Networking

Summary

This note is a quick reference for basic network inspection commands. These are useful when checking interfaces, confirming connectivity, or seeing which ports and services are listening on the system.

Commands

Command	Purpose
ip a	show network interfaces and IP addresses
ss -tulpn	show listening TCP and UDP ports with process info

Example usage

ip a
ip route
ss -tulpn

Notes

• ip a is the modern everyday command for checking interface state and addressing
• ss -tulpn is one of the most useful commands for answering “what is listening on this machine?”
• these commands become even more useful when combined with systemctl, journalctl, and process inspection

Related

• Back to Linux Reference
• [Process management](Process management)
• [System Info](System Info)