The OSI Model
How networks really talk, one layer at a time: the seven OSI layers, MACs and ARP, IP and routing, TCP, UDP and ports, encapsulation, and the full journey of a packet, with hands-on terminal walkthroughs.
Topics
Syllabus
8 chapters32 lessons32 challengesMore like this
Networking with the Terminal
Learn how machines actually talk to each other, from the command line. Addresses and DNS, ports and sockets, whether a host is reachable, and HTTP by hand with curl: GET, POST, headers, status codes and HTTPS. Built for IT, support and backend work.
Certificate on completion
- 47
- 47
- 141
LAN Labs
Build, address and troubleshoot small networks in a terminal lab: hosts, switches and routers, cables, IPv4 addresses and masks, ARP, gateways, routing tables, and the classic faults that break real LANs.
Certificate on completion
- 35
- 35
IP Addressing and Subnetting
Master IP addresses from the bits up: binary, IPv4 anatomy, subnet masks, CIDR, subnetting drills, private ranges, network planning with VLSM, and a first look at IPv6. Practice everything in the terminal.
Certificate on completion
- 46
- 46
Make Games with Pygame
Make five games in Python with pygame: move a square, catch falling blocks, Snake, two-player Pong and a game of your own. Every game runs in your browser as you write it.
Certificate on completion
- 41
- 41
- 5
- 14
Binary Tree - Data Structures Series #3
In this course, you will learn about the Binary Tree data structure, create a Binary Tree from zero using your preferred language, and practice coding challenges with it!
- 13
- 11
- 1
Frequently asked questions
How many lessons does The OSI Model have?
The OSI Model contains 32 interactive lessons you can complete at your own pace.
What does The OSI Model cover?
The course is organized into chapters covering: Why Layers, The Physical Layer, Data Link and MACs, The Network Layer, and more.
Is The OSI Model free?
Yes. Every course on Coddy is free to start. You can complete lessons in your browser without any downloads or signup.
Can I get a Terminal certificate?
Yes. Finish the matching Terminal journey and you'll unlock a shareable certificate. See the certifications page for details.
