Networking Fundamentals
Build a working mental model of how computers talk — from a single Ethernet frame to a full HTTPS request across the internet. A core-technology foundation for Cloud, DevOps, Linux, Windows, Security and Data roles alike. Recommended prior knowledge: Cyber Foundations.
What you will be able to do
- Trace a request from one machine to another across a switch, a router and the internet, naming what happens at each hop.
- Read the core evidence a network produces — addresses, ports, DNS, HTTP, a packet capture — and reason about whether a path is healthy or broken.
- Decide whether two addresses share a subnet, pick the right gateway, and diagnose a connectivity failure layer by layer.
Units
- 01
How Networks Work
What a network actually is, the roles machines play on it (client, server, peer), how a device connects through a network interface, and how to read a simple network diagram of a LAN and the wider internet.
BeginnerAvailableWhy you are learning this
Every later unit — and every technology role that touches a network — assumes you can picture where a machine sits and who it talks to. This unit builds that picture from nothing.
- 02
Ethernet & Local Networks
How machines on the same local network actually reach each other: MAC addresses, Ethernet frames, what a switch does, broadcast domains, and how ARP maps an IP address to the hardware that owns it.
BeginnerAvailableWhy you are learning this
Before traffic can cross the internet it has to be delivered locally. Understanding frames, switches and ARP is what makes the difference between 'the network is magic' and 'I can reason about where a packet went'.
Unit contents3
- 03
IP Addressing & Subnetting
How every machine gets a logical address: IPv4, public versus private ranges, the network/host split, subnet masks and CIDR, the default gateway, the routing decision a host makes for every packet, and IPv6 awareness.
BeginnerAvailableWhy you are learning this
'Are these two machines on the same network?' is one of the most common questions in every technical role. Subnetting is the math that answers it — and decides whether traffic even needs a router.
Unit contents4
- 04
Transport & Services
How applications actually connect: ports and sockets, the client/server model, TCP's reliable connection (handshake, sequencing, lifecycle) and UDP's fast fire-and-forget — and how to choose between them.
BeginnerAvailableWhy you are learning this
IP gets a packet to a host; ports and transport get it to the right program on that host. Every service you will ever run, debug or secure lives at a port and speaks TCP or UDP.
Unit contents3
- 05
Core Network Services
The services that make a network usable: DNS turning names into addresses, DHCP handing out configuration, ICMP reporting problems, and NAT, proxies and VPNs reshaping where traffic appears to come from.
BeginnerAvailableWhy you are learning this
When something 'can't connect', the cause is usually one of these services, not the wire. Knowing what each does — and how it fails — is most of practical network troubleshooting.
Unit contents3
- 06
Web & Encrypted Communication
How the web actually works on the wire: HTTP requests and responses, headers and status codes, then how HTTPS wraps them in TLS — the handshake, certificates, and what stays visible versus hidden once traffic is encrypted.
BeginnerAvailableWhy you are learning this
Most of what crosses a modern network is HTTP(S). Reading a request, a status code and a TLS handshake is a daily skill for developers, cloud engineers, admins and defenders alike.
Unit contents3
- 07
Routing, Segmentation & Troubleshooting
How traffic crosses between networks and how it is deliberately controlled: routing and network paths, segmentation and firewalls, and a repeatable, layer-by-layer method for diagnosing why a connection is failing.
BeginnerAvailableWhy you are learning this
This is the unit that turns knowledge into a workflow: given a broken path, work outward from the host through addressing, DNS, routing and firewalls until you find the one layer that failed.
Unit contents4
- 08
Packet Analysis Foundation
Reading the network directly: what a packet capture is, how the layers stack inside one packet, how to pick out a single conversation, follow a stream, apply a simple display filter, and interpret what the traffic is doing.
BeginnerAvailableWhy you are learning this
A packet capture is the ground truth of a network. This unit is the on-ramp to Wireshark, network forensics, deep debugging and every role that ever has to prove what actually crossed the wire.
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Windows & Active Directory Administration
Build a working mental model of Windows — processes, the registry, users and permissions — then how Active Directory lets one team manage thousands of machines and identities. A core-technology foundation for IT operations, system administration, Cloud, DevOps and Security roles alike. Recommended prior knowledge: Cyber Foundations.
Scripting & Automation
Build a working mental model of how programs think — data, logic, functions, files — and use it to automate repetitive work reliably. A core-technology foundation for Cloud, DevOps, Data, Programming, AI and Security roles alike. Concepts are language-agnostic, shown mainly in Python. Recommended prior knowledge: Cyber Foundations.