Mohamed Elmujtaba Elwasila Logo Image
Mohamed Elmujtaba Elwasila

Networking Fundamentals I Actually Had to Understand (While Studying Network+)

While studying for the Network+ exam, I expected networking to be mostly memorisation: ports, protocols, and OSI layers. What I didn't expect was how quickly these concepts showed up in the backend and cloud projects I was building.

Blog Post Featured Image

While studying for the Network+ exam, I expected networking to be mostly memorisation: ports, protocols, and OSI layers. What I didn't expect was how quickly these concepts showed up in the backend and cloud projects I was building.

This post isn't a Network+ summary. It's about the networking fundamentals that stopped being abstract once I started writing and deploying real services.

The Network Is Not Reliable

One of the most important ideas I internalised is that the network cannot be assumed to be reliable. Requests can time out, connections can drop, and partial failures are normal.

This directly influenced how I think about timeouts, retries, and defensive error handling in backend services.

DNS Is a Dependency

DNS felt like 'magic' before. Studying how resolution, caching, and TTLs work made it clear that DNS is just another network dependency that can fail.

This explained many 'works locally but not in production' issues I encountered when deploying services.

Ports, NAT, and Deployment Reality

Understanding ports, NAT, and private vs public IPs clarified why services behave differently once deployed to the cloud. Networking fundamentals turned confusing deployment issues into solvable problems.

HTTP Is Built on an Unreliable Network

HTTP looks simple, but it sits on top of layers that can fail in subtle ways. Concepts like connection reuse, proxies, and load balancers only made sense after understanding what's happening underneath.

Why This Matters for Backend and Cloud Engineering

Networking fundamentals directly affect scalability, reliability, and security. Studying Network+ alongside backend projects changed how I design systems - from assuming things work, to assuming they eventually won't.

Closing

I'm still learning, but networking has shifted from exam material to an engineering tool. The goal isn't memorising protocols - it's building systems that behave well when the network doesn't.