Introduction Learn how to safely remove old kernels on CentOS , RHEL , and Fedora to free up space and improve system performance. Step-by-step guide with best practices for maintaining your Linux system. As you continue to update and upgrade your Linux system, particularly on distributions like CentOS, RHEL, and Fedora, old kernels can accumulate over time. While these kernels are essential for booting your system, having too many can clutter your boot menu and consume valuable disk space. This guide will walk you through the process of safely removing old kernels from your system without risking stability, ensuring that your Linux machine runs smoothly and efficiently. Why Should You Remove Old Kernels? The Problem with Accumulating Kernels Linux kernels are the core of the operating system, responsible for managing hardware and system processes. Every time you update your system, a new kernel may be installed, but the old ones aren't automatically removed. This can lead to seve...

Introduction In this tutorial, we will explore how to install and configure AIDE (Advanced Intrusion Detection Environment) on CentOS. AIDE is a powerful tool designed for monitoring changes to files on the system, helping you detect unauthorized access and modifications.  Ideal for system administrators and security professionals, this guide will provide step-by-step instructions to ensure a successful setup of AIDE on your CentOS system. By the end of this tutorial, you will have a robust intrusion detection system in place, capable of providing detailed reports about the integrity of your files and system security. What does Aide mean AIDE is one of the most popular tools for monitoring the server changes in a LINUX based system.  It call as Advanced Intrusion Detection Environment. Install AIDE on Centos $ sudo yum install aide Check AIDE Version on your system $ sudo aide -v Configure AIDE $ sudo cp /etc/aide.conf /etc/aide.conf_BK Add lines not check /tmp ...

In this tutorial, Things to Do After Fresh Installation Fedora 30. Let do it! TO DO 1. Update your Fedora Always keep your system updated to the latest version of packages. $ sudo dnf update 2. Change the hostname $ sudo hostnamectl status # view current hostname $ sudo hostnamectl set-hostname --static "VivoS15" # set up new hostname 3. DNF tweak edit /etc/dnf/dnf.conf file $ sudo cp /etc/dnf/dnf.conf /etc/dnf/dnf.conf_ORIG [huupv@localhost ~]$ cat /etc/dnf/dnf.conf [main] gpgcheck=1 installonly_limit=3 clean_requirements_on_remove=True fastestmirror=true deltarpm=true 4. Install RPM fusion repository $ sudo dnf update --refresh $ sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm $ sudo dnf install https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm 5. Player and codecs $ sudo dnf install youtube-dl vlc $ sudo dnf in...

Introduction Welcome to our detailed guide on how to check for open and closed SSH ports. In today's networked world, maintaining secure server connections is critical. Secure Shell (SSH) is a network protocol that provides administrators with a secure way to access a remote computer.  However, ensuring that your SSH ports are configured correctly is essential to prevent unauthorized access and breaches.  This tutorial will provide you with step-by-step instructions on using various tools to determine the status of SSH ports on your system. Whether you're a seasoned system administrator or a novice user, these skills are fundamental to managing and securing your network connections. In this tutorial, How to checks all ports if they are closed or open and if the current ssh version? Using nmap command. Read man nmap page. First, you need to install nmap . For ubuntu $ sudo apt-get install nmap For centos $ sudo yum install nmap For example, checks for open/closed ports...

Introduction Security is a top priority in any system, and email is no exception. Zimbra FOSS offers a robust open-source email solution, and setting up two-factor authentication (2FA) is a crucial step to enhance security. This article will guide you through the process of setting up 2FA on Zimbra FOSS in a detailed and easy-to-understand manner, ensuring your email accounts are better protected against potential threats. In today’s digital landscape, securing your email accounts is paramount. Zimbra FOSS (Free and Open Source Software) provides a powerful email platform, widely adopted for its flexibility and reliability. To strengthen its security, integrating two-factor authentication (2FA) is a must. This guide will walk you through the step-by-step process of enabling Zimbra FOSS 2FA, ensuring that your email platform is robust against unauthorized access. Why Use Two-Factor Authentication with Zimbra FOSS? Two-factor authentication adds an extra layer of security by requiring u...

In this tutorial, How to configure Leverage browser caching for nginx. What does Leverage browser caching mean? Page load times can be significantly improved by asking visitors to save and reuse the files included in your website. Reduces page load times for repeat visitors Particularly effective on websites where users regularly re-visit the same areas of the website Benefit-cost ratio: high Access needed You should add that inside of an existing server block. For example, I will add that inside server block /etc/nginx/sites-enabled/default file. server {     listen       80;     server_name  localhost;     location / {         root   /usr/share/nginx/html;         index  index.html index.htm;     }         location ~* \.(js|css|png|jpg|jpeg|gif|ico)$ { ...

Introduction In the world of cybersecurity, reverse proxies are essential for a variety of applications, from load balancing to security testing. One such tool that has caught the attention of professionals is Modlishka . In this article, we’ll explore the features, benefits, and best practices for using Modlishka while maintaining ethical standards in cybersecurity. What is Modlishka? Modlishka is a cutting-edge reverse proxy tool designed to facilitate advanced security testing and penetration testing. Unlike traditional reverse proxies, Modlishka can seamlessly forward web requests while maintaining full control over data transmitted between the client and the target server. This ability makes it especially useful for testing login credentials, bypassing security filters, and conducting social engineering attacks in a controlled and ethical environment. Key Features of Modlishka Impersonation Capabilities : Modlishka can act as a middleman between the target and the user, allowing a...

Introduction Mastering tips and tricks while working with Zimbra can help you maximize the platform's email features. This article compiles useful tips and tricks in a PDF format, making it easy for you to access and apply them in your daily work. Let's explore and enhance your productivity with Zimbra through the practical suggestions shared in this article. Zimbra Collaboration Suite is a powerful, open-source email and collaboration platform designed for businesses and organizations. It offers robust email, calendar, contact management, and file-sharing capabilities, making it a favorite among IT professionals. This guide delves into sharing tips and tricks with Zimbra, providing a step-by-step exploration of essential techniques and tools to boost productivity and collaboration. Understanding Zimbra’s Sharing Features What is Zimbra Sharing? Zimbra Sharing allows users to collaborate by granting access to their email folders, calendars, tasks, or address books. With customi...

Introduction Discover the world of Linux bin bash shell in this comprehensive guide. Learn from basic to advanced examples, understand shell scripting, and explore frequently asked questions. The Linux bin bash shell is an essential component of the Linux operating system, providing users with a command-line interface to interact with the system. Whether you are a beginner looking to understand the basics or an advanced user seeking to refine your scripting skills, this guide offers a detailed exploration of the bin bash shell. What is the Linux Bin Bash Shell? Understanding the Shell The shell in Linux is a command-line interpreter that executes user commands. The term "bash" stands for Bourne Again Shell, an enhanced version of the original Unix shell created by Steve Bourne. It is the most popular shell in Linux, with its executable located at /bin/bash . Why Use Bash? Versatility : Bash is widely used for its simplicity and power. Scripting : Automate tasks through shell...