Networking Articles

How to Check Which Ports Are Open on Linux (ss, lsof, netstat & nmap)

Find open ports and the services behind them on Linux using ss, lsof, netstat, and nmap. Clear examples and guidance on when to use each tool.

How to Open and Forward Ports in Linux Firewall (UFW & iptables)

Learn how to open, block, and forward ports in Linux using UFW and iptables. Secure your server while allowing essential services like SSH and HTTP.

What is NAT and Why It Matters for SIP and VoIP Calls

Learn how NAT affects VoIP and why it often leads to issues like one-way audio or dropped calls. This guide covers Linux CLI checks, Asterisk configuration fixes, and NAT traversal methods to keep your calls working smoothly.

Understanding Ports and Protocols in Networking - A Beginner’s Guide with CLI Examples

New to networking? This guide explains ports and protocols, why they matter, and how they work together. With simple CLI examples, you’ll learn to check ports, test connections, and understand the basics of how devices communicate.

How to Set a Static IP Address in Linux Using nmtui

Learn how to assign a persistent static IPv4 address on Debian, Ubuntu, CentOS, Rocky Linux, and other NetworkManager‑based distributions using nmtui. Beginner‑friendly, step‑by‑step guide with screenshots and troubleshooting tips.