Networking - ITNotes

Networking tutorial - IT technology blog

TCP vs UDP: Key Differences and When to Use Each in Your Network Stack

March 7, 2026

TCP guarantees delivery and ordering through a handshake and retransmission; UDP skips all that for raw speed. Knowing when to pick each protocol — and how to verify what your stack is actually doing — is foundational networking knowledge every engineer needs.

Networking

SSH Tunneling: Secure Access to Remote Services Over Any Network

March 7, 2026

SSH tunneling lets you securely forward ports between machines using an existing SSH connection — no VPN, no firewall changes, no extra software. This guide covers local, remote, and dynamic tunnels with practical examples, persistent setup using autossh, and a systemd service for production use.

Networking

Nmap Network Scanning: How to Detect Open Ports and Vulnerabilities Fast

March 7, 2026

Learn how to use Nmap for fast network scanning and vulnerability detection through real-world incident response scenarios. Covers port scanning, service version detection, NSE vulnerability scripts, and a practical scan sequence for sysadmins and security engineers.

Networking

IPv4 Subnetting Tutorial: How to Calculate Subnets Without Losing Your Mind

March 6, 2026

IPv4 subnetting is the skill that separates networking theory from practical network engineering. This tutorial walks through subnet calculations, CIDR notation, VLSM, and real-world allocation strategies with Python and Linux command examples.

Networking

Fail2Ban: Automatic Brute Force Protection for Linux Servers

March 6, 2026

Fail2Ban automatically blocks IP addresses that repeatedly fail authentication, protecting your Linux server from SSH brute force and web attacks. Learn how to install, configure, and tune it with practical tips from hands-on server hardening experience.

Networking

How to Set Up WireGuard VPN Server on Linux (Fast & Secure)

March 5, 2026

WireGuard is the fastest, simplest way to run a self-hosted VPN server — far less painful than OpenVPN or IPsec. This guide walks through server setup, key generation, peer configuration, and firewall rules on Ubuntu Linux, from a clean install to a working tunnel.