Networking Fundamentals

The networking every automation engineer needs — taught one screen at a time. Ten lessons, each 6–12 minutes, in the screen-by-screen, predict-then-reveal style. Start at lesson 01 and finish in about 90 minutes. No prior networking knowledge required.

• Lesson 01 — What is a network — Two devices, one cable, the smallest possible network. Build it from scratch.
• Lesson 02 — IP addresses — Every device needs an address. Here's how IPv4 works on the plant floor.
• Lesson 03 — IP classes & private networks — Why your factory uses 192.168 and your phone doesn't.
• Lesson 04 — Subnet masks — How devices know who's on their network — with a live CIDR slider.
• Lesson 05 — MAC vs IP — Two addresses per device, and which one travels where.
• Lesson 06 — Ports & sockets — Same IP, many services — the port concierge.
• Lesson 07 — TCP vs UDP — Reliable vs fast — and the packet race that shows the difference.
• Lesson 08 — The OSI model (practically) — 7 layers, but only 4 you'll touch daily.
• Lesson 09 — Routers, switches, gateways — Build a working network and break it on purpose.
• Lesson 10 — Industrial network topologies — Star, line, ring — and the cut-the-cable simulator.

Why plant-floor networking is its own skill

An office network can tolerate a dropped packet. A production line often cannot: a PLC that waits too long for a reply from a drive, a remote I/O rack or an HMI raises a communication fault and the machine stops. Most of those faults are not mysterious. They come from the same handful of causes — two devices sharing an IP address, a subnet mask that puts a device on the wrong side of a router, a port that is blocked, or a cable and switch topology that was never drawn down on paper.

These ten lessons teach exactly those causes, in the order you meet them: what a network is, how IPv4 addresses and private ranges work, what a subnet mask actually decides, how a MAC address differs from an IP address, what ports and TCP versus UDP are for, how the OSI model helps you decide where to look first, and how switches and topologies shape traffic. Every lesson is built around something you change and then watch react, not something you read and forget.

What you will be able to do afterwards

• Pick a valid address and mask for a new PLC, HMI or drive without clashing with anything already on the machine network.
• Say whether two devices can talk directly or only through a router, before you plug anything in.
• Read a connection error from a protocol such as Modbus TCP, EtherNet/IP or Profinet and work out which layer to check first.
• Explain to an IT department what a controls network needs, in the words they use.

How the lessons work

Each lesson is a short run of screens. You are asked to predict what will happen, you try it on a small live model, and only then does the explanation appear, so the idea attaches to something you have seen. Nothing needs installing and you do not need an account: progress is kept in your browser, and an account only adds saving it across devices. When you have finished all ten, the free-play Sandbox opens, where you place PCs, PLCs and switches, set their addresses, and test whether a ping gets through. From here the natural next step is the protocols track, which puts these ideas to work on real industrial protocols.