Networking Fundamentals: What I Have Learned So Far
IP addresses, protocols, ports — breaking it down simply
Networking is the foundation of everything in IT and cybersecurity. You cannot protect a system you do not understand. These are the core concepts I have been working through and how I think about each one.
IP Addresses
Every device on a network has an IP address — a unique identifier that tells other devices where to send data. Think of it like a mailing address for your computer.
There are two types:
- IPv4 — the familiar format:
192.168.1.1. Four numbers separated by dots, each between 0 and 255. - IPv6 — the newer format designed because we ran out of IPv4 addresses. Looks like
2001:0db8:85a3::8a2e:0370:7334.
IP addresses can be public (visible on the internet) or private (only visible inside your local network like your home WiFi).
Ports
If an IP address is the building, a port is the specific door. When your browser loads a website, it connects to port 80 (HTTP) or 443 (HTTPS). When you SSH into a server, it is port 22.
There are 65,535 possible ports. The ones below 1024 are “well-known” ports assigned to specific services. Knowing common port numbers is something every IT and security professional memorizes over time.
Protocols
A protocol is a set of rules that defines how two devices communicate. Common ones:
| Protocol | What it does |
|---|---|
| TCP | Reliable, ordered delivery — used for web traffic, email |
| UDP | Fast, no guarantee of delivery — used for video, gaming |
| DNS | Translates domain names (google.com) to IP addresses |
| HTTP/S | How browsers request web pages |
| DHCP | Automatically assigns IP addresses to devices on a network |
Why This Matters for Security
Every one of these concepts is a potential attack surface. DNS can be spoofed. Open ports can be scanned and exploited. Understanding the normal behavior of a network is what lets you spot abnormal behavior — which is the core job of anyone working in a SOC (Security Operations Center).
I am still learning all of this. But the more I study, the more the pieces connect. Networking is not something you memorize — it is something you gradually understand by seeing how it all fits together.
