Networking

The Physical Layer

Getting Started

You'll learn the basics of how data is represented, sent, and measured in networking.

How Data Travels

Explore how data travels through physical cables and wireless signals, and the factors that affect signal quality along the way.

Cabling

Explore the different types of network cabling (copper and fiber) and how they're structured, connected, and used in real-world networks.

Hardware

Get familiar with the hardware that makes networks work, from simple to not-so-simple ones.

Network Speed and Standards

Learn what determines network speed, and how physical limits and standards shape that performance.

From Bits to Signals

Learn how raw bits get turned into signals through encoding, modulation, and signal processing.

The Data Link Layer

MAC Addresses

Learn how devices identify each other on a local network, and how these addresses are structured, assigned and used.

How Switches Forward Frames

Find out how switches move data by learning MAC addresses, building forwarding tables, and deciding when to send, flood, or filter frames.

Preventing Loops

Learn why Layer 2 loops are dangerous and how networks prevent them using Spanning Tree and modern techniques.

Framing

Explore how data is packaged into frames for Ethernet and Wi-Fi, and how networks use special frame types to organize traffic.

How Devices Share the Network

Find out how networks let many devices take turns using the same connection, from simple collision methods to modern scheduling and wireless sharing.

Controlling Data Flow

Learn how networks keep data moving smoothly without getting overwhelmed.

Detecting and Fixing Errors

Get familiar with how networks handle transmission errors, from detecting corrupted data to correcting or retransmitting it.

Adding Structure to Data

Learn how networks structure raw data into blocks using techniques that improve reliability and help receivers stay synchronized.t

Linking Layer 2 and Layer 3

Learn how Layer 2 connects to Layer 3, and how it helps organize and identify higher-level network traffic.

Managing Network Links

Find our how network links are established, maintained and closed.

The Network Layer

IP Addressing

Explore how IP addresses work in IPv4 and IPv6, from their structure and behavior to how they're used for routing and communication across networks.

Mapping IP Addresses to Devices

Learn how IP addresses are mapped to physical devices using ARP and NDP, and how systems discover and verify their neighbors.

How Routers Make Decisions

Find out how routers decide where to send packets using routing tables and policies to choose the best path across networks.

How Routers Learn Routes

Explore how routers discover paths across networks using protocols like OSPF and BGP, as well as how those routes are shared and controlled.

When Packets Are Too Big

Learn what happens when packets are too big for the network.

IP Network Protocols

Get to know IP-related protocols that help networks communicate (and provide cool stuff like multicast, tunneling and basic security).

Troubleshooting IP Networks

Learn how to troubleshoot IP networks with some simple tools and techniques all of us use.

Modern IP Networking

Get an overview of how modern networks are designed and connected using NAT, VPNs, SDN, and cloud-based networking.

The Transport Layer

TCP

Get to know TCP - keeps internet connections reliable.

UDP

Get to know UDP - a protocol used when speed matters more than reliability.

Breaking and Rebuilding Data

Learn how data gets split into smaller pieces and put together again (and how we handle errors along the way).

The Session Layer

The Presentation Layer

Structuring and Encoding Data

Find out how data is structured and encoded so systems can understand each other, from character sets to serialization methods.

Making Data Smaller

Explore how compression reduces data size to save bandwidth and improve performance, and how that interacts with security and encryption.

Protecting Data

Learn how data is protected while it moves across networks.

The Application Layer

Web and API Communication

Learn how websites and apps talk to each other, plus how they stay secure and manage access.

How Systems Exchange Messages

Explore how systems exchange messages behind the scenes, from email to event streams.

How Systems Find Each Other

Find out how systems find and identify each other, from DNS to directory services.

Authentication and Authorization

Explore how system verify who you are and decide what you're allowed to do.

Remote Access and Files

Find out how systems access files and shared resources (including other devices) over a network.

Real-Time Communication

Learn how real-time communication works on the internet, from voice and video calls to live sessions.