🐧 Linux Essentials 🐧

📌 Introduction to Linux

• 🐧 UNIX, Linux, and Open Source
• 🖥️ What is Linux?
• 🏠 Linux Distributions
• 📂 Directory Structure of Linux
• 💾 Linux Installation
• 🌐 Remote Shell in Linux
• 🚦 Run Levels in Linux

🏗️ Linux Basic Commands

• 🗺️ All Basic Command in Linux
• 📁 Creating and Removing Directories and Files (mkdir, touch, rmdir, rm)
• 🔄 Copying, Moving, and Renaming Files and Directories
• 📜 Using the cat Command
• 🔗 Wildcards - Globbing Patterns
• ➡️ Pipes and Redirects
• 📦 Archiving and Compression
• 🗜️ Compression Tools (zip, gzip, bzip, tar, 7zip)
• 🎁 Archiving Tools
• ⚡ Linux Keyboard Shortcuts Cheat Sheet

✍️ Text Editors

• 📝 cat
• 🖊️ Nano, Vim, Gedit, and VS Code Text Editor in Linux
• 📝 vim

🎨 GRC (Generic Colouriser)

• 🎨 GRC (Generic Colouriser) in Linux

🔍 String Processing and Finding Files

• 🔝 head
• 🔚 tail
• 🔢 watch
• 📑 wc
• 📑 sort
• 🔍 grep
• ✂️ Grep cut
• 🔗 grep paste
• 📊 awk
• 🛠️ sed

🔎 Finding Files Commands:

• 🌳 tree
• 🔦 find
• ❓ which
• 📌 whereis

👥 Users, Groups, and Permissions

• 🏢 User & Group Management in Linux
• 📄 /etc/passwd File
• 🔐 /etc/shadow File
• 📂 /etc/group File
• 🔏 /etc/gshadow File
• 🐚 Shell in Linux
• ➕ Adding Users
• 🔄 Modifying User Accounts
• ❌ Deleting User Accounts
• 👥 Adding Groups
• 🛡️ Root Login
• 🔄 Sharing Superuser Privileges with others (su and sudo Commands)
• 🔀 sudo command Configuring
• 🔀 Linux sudo and sudoers File Configuration
• 🔏 Protect Grub Boot Loader by Password
• 🔑 File Permissions
• 🔐 Umask
• 🏷️ chown
• 🔄 chmod
• ⚙️ Setting Default Permissions
• 🏷️ SUID Bit
• 🏷️ GUID Bit
• 📌 Setting the Sticky Bit
• 🔐 Access Control Lists (ACL) in Linux
• 🔑 Reset Root Password

📦 Package Management

• 🖥️ Service Management in Linux
• 📦 RPM and dpkg Overview
• 📦 RPM and SRPM Packages
• 🛠️ RPM Packge Install, Upgrade and Remove
• 📦 Yum Command Overview
• 📦 dnf Command Overview
• 📦 apt Command Overview
• 📦 dpkg Command Overview

💾 File System & Disk Management

• 💿 Add a New Virtual Disk in VirtualBox
• 💿 Types of Disks
• 🛠️ Disk Partition Create, Delete, Formatting, Mount
• 📂 Mounting a File System
• 📊 Hard and Soft Quota Management
• 🔍 Logical Volume Manager (LVM)
• 🏗️ RAID Overview
  • ⚡ Uses of RAID
  • 📊 RAID Levels
  • 🖥️ RAID Levels

🌐 Network Configuration and Controlling Services

• 🌍 Network Configuration
• 🛠️ Network Tools
  • 🔄 ifconfig
  • 🔄 traceroute
  • 🔄 tracepath
  • 📡 netstat
  • 📡 ss
• 🌐 Network Clients
  • 🔐 ssh
  • 📦 scp
  • 📂 ftp
  • 🌍 wget
  • 🔄 rsync
• 📌 Checking the Status of Services
  • ✅ Service Status
  • ✅ Service Start
  • ✅ Service Stop
  • 🔄 Starting, Restarting, and Stopping Services

📊 Process Management, and Monitoring Tools

Here’s a more aligned and neat version of your list:

• 🔄 ps
• 🗺️ jobs
• ➡️ fg
• 🗜️ htop
• ⚡ kill

🦠 Installing & Configuring Antivirus Software

• 🔬 ClamAV Antivirus
• 🛡️ LMD (Linux Malware Detect)

🏰 Firewalls

• 🚧 iptables
• 🌐 firewalld
• 🔥 ufw` (Uncomplicated Firewall)

📊 Memory Management and System Performance Commands

• 📈 free
• 📈 vmstat
• 📊 iostat
• 🔎 lsof
• 🌐 kill

🐧 Debian 12 Setup Full Guide

• 🧰 Debian 12 Setup Guide 🐧

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🐧 Linux Server 🐧

🌐 Dynamic Host Configuration Protocol (DHCP) Server 🌐

• 📡 Dynamic IP
• 🚫 Exclusion IP
• 🔒 Reserved IP (Reservation)
• ✅ Allow and Deny List ❌
• 🔄 Different Pools for Known & Unknown Clients
• 🅽 Nginx Configuration

🌐 Domain Name System (DNS) Server 🛠️

• 🔠 DNS Records Types
• 🌍 DNS Client Tools (bind-utils)
  • 🛠️ dig
  • 🛠️ nslookup
  • 🛠️ host
• 🌐 DNS Server Types

  • 🔄 Non-Authoritative (Recursive) Nameserver

    • 🏪 Caching Nameserver
    • 📤 Forwarding Nameserver
    • ↩️ Reverse Zone Configuration

  • 🔐 Authoritative Nameservers

    • 👑 Primary (Master) Nameserver
    • 📦 Secondary (Slave) Nameserver

  • 🌍 Multiple Zone Configuration

    • 🖥️ nikhil.local
    • 🖥️ patidar.local
    • 🖥️ ai.local

🌐 Apache Web Server 🐧

• 🌐 Apache Web Server
• 🌐 Binding with IP Address in Apache
• 🌐 Binding with Ports in Apache
• 🌐 Binding with Domain Names in Apache
• 🌐 Binding with SSL and TLS in Apache
• 🌐 Binding Multiple Websites with SSL

🐧 PHP, MySQL and Wordpress 🌍

• 🐘 PHP
• 📝 MySQL
• 🌍 Wordpress
• 📂 Directory Listing on a Website
• 🏠 User Home Directories
• 🔗 WebDAV with Apache
• ⚙️ CGI Scripts (Common Gateway Interface)

📦 Joomla, Moodle, and PostgreSQL

• 🧩 Joomla
• 🎓 Moodle
• 🛢️ PostgreSQL

🌐 FTP (File Transfer Protocol) Server 📁

• 📦 Anonymous Access on FTP Server
• 🔐 FTP Client Usage
• 🏠 Access User Home Directory on FTP Server using vsftpd
• 👑 Allow Root Login on vsftpd (FTP Server)
• 👥 Login with Selected Users on vsftpd
• 📁 FTP Path Configuration in vsftpd
• 🔒 TLS Encryption on FTP

📂 NFS (Network File System) Server Configuration 📡

• 🔧 Network File System (NFS)

🗂️ SMB (Samba) Server 🧰

• 🖥️ SMB (Samba) Client Tools
• 🗃️ Samba Server Setup
• 🧑‍🤝‍🧑 Anonymous Samba Share
• 🗂️ Shared Common Directories With Samba
• 🔐 Share With Selected Users on Samba

🗂️ Trivial File Transfer Protocol (TFTP) Server 📤

• 📤 TFTP Server Setup
• 🖥️ TFTP Client Usage

🔐 SSH (Secure Shell) Server 🖧

• 🚀 SSH (Secure Shell) Server Setup
• 🔄 Change Default SSH Port
• 📍 Bind SSH to a Specific IP Address
• ⛔ Prevent Root Login via SSH
• ✅ Enable Root Login via SSH

🔐 SSH Public and Private Key

• 📁 SSH Public and Private Key Configuration
• 🛠️ SSH Keygen Usage and SSH Authentication Setup
• 🚫 Managing IP Allow and Deny in SSH
• 📋 Managing Access with hosts.allow and hosts.deny

🔐 SSH Client Tools

• 🖥️ SSH (Secure Shell)
• 📤 SCP (Secure Copy)
• 🔄 Rsync, WinSCP, PuTTygen

🛡️ Proxy Server 🌐

• 🚀 Squid Proxy Server Setup
• 🔒 Access Control List (ACL) in Squid
• 🧑‍💻 User Authentication Using Squid Proxy
• 🌐 Squid Transparent Proxy
• 🔐 SSL Bump with Squid Proxy

🖥️ Telnet Server 🔒

• 🛠️ Telnet Server Setup

💡 RDP Remote Desktop 🔒

• 🖥️ Rdesktop
• 🖥️ Xfreerdp
• 🖥️ Remmina
• 🖥️ NoMachine
• 🖥️ XRDP
• 🖥️ VNC

💡 Preboot eXecution Environment (PXE) Boot Server 💻

• 📘PXE Boot Server Setup Guide

🔐 LDAP (Lightweight Directory Access Protocol) Server 🛠️

• 🛠️ LDAP Server Setup Guide

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🅾️ Created by Nikhil Patidar

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📚 Reference & Attribution

🧾 Disclaimer:
This repository is a collection of Linux Server notes, built with reference to the sessions conducted by Mr. Sachin Verma Sir at Armour Infosec.
While the foundational knowledge and many core concepts are derived from the coaching content, I have also:

• 🛠️ Rewritten and structured the material in my own way
• 🧠 Added personal insights, practical examples, and formatting
• 📝 Included extra references and enhancements wherever needed 💡 The goal of this repo is to reinforce my own learning and to help the broader community — not for commercial purposes. 🙏 Special thanks to Mr. Sachin Verma Sir for their high-quality training and mentorship.

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🤝 Contributing

Feel free to contribute by adding similar content to this repository. Your help in improving the documents and making them more valuable is always appreciated.

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