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See the Network.
Prove It.

One guided field route from a browser request to packets, kernel state, and production networks.

Start Session 1 Explore Labs

Or play the arcade

Packet Journey
MT Arcade Press Start

First win

Inspect a real browser request in 10 minutes.

Then, in the 45 to 60 minute Browser to Wire systems lab, capture a fresh IPv4 connection and prove why a host with an empty neighbour cache must resolve the next-hop MAC address before its first TCP packet can leave.

A client is on a fresh IPv4 network. Its neighbour cache is empty. What must happen before the first TCP SYN can leave?

Choose a prediction. This is practice, not a grade.



// Built by hand, no frameworks

See the craft before you commit to the course.

Three tools that show what "operate the system" actually means here. Real protocol behavior, not slides.

Browser Lab

Switchboard

Inject a raw Ethernet frame. Predict flood, forward, or filter, then watch a real switch panel learn, look up, and act.

Open Switchboard →
Reference Tool

Subnet Calculator

Type any IP and prefix. Watch all 32 bits update live, network bits and host bits colored apart, no guessing required.

Open Subnet Calculator →
Browser Lab

BGP Explorer

Twelve real autonomous systems on a canvas. Watch the best-path decision tree pick a winner, then hijack a route.

Open BGP Explorer →

// Mission Fieldwork

See the system. Operate it. Prove what happened.

Every field route connects a visual model to a browser tool, a real Linux system, a controlled failure, and evidence you can inspect yourself.

01 / SEEBuild the mental modelFollow the packet and predict what each layer must do.
02 / OPERATEControl the systemChange inputs in a browser tool and watch state respond.
03 / BUILDUse the real primitivesCreate namespaces, links, bridges, routes, and services in Linux.
04 / BREAKChange one conditionIntroduce a bounded failure and predict the result before testing.
05 / PROVEKeep the evidenceRead kernel state and packet captures. Save the result locally.

// The first field route

How Networks Work

🔍
DNS
How domain names resolve to IP addresses
🤝
TCP
The handshake that starts every connection
🔀
NAT
How private IPs reach the public internet
🌐
BGP
The protocol that routes the internet
Open all 18 sessions →