If you’re preparing for a networking, Linux system administration, DevOps, or cybersecurity interview, understanding network ports is a must. Port numbers come up in almost every technical interview because they’re essential for network communication. Yet, many candidates overlook this basic area.
This article covers the top 25 ports you should know by heart, including what each one does, the protocol behind it, and why it matters. Whether you’re a beginner or just need a refresher, this guide is crafted to be simple, practical, and interview-ready.