🛰️ linux-system-management-3

Project 3 of 3 in the Linux System Management series
Focus: SSH service validation, PXE basics, DNS and name resolution

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📌 Objectives

• Verify and harden SSH server configuration
• Understand PXE boot role and discovery process
• Investigate DNS resolution settings and tools
• Use host, dig, and nslookup to resolve names and test DNS behavior

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📁 Project Structure

linux-system-management-3/
├── README.md
├── outputs/
│   ├── 01-sshd-status.txt
│   ├── 01b-sshd-port-check.txt
│   ├── 02-sshd-config.txt
│   ├── 03-pxe-theory.txt
│   ├── 04-resolv-nsswitch.txt
│   └── 05-dns-tools-output.txt
└── screenshots/
    ├── 01-sshd-status.png
    ├── 02-sshd-config.png
    ├── 03-pxe-theory.png
    ├── 04-resolv-nsswitch.png
    └── 05-dns-tools-output.png

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⚙️ Command Execution & Results

1️⃣ SSH Service Status & Port Validation

sudo systemctl status sshd
sudo ss -tuln | grep :22
sudo lsof -i :22

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2️⃣ SSHD Config Check (Hardened)

sudo grep -Ei 'permitrootlogin|passwordauthentication|port' /etc/ssh/sshd_config

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3️⃣ PXE Theory Notes (Manual)

Create a markdown or text file summarizing:

• What is PXE
• How DHCP and TFTP are used
• The boot process sequence

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4️⃣ DNS Resolution Files

cat /etc/resolv.conf
cat /etc/nsswitch.conf | grep hosts

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5️⃣ Name Resolution Tools

host google.com
dig google.com +short
nslookup google.com

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✅ Summary

This project demonstrates Linux+ exam topics for securing and verifying SSH, understanding PXE boot concepts, and managing DNS resolution.
All outputs and screenshots reflect real terminal execution and audit-worthy configuration.

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🎯 Linux+ Portfolio Completed

✅ linux-system-management-1
✅ linux-system-management-2
✅ linux-system-management-3

Each project reflects real-world readiness and hands-on verification.