Network Simulator
A student watches what really happens when a web page loads. It opens on a small internet: a home network, an internet provider, a DNS server and a web server. The computer asks for an address, looks up isp.com, and fetches the page through two routers, and every packet can be seen crossing the wires. It runs in a browser tab, so it works on the Chromebooks where desktop network simulators will not install. Free, and no account needed to try it.
Using this with a class? Make a free class and add your students yourself: each gets a username and password, with no email or Google account needed. Or give them one join code. Using Google Classroom? Post the link there; with a free class, the link also puts each student in your class, so you see their work. mytekDev is also available from the Google Workspace Marketplace, so your school's Google admin can install it for everyone.A first lesson: Everyone runs the same three steps, address, name lookup, page, and then explains which step each packet on the screen belonged to.
Set up a free class Share to Google ClassroomWhat a student actually does
They start with a small internet that is already wired up, and a computer that has no address yet. They right-click it and ask for one, and watch the request go out to the DHCP server and the answer come back. Then they look up isp.com and follow the question to the DNS server. Last, they open the web browser, type isp.com, and watch the request cross the home router, the internet provider's router, and arrive at the web server, and the page appear.
From there they build and break networks of their own: computers, switches, routers, firewalls and servers for DHCP, DNS, web, email and games. They can split networks with VLANs, set firewall rules, inspect any packet layer by layer the way network engineers do, and run safe demonstrations of attacks like a rogue DHCP server or a man-in-the-middle router to see why HTTPS matters.
Three conversations, one page. The computer got 192.168.1.100 from the DHCP server, asked the DNS server where isp.com lives, and fetched the page from 67.12.241.4 through two routers. Typing the address directly skips the DNS question and still works, which is the clearest way to see what DNS is for.
What they are learning while they play
Nothing here is presented as a lesson. This is what the activity is made of.
| What the student does | What it is |
|---|---|
| Asks the DHCP server for an address | IP addressing. Every device on a network needs a number to be reached at. DHCP hands them out so nobody types them by hand. |
| Looks up isp.com | DNS. Names are for people; networks use numbers. DNS is the lookup that turns one into the other. |
| Loads the page by name, then by number | What DNS is for. Typing the address directly still works. The name was only ever a convenience. |
| Watches the request cross two routers | Routing. A router passes traffic between networks. Each one only needs to know the next step, not the whole path. |
| Sees the home network and the ISP in separate boxes | Subnets. 192.168.1.x is one network, 67.12.241.x another. Addresses show which network a device lives on. |
| Opens a packet in the inspector | Layers. Every packet carries an Ethernet frame, an IP header and the message itself, one inside the other. |
| Reads HTTP 200 OK in the browser | Client and server. The browser asks, the server answers with a status code and a page. 404 means the file was not there. |
| Runs the rogue router demonstration | Why HTTPS matters. A device in the middle can read plain HTTP. HTTPS keeps what it sees scrambled. |
How to tell whether it landed
Ask, and let them show you. A student who has understood it can answer these without help.
- Before DHCP, the computer's address was blank. Why could it not do anything yet?
- What did the DNS server send back, and why did the browser need it?
- You typed 67.12.241.4 instead of isp.com and the page still loaded. What step got skipped?
- Point to each router the request crossed. What does each one know about the path?
- Unplug a cable in your head: which one would stop the page from loading, and which would not matter?
Use it in your subject
Not a technology class? Then the app is how students show what they learned in your unit. More projects for every subject.
Digital citizenship
Run the safe demonstration of a rogue server on a network and explain, in plain words, why a public Wi-Fi network deserves some suspicion.
Practical notes
- AgesAges 11 through high school, and intro networking and IT courses in college. Younger students follow the three steps; older ones build networks, subnets, VLANs and firewalls from scratch.
- TimeAbout two minutes for the three steps. A satisfying session is thirty to forty-five minutes of building and breaking networks.
- EquipmentAny computer or Chromebook with a modern browser and a mouse or trackpad that can right-click. Nothing to install.
- CostFree. The app has no paid tier.
- PrepNone. Open the page and go. Reading this page first takes about four minutes.
- In a groupEveryone can run the same network, then each student breaks one thing and the class works out what failed.
For co-ops, microschools, and classrooms
Run the three steps together on the board, then hand out a broken network: a wrong address, a missing route, a firewall rule in the way. Students trace packets until they find the fault. It is the same thinking a network technician does, without a rack of equipment.
- Nine ready-made networks, from a home setup to a school lab, an office with VLANs, a DMZ and 802.1X authentication.
- Safe attack demonstrations: rogue DHCP, a man-in-the-middle router, and ARP poisoning.
- No install, no lab equipment, no per-seat license. Chromebooks are fine.
- A free teacher account covers up to 50 students, and student work is private by default.
Common questions
Is the Network Simulator free?
Yes. It runs in your browser and there is no paid tier. A free account adds saving, but nothing on this page is behind a paywall.
Will it run on our school Chromebooks?
Yes. It installs nothing and runs in any modern browser, Chromebooks included, with no Linux setup and no extension. It uses right-click menus, so students need a mouse or a two-finger trackpad click.
Is this a Packet Tracer alternative for Chromebooks?
For the concepts, yes. Packet Tracer is Cisco's desktop simulator: it installs on Windows, macOS and Ubuntu, and downloading it needs a Networking Academy account, so it has no Chromebook version. This one runs in any browser tab with no install and no account. It covers addressing, DHCP, DNS, routing, switching, VLANs, firewall rules, ping, traceroute and packets you can open layer by layer. It does not teach Cisco's command line: devices are set up in menus, not by typing router commands.
Can I use it in a networking or IT course?
Yes, as the hands-on part of the addressing, DHCP, DNS, routing, VLAN and firewall units. Students build a network, break it, and trace the packets to find the fault, which is the troubleshooting those units ask for. Where a course needs router configuration by command line, pair it with a tool that teaches that.
Does my child need an account to try it?
No. The demo on this page is the complete simulator with a starter network. Make a free account and the network you changed comes with you as your first project.
What ages is it for?
Ages 11 through high school, and adults starting to learn networking. The first three steps need no background at all.
What subject can I log this as?
Most families log it as computer science or information technology. Addressing, DNS and routing are networking, and the attack demonstrations are cybersecurity. The table above lists specifically what is covered, so you can pick the label your records need and point at the evidence.
Still have a question? Ask us, and a person will write back.
Where to go next
Badge kits and learning kits
Step-by-step projects in Network Simulator that end with a certificate: for a scout badge, or for homeschool families and classes.
- Stay safe online: layers and messages: Girl Scouts Brownie Cybersecurity 1: Basics badge, or the learning kit for grades 2-3
- How computers talk: Girl Scouts Junior Cybersecurity 1: Basics badge, or the learning kit for grades 4-5
- Safe anywhere: travel, Wi-Fi and devices: Girl Scouts Senior Cybersecurity 2: Safeguards badge, or the learning kit for grades 9-10
- Inside job: investigate a company hack: Girl Scouts Senior Cybersecurity 3: Investigator badge, or the learning kit for grades 9-10
Start with Network Simulator
Trying it costs nothing and takes about five minutes. An account is what makes the work last.
The Network Simulator is one of the making apps on the platform, built on the open-source Education Network Simulator by Jorge García Ochoa de Aspuru. It is a place to make things, not a course, and it is not a substitute for a teacher: it is at its best when an adult asks the questions above and takes the answers seriously.
Based on the Education Network Simulator by Jorge García Ochoa de Aspuru, used under the GPL-3.0 license. Source.
Page last reviewed September 2026.
Google, Google Classroom and Chromebook are trademarks of Google LLC.