Build Network Topology
This lesson is about doing, not reading: you'll combine every device you've learned so far into a working network on the isometric board.
01The devices in your toolbox
| Device | Role | Layer |
|---|---|---|
| PC | End-user device; gets an IP, sends/receives data | — |
| Switch | Connects devices in one LAN, keeps a MAC table | Layer 2 |
| Router | Connects different networks, routes by IP | Layer 3 |
| Firewall | Filters traffic by rules | Layer 3–7 |
| Internet | The outside world | — |
02The classic lineup
The backbone of a small office network is almost always the same sequence:
code
PC ─┐
PC ─┼─ Switch ── Router ── Firewall ── Internet
PC ─┘
- PCs connect to the switch — members of the same LAN
- The switch connects to the router — the LAN's door to the outside
- The firewall sits between router and internet — border control
03Your mission
- Connect three PCs to a switch
- Connect the switch to a router
- Take the router out to the internet through a firewall
- Fire a packet from a PC and watch its journey
If the packet can't reach its destination, check the cabling: is a PC wired straight to the router? Did you skip the switch? Mistakes are part of the lesson — break it, fix it, try again.
Sandbox · BuilderNetwork BuilderDrop devices onto the board, cable them up, and fire packets — this is the lesson's playground.Open tool04When you're ready: mission mode
Finished free-building? Try building topologies under constraints — limited ports, a tight cable budget:
Sandbox · ChallengeNetwork ChallengeFive missions with star ratings: build the right topology under port and cable constraints.Open tool05Summary
- PC → switch → router → firewall → internet: the classic backbone
- The switch gathers the LAN, the router opens it up, the firewall guards the border
- Building topologies is the fastest way to make device roles stick