Linux

“Defense in depth” (DiD) is a cyber security strategy that uses multiple security products and practices to safeguard an organization’s network, web properties, and resources. It is sometimes used interchangeably with the term “layered security” because it depends on security solutions at multiple control layers — physical, technical, and administrative — to prevent attackers from… Read more: What is Defense In Depth?

Krasue infects telecom firms in Thailand using techniques for staying under the radar. Stealthy and multifunctional Linux malware that has been infecting telecommunications companies went largely unnoticed for two years until being documented for the first time by researchers on Thursday. Researchers from security firm Group-IB have named the remote access trojan “Krasue,” after a… Read more: Stealthy Linux rootkit found in the wild after going undetected for 2 years

Systemd is used by Debian, Arch, Fedora, Ubuntu, and many downstream Linux distros. Windows’ infamous “Blue Screen of Death” is a bit of a punchline. People have made a hobby of spotting them out in the wild, and in some circles, they remain a byword for the supposed flakiness and instability of PCs. To this day, networked… Read more: New systemd update will bring Windows’ infamous Blue Screen of Death to Linux

The rsh (remote shell) program was a tool for remotely running a command on a remote computer. It has since been superseded by ssh. Everyone who still has rsh enabled is encouraged to disable it for important security reasons immediately. The rsh tool was introduced in BSD Unix in the 1980s. It was an important tool at the time but suffered several… Read more: RSH – the legacy remote shell tool

Authentication is the process of verifying identity. It requires using passwords, hardware tokens, or several other methods. In cyber security, authentication is verifying someone’s or something’s identity. Authentication usually occurs by checking a password, a hardware token, or some other information proving identity. Just as an airline worker checks a passport or an identification card… Read more: What is authentication?

Properly implemented DDoS mitigation is what keeps websites online during an attack. Explore the process of DDoS mitigation and the essential characteristics to look for in a mitigation service. What is DDoS mitigation? DDoS mitigation protects a targeted server or network from a distributed denial-of-service (DDoS) attack. A targeted victim can mitigate the incoming threat using… Read more: What is DDoS mitigation?

Single sign-on (SSO) is a vital cloud security technology that reduces all user application logins to one login for greater security and convenience. What is single sign-on (SSO)? Single sign-on (SSO) is a technology that combines several different application login screens into one. With SSO, users only have to enter their login credentials (username, password,… Read more: What is SSO? | How single sign-on works

Command line interpreter definition & common command line interfaces A command line interpreter is any program that allows one to enter commands and then execute those commands to the operating system. It’s an interpreter of commands. Unlike a program that has a graphical user interface (GUI) like buttons and menus that a mouse controls, a command line interpreter… Read more: What Is a Command Line Interpreter?

Virtual machines (VMs) are computers that run inside of other computers using a process known as virtualization. What is a virtual machine? A virtual machine (VM) is a software-based computer within another computer’s operating system, often used for testing, backing up data, or running SaaS applications. To grasp how VMs work, it’s essential to understand… Read more: What is a virtual machine?

“The power of sudo is strong with this one!” Sudo is a command-line utility for Unix and Unix-based operating systems such as Linux and macOS. The utility provides an efficient way to temporarily grant users or user groups privileged access to system resources to run commands they cannot run under their regular accounts. Users can… Read more: The power of Sudo – Linux

Host command is a minimal and easy-to-use the command line interface, or CLI utility for performing DNS lookups which translate domain names to IP addresses and vice versa. It can also be used to list and verify various types of DNS records such as NS and MX, test and validate ISP DNS server and Internet… Read more: Useful ‘host’ Command Examples for Querying DNS Lookups

nslookup is a command-line administrative tool for testing and troubleshooting DNS servers (Domain Name Server). It is used to query specific DNS resource records (RR) as well. Most operating systems come with a built-in nslookup feature. This article demonstrates the widely used nslookup command in detail. Nslookup can be run in two modes: Interactive and… Read more: 8 Linux Nslookup Commands to Troubleshoot DNS (Domain Name Server)

In this article, you will learn how to install the dig command and nslookup command on Linux. These commands are used for network troubleshooting and gathering information about domain names. Dig, short for Domain Information Gopher, is a DNS lookup utility used for probing DNS servers and troubleshooting problems associated with DNS servers. Due to… Read more: How to Install and Use dig and nslookup Commands in Linux

In our previous article, we have explained nslookup command examples and usage, which is a networking command-line tool used for querying and getting information of DNS (Domain Name System). Here, in this article, we come up with another command line tool called dig, which is much similar to the Linux nslookup tool. We will see… Read more: 10 Linux Dig (Domain Information Groper) Commands to Query DNS

Sometimes your Linux distribution doesn’t detect your laptop’s Bluetooth hardware. Or perhaps you want to add a USB Bluetooth dongle to a desktop computer. Either way, here’s how to get Bluetooth working. Bluetooth is named after a 10th-century Danish king, Harald Bluetooth. He was known as the unifying king. By encouraging communication between the many… Read more: How to Set Up Bluetooth on Linux

Feel like starting over? This tutorial will show you how to cleanly and safely reboot or shut down your Linux or macOS computer from the command line. We’re Going Down Sometimes you just have to go for the reboot or the total shutdown. If you’re working on a GUI-less server or you’re on an SSH… Read more: How to Reboot or Shut Down Linux Using the Command Line

The Linux File System – Explained

Free and paid tools and services for Windows and Linux The best patch management software makes managing software updates across your computing devices and IT networks simple and easy. With new software vulnerabilities and exploits appearing daily, installing Windows and application security patches as soon as they’re released is vital. Unfortunately, that’s not always easy.… Read more: Best patch management software of 2023

Kali Linux is an open-source, Debian-based Linux distribution geared towards various information security tasks, such as Penetration Testing, Security Research, Computer Forensics, and Reverse Engineering. This niche prefers that distro; these tools could be manually installed on other Linux Distros, maybe even Windows ports. However, Kali and Parrot Linux are the more popular Linux Distros… Read more: Best Open Source Penetration Testing Tools

If you want to cause chaos in a Linux environment, put this in the ~/.bash_aliasis file… PURE EVIL. Caution, do not try this at home kids!

When we refer to access control systems, we’re talking about providing access to restricted areas of the enterprise. But familiarity and correctly utilizing access control systems to protect proprietary information are two completely different levels of understanding. For example, who gets access to what? What are the rules? How is access tracked? The user must first be… Read more: Types Of Access Control Systems

Client-side and server-side are web development terms that describe where application code runs. Web developers will also refer to this distinction as the frontend vs. the backend, although client-side/server-side and frontend/backend aren’t quite the same. In a serverless architecture, the serverless vendor hosts and assigns resources to all server-side processes, and the processes scale up as… Read more: What does client-side and server-side mean? | Client-Side vs. Server-Side

Digital transformation, regardless of whether a private venture or a large organization, has empowered companies to produce information at every touchpoint. Irrespective of the organization, each organization requires a database to sort out and store its fundamental data. To provide such a facility, the database management system software is to the rescue. A database can be referred… Read more: Top 15 best Databases for web applications to Use in 2022

Cryptography studies secure communications techniques that allow only the sender and intended recipient of a message to view its contents. The term is derived from the Greek word “kryptos”, which means hidden. It is closely associated with encryption, which is scrambling ordinary text into what’s known as ciphertext and then back again upon arrival. In addition, cryptography… Read more: Cryptography Definition

You don’t remember individual mobile numbers. Instead, you go to your contacts app and call it by their names. The contacts app allows people to input everyday words without having to keep track of the individual mole number. This is the exact same thing DNS does for the internet. Domain Name System Computers address each… Read more: DNS Explained

Do you have a Windows 11 computer or device and don’t know how to access the UEFI or BIOS? Are there any issues with your PC that you think can be repaired from there? Whether you need to enter UEFI/BIOS to troubleshoot your computer or adjust settings to improve its performance, in this tutorial, we… Read more: How to enter the UEFI/BIOS from Windows 11

CONTENTS If you are a casual computer user, you may have heard about the BIOS, UEFI BIOS, BIOS failures, or Dual BIOS motherboards, but you might be wondering what these terms mean. What is a BIOS except for a weird-sounding acronym? What does BIOS do? Is it that important for the operation of a computer?… Read more: What is BIOS? What does BIOS mean?

When administering MySQL database servers, one of the most common tasks you’ll have to do is to get familiar with the environment. This involves tasks such as listing databases that reside on the server, displaying the tables of a particular database, or getting information about user accounts and their privileges. This tutorial explains how to show all databases in… Read more: How to Show a List of All Databases in MySQL

MySQL is the most popular open-source relational database management system. MySQL server allows us to create numerous users and databases and grant appropriate privileges so that the users can access and manage databases. This tutorial explains using the command line to create and manage MySQL or MariaDB databases and users. Before you begin Before starting… Read more: How to Manage MySQL Databases and Users from the Command Line

Typically when you run a command in the terminal, you have to wait until the command finishes before you can enter another one. This is called running the command in the foreground or foreground process. When a process runs in the foreground, it occupies your shell, and you can interact with it using the input… Read more: How to Run Linux Commands in Background

MySQL is the most popular open-source relational database management system. This tutorial explains how to create MySQL or MariaDB databases through the command line. Before you begin We are assuming that you already have MySQL or MariaDB server installed on your system. All commands are executed as an administrative user (the minimum privilege required to create a new… Read more: How to Create and Select MySQL Databases

MySQL is the most popular open-source relational database management system. This tutorial describes how to delete (or drop) a MySQL or MariaDB database through the command line. Before you begin All commands are executed as an administrative user (the minimum privilege required to delete a database is DROP) or with a root account. To access the MySQL console type… Read more: How to Delete a MySQL Database on Linux via Command Line

MySQL is the most popular open-source relational database management system. MySQL server allows us to create numerous user accounts and grant appropriate privileges so that the users can access and manage databases. This tutorial describes how to create MySQL user accounts and grant privileges. Before you Begin We assume you already have MySQL or MariaDB… Read more: How to Create MySQL Users Accounts and Grant Privileges

MySQL allows you to create multiple user accounts and grant appropriate privileges so that the users can connect and manage databases. If the user account is no longer needed, it is a good idea to either remove the user privileges or to completely delete the user account. This tutorial explains how to delete MySQL/MariaDB user accounts. DROP… Read more: How to Delete MySQL Users Accounts

In this tutorial, we will show you how to change MySQL user passwords. The instructions should work with any modern Linux distribution such as Ubuntu 18.04 and CentOS 7. Prerequisites Depending on the MySQL or MariaDB server version you are running on your system, you will need to use different commands to change the user… Read more: How to Change MySQL User Password

Have you forgotten your MySQL root password? Don’t worry, it happens to all of us. In this article, we will show you how to reset the MySQL root password from the command line. Identify the Server Version Depending on the MySQL or MariaDB server version you are running on your system, you will need to… Read more: How to Reset the MySQL Root Password

Have you ever needed to get a list of all users in your MySQL server? There are commands to show databases and tables, but there is no MySQL show users command. This tutorial explains how to list all user accounts in a MySQL database server through the command line. We’ll also show you how the find out… Read more: How to Show/List Users in MySQL

GDU Disk Usage Analyzer is a graphical disk usage analyzer for GNOME. It was part of gnome-utils but was split off for GNOME 3.4. It was originally named Baobab after the Adansonia tree. The software gives the user a menu-driven, graphical representation of what is on a disk drive. GDU is inspired by godu, dua, ncdu, and df and is intended primarily for… Read more: How to Install and Use Gdu Disk Usage Analyzer on Ubuntu 20.04

Contents: Option 1: Display the Size of a Directory Using the du Command Option 2: Get Size of Directory in Linux Using tree Command Option 3: Find the Size of a Linux Directory Using ncdu Command Introduction Many users run Linux from the command line. However, the command line – sometimes known as the terminal… Read more: How to Get the Size of a Directory in Linux

Introduction How much space do I have free on my Linux drive? Managing disk space on a Linux server is an important task. For example, package manager applications notify you of how much disk space will be required for an installation. For that information to be meaningful, you should know how much space your system has available.… Read more: How to Check Disk Space in Linux

Prerequisites Step 1 — Installing Apache and Updating the Firewall How To Find your Server’s Public IP Address Step 2 — Installing MySQL Step 3 — Installing PHP Step 4 — Creating a Virtual Host for your Website A Note About DirectoryIndex on Apache Step 5 — Testing PHP Processing on your Web Server Step… Read more: How To Install Linux, Apache, MySQL, PHP (LAMP) stack on Ubuntu 20.04

Introduction Sudo is SuperUser DO and is used to access restricted files and operations. By default, Linux restricts access to certain system parts, preventing sensitive files from being compromised. The sudo command temporarily elevates privileges allowing users to complete sensitive tasks without logging in as the root user. In this tutorial, learn how to use the sudo command in Linux with… Read more: How to Use the sudo Command in Linux

Log files are an essential part of Linux system administration and monitoring. But log files also quickly grow and take up a lot of storage space. The good news is that a tool called Logrotate in Linux lets you manage log files effectively. In this tutorial, you’ll learn how to configure Logrotate so you can manage and… Read more: How To Manage Logfiles with Logrotate in Linux

ping (Packet Internet Gropper) The Ping command allows a user to ping another network IP address. Ping command sends ICMP ECHO_REQUEST packets to other hosts, and this command can help determine the connectivity to the remote host. This is similar to playing “Marco Polo” in a body of water. Simple ping command syntax is ping… Read more: Common Network tools – ping, telnet, netstat and arp

I’ll compare the Norton 360 Deluxe plan, their second most expensive, to Bitdefender’s most expensive Total Security plan. Why do you ask? Because they both claim to offer the same level of protection and supplemental features, by and large, they’re almost identical packages…or so I thought… ? Bitdefender vs. Norton: Malware protection: ? Now, starting… Read more: Norton 360 Deluxe vs Bitdefender Total Security | Best antivirus for PC

plipconfig – fine-tune PLIP device parameters SYNOPSIS plipconfig interfaceplipconfig interface [nibble NN] [trigger NN] [unit NN] DESCRIPTION Plipconfig is used to (hopefully) improve PLIP performance by changing the default timing parameters used by the PLIP protocol. Results are dependent on the parallel port hardware, cable, and the CPU speed of each machine on each end of… Read more: PLIPCONFIG

DISCLAIMER I’m not a certified financial planner/advisor nor a certified financial analyst nor an economist nor a CPA nor an accountant or a lawyer. I’m not a finance professional through formal education. I am just a hacker. I am unsure of my reboot scripts at this moment, or if the new XMR / Monero miner, MoneroOcean.stream’s new… Read more: Nightly Reboot – Linux Cronjob Example

Ssh is a secure protocol used to manage remote systems like Linux, BSD, UNIX, network devices event windows operating systems. The traffic between systems is encrypted. Ssh uses asymmetric keys in order to encrypt and make traffic invisible to the others who reside between systems in the network. The encryption power comes from key bit… Read more: How To Generate 4096-bit Secure ssh Key with ssh-keygen

I recently read that SSH keys provide a secure way of logging into a Linux and Unix-based server. How do I set up SSH keys on a Linux or Unix-based system? In SSH for Linux/Unix, how do I set up public-key authentication? This page explains a public key and shows you how to set up… Read more: How To Set up SSH Keys on a Linux / Unix System

Table of Contents The Objective The purpose of this post is to explain with an example how ansible initiates the reboot and waits for the reboot to complete. In some cases, we want our remote nodes to be rebooted or restarted. For example, Take Patching as an example. As part of quarterly patching, we upgrade… Read more: Ansible: yum update, reboot system, and wait_for reboot to complete

There are several ways to check the availability of a file in Linux. The “test” command in bash scripting is one of the critical approaches to checking a file’s existence. The focus of this guide is to discuss the presence of a file in your system through bash scripting: How to check file existence using… Read more: How to check if a File exists in bash

Indeed to reboot the VM or bare metal Linux machine/server using Ansible and wait for it to come back but it does not work with the playbook as described here. How to reboot the Linux server with Ansible? How do I reboot and wait for the reboot to complete in the Ansible playbook for multiple… Read more: Ansible reboot Linux machine or server with playbooks

If you’re troubleshooting a service that you know is running normally, the next step is to ensure it’s listening on the correct network port. The netstat command shows the services listening to ports on a Linux server and the details of any connections currently made to them. During basic network daemon troubleshooting, the connection details… Read more: How to display listening ports using the netstat from the command line

The vi and vim editors allow you to copy text from your file into temporary buffers for use in other places in the file during your current vi work session. Each buffer acts like temporary memory, or, as some programs call it, a “clipboard” where you can temporarily store information. The simplest case would be… Read more: How to use buffers to copy and paste lines in VI/VIM

I recently added some extra repositories with the Mysterium network and received this error when I reloaded the apt package database: To fix this, I found to execute the following commands in the terminal: sudo apt-key adv –keyserver keyserver.ubuntu.com –recv-keys <PUBKEY> sudo apt-key adv –keyserver keyserver.ubuntu.com –recv-keys ECCB6A56B22C536D Then Update the apt cache: ALTERNATE METHOD:… Read more: How do I fix the GPG error “NO_PUBKEY”?

All the Linux distributions are either derivatives of GNU/Linux ( OS made up of Linux Kernel developed by Linus Torvalds and GNU software repository) or derived from other Linux derivatives. This post will review the top 12 most popular Linux distributions based on the usage statistics and market share. DistroWatch has been the most reliable source… Read more: Linux Download: Top 12 Free Linux Distributions for Desktop and Servers

CentOS 8 Early EOL in 2021 and CentOS Stream The CentOS 8 life cycle has been cut short with the news of its EOL in December 2021. RHEL revealed it would be shifting focus from CentOS Linux to CentOS Stream. Most CentOS users who have updated their systems to the latest version have already expressed their concerns. While CentOS… Read more: CentOS 8 Early EOL in 2021 and CentOS Stream

What is the Simple Mail Transfer Protocol (SMTP)? The Simple Mail Transfer Protocol (SMTP) is a technical standard for transmitting electronic mail (email) over a network. Like other networking protocols, SMTP allows computers and servers to exchange data regardless of their underlying hardware or software. Just as a standardized form of addressing an envelope allows the… Read more: (no title)

Here, we will compare these two protocols’ main characteristics, and we will look at TCP Protocol (Transmission Control Protocol) and UDP Protocol (User Datagram Protocol). This comparison is very important and, generally, a question asked in Network Engineering, Cyber Security, or Infrastructure interviews. It also is important for students and security certification tets and is a simple… Read more: TCP vs UDP

What is SSH? SSH, or Secure Shell or Secure Socket Shell, is a network protocol that gives users, particularly system administrators, a secure way to access a computer over an unsecured network. SSH also refers to the suite of utilities that implement the SSH protocol. Secure Shell provides strong password authentication, public key authentication, and encrypted data communications between two… Read more: What is SSH?

Proxy chains are open source software for Linux systems and come pre-installed with Kali Linux, the tool redirects TCP connections through proxies like TOR, SOCKS, and HTTP (S), allowing us to chain proxy servers. With proxy chains, we can hide the IP address of the source traffic and evade IDS and firewalls. We can use… Read more: How To Use Proxy chains with Kali Linux

Web servers use HTTP (Hypertext Transfer Protocol) and other protocols to respond to client requests made over the Internet. The main job of a web server is to display website content by storing, processing, and delivering web pages to users. In addition to HTTP, web servers also support SMTP (Simple Mail Transfer Protocol) and FTP… Read more: Definition – Web Server

Introduction Ubuntu 20.04 (codenamed Focal Fossa) was released on April 23, 2020. It is a Long-Term Support (LTS) release, which will receive support and updates until April 2025. This guide will help install a fresh copy of Ubuntu 20.04 LTS on your computer. Prerequisites System requirements (recommended): 2 GHz dual-core processor 4GB memory 25GB available disk… Read more: How to Install Ubuntu 20.04 LTS Desktop (Focal Fossa)

Open-source is a term used to describe computer programs that have source code that’s available to study, modify, and share. Open-source software can be used for any purpose, studied and changed, and shared with others. This has encouraged a spirit of openness and sharing that has resulted in a welcoming and inclusive community. And with… Read more: What is Open-Source

Setting up cron jobs in Unix, Solaris & Linux Cron is a Unix, Solaris, Linux utility that allows tasks to be automatically run in the background at regular intervals by the cron daemon.  Cron meaning – There is no definitive explanation, but the most accepted answer is reportedly from Ken Thompson ( author of Unix cron… Read more: Crontab – Quick Reference

How do you remove a password from a .key file using OpenSSL. You will be prompted for your original password, so enter that first then the new key will be written afterwards. Note you could have the -in and -out parameters be the same but if you get it wrong you could mess up your… Read more: Remove Key Password with OpenSSL

Using the passwd command, you can change a user’s password and settings related to password expiry. There are two possible ways to achieve this, as described in detail, below. Using passwd Command To force a user to change his/her password, first of all the password must have expired and to cause a user’s password to expire, you… Read more: How to Force User to Change Password at Next Login in Linux

In this tutorial, you will learn: The default Ubuntu firewall is ufw, with is short for “uncomplicated firewall.” Ufw is a frontend for the typical Linux iptables commands, but it is developed in such a way that basic firewall tasks can be performed without the knowledge of iptables. Additionally, ufw can be managed from a graphical interface, gufw.… Read more: How to enable/disable the firewall on Ubuntu 20.04 LTS

SSH is the most secure means of connecting to Linux servers remotely. And one of the common errors encountered while using SSH is the “ssh: connect to host port 22: No route to host”. In this short article, we will show how to troubleshoot and fix this error. Here is a screenshot of the error we… Read more: How to Fix “No route to host” SSH Error in Linux

How does it work? Netplan reads network configurations from /etc/netplan/*.yaml, written by administrators, installers, cloud image instantiations, or other OS deployments. During early boot, Netplan generates backend-specific configuration files in /run to hand off control of devices to a particular networking daemon. Netplan currently works with these supported renderers. Software requirements and conventions used Category Requirements, Conventions or Software… Read more: How to manually set up a Static or DHCP NIC in Ubuntu 20.04

Package Description The NET-3 networking toolkit Quick Install Instructions of net-tools on Ubuntu Server. It’s Super Easy! Simply Copy (CTL-C) to copy the command and paste (CTL-V) it into your command line terminal using the built-in APT package manager. You will need admin rights to install this like almost anything when you use apt or apt-get (yum but that’s… Read more: How To Install “net-tools” Package on Ubuntu / Debian

What if you had to memorize the IP address of every website that you wanted to visit? I bet you’d go crazy in no time! This is where DNS jumps into the scene. The Domain Name System has revolutionized the Internet. In this article, I’m going to discuss what a DNS actually is and how it works.… Read more: What is DNS, and How Does DNS Work? (Domain Name Server Fundamentals)

The ‘/etc/fstab’ file is one of the important configuration file used by Linux machines which specify the devices and partitions available and where/how to use these partitions. This file will be created/updated during the system installation. You need to modify or maintain it in the way you need to use the devices/partitions. In Linux each… Read more: Fstab File (/etc/fstab) options and manual configuration

The simple stuff Depending on whether you want to add ~/opt/bin at the end (to be searched after all other directories, in case there is a program by the same name in multiple directories) or at the beginning (to be searched before all other directories). You can add multiple entries at the same time. PATH=$PATH:~/opt/bin:~/opt/node/bin or variations on the… Read more: How to correctly add a path to PATH?

The shell can be defined as a command interpreter within an operating system like Linux/GNU or Unix. It is a program that runs other programs. The shell facilitates every computer user as an interface to the Unix/GNU Linux system. Hence, the user can execute different tools/utilities or commands with a few input data. The shell… Read more: Linux/Uniux Shells