntu 24.04 LTS (“Noble”) in 5 essential steps—backup, update, configure the upgrader, run the release upgrade, and verify clean‑up. Table of Contents 🔈Introduction Upgrading from Ubuntu 22.04 LTS (“Jammy Jellyfish”) to Ubuntu 24.04 LTS (“Noble Numbat”) is a major step forward: newer kernel, updated toolchains, long‑term support until […]

Understanding Regular Expressions: A Beginner’s Guide

Understanding Regular Expressions

Learn the basics of Regular Expressions with this beginner’s guide. Discover how to use regex for text searching, validation, and data extraction in Linux, programming, and more. Table of Contents 🔈Introduction Regular Expressions (regex) are an essential tool for anyone working with text processing or data extraction in Linux, programming, or even everyday tasks. While […]