Network Puzzle Lab: Build the Path, Then Fix the Mistake

This lab turns network vocabulary into a working model.

You will arrange a fictional network, assign documentation addresses, diagnose configuration mistakes, and explain how traffic should move.

No real network scanning or configuration is required.

The puzzle pieces

Your fictional network includes:

• 4 student workstations
• 1 printer
• 1 local server
• 1 switch
• 1 wireless access point
• 1 router/firewall
• internet connection

Your teacher provides cards or an interactive canvas for arranging the devices.

Part 1: build the topology

Place the devices so that:

• wired local devices connect through the switch
• wireless devices connect through the access point
• the local network reaches other networks through the router
• the printer and server remain reachable to approved local users

Then draw the path from one Chromebook to the local server and from the same Chromebook to a public website.

Part 2: assign fictional IPv4 addresses

Use the documentation network:

192.0.2.0/24

Example assignments:

router     192.0.2.1
server     192.0.2.10
printer    192.0.2.20
student-1  192.0.2.101
student-2  192.0.2.102

Assign the remaining devices without duplicating an address.

Part 3: inject mistakes

The teacher provides one or more failure cards.

Duplicate address

Two workstations both use 192.0.2.101.

Wrong network

One workstation is configured as 198.51.100.25 while the classroom exercise expects 192.0.2.0/24.

Missing router

A workstation has a valid local address but no configured default router.

Wrong physical path

The printer is shown connected directly to the internet instead of the local network.

For each mistake:

• state the symptom you would expect
• identify the incorrect configuration or topology
• explain the smallest correction
• identify what remains reachable before the correction

Do not diagnose from one symptom

"The internet does not work" is not enough to identify the router as the cause.

Possible causes include:

• local Wi-Fi issue
• wrong IP configuration
• missing route
• DNS problem
• remote service failure

This lab limits the possible causes so you can learn the reasoning pattern.

Pizza-party-style address challenge

Treat each table in a fictional event room as a subnet or local group in the classroom model.

Students receive device/address cards and must determine:

• which devices belong to the same local network
• which communication needs routing
• which addresses are duplicates or invalid for the stated scenario

The goal is to make addressing visible and social, not to memorize subnet arithmetic.

Build the final network dossier

Your dossier must include:

• topology diagram
• address table
• two path traces
• diagnosis of at least three injected mistakes
• one security boundary, such as guest versus internal network
• one availability risk and one control

Evidence for Lesson 3

Submit the network dossier and a short architecture defense.

Finish with:

The first thing I would verify when a device cannot communicate is ________ because ________.

Networking becomes easier when you can separate physical path, local addressing, routing, and application behavior instead of calling every failure "the Wi-Fi."