Quickstart

In this guide you ask Claude for a Packet Tracer lab, let the skill model and validate it, explore the interactive diagram and assemble the lab in Packet Tracer. The example is the classic CCNA lab: three VLANs, router-on-a-stick and DHCP.

#Before you start

• Claude Code installed and signed in.
• Node.js 22.18 or newer — the skill's toolkit runs TypeScript natively. Check with node --version.
• Cisco Packet Tracer, only for step 6 (assembling the lab).

1. #Install the skill

   Terminal

   npx skills add whetstone-dev/network-engineering
   

   Restart Claude Code so it picks up the skill. To check it is there, type / in Claude Code and look for network-engineering in the list.

   Prefer git, or want it for a single project? See the installation options.

2. #Ask for a lab

   Open Claude Code in an empty folder:

   Terminal

   mkdir my-lab
   cd my-lab
   claude
   

   Then describe what you need, the way you would brief a network engineer:

   ›

   I need a Packet Tracer lab with 3 VLANs (Sales, Admin and IT), one router, two switches and DHCP for the PCs.

   You don't have to call the skill: it activates on its own for networking requests. To invoke it explicitly, start with /network-engineering.

3. #Let Claude model and validate it

   Claude doesn't jump straight to commands. It follows the skill's design flow:

   1. Asks only what changes the design, and states the assumptions it makes — for example, that each gateway is the first usable IP.
   2. Writes the network model to networks/<name>.net.json: devices, exact ports, VLANs, addressing and the tests that prove your requirements.
   3. Runs the quality gate with netlab validate:

   Output

   OK    ping PC1 → PC3 (expected success): Round trip OK
   OK    ping PC1 → PC2 (expected success): Round trip OK
   OK    ping PC5 → 192.168.99.11 (expected success): Round trip OK
   OK    ping PC4 → 192.168.20.1 (expected success): Round trip OK
   
   Summary: 0 errors, 0 warnings, 7 notes · 8 devices, 7 links
   

   Notes are informational — here, the DHCP leases the toolkit simulates and which switch is the STP root. If there are errors, or a test cannot be decided, Claude fixes the model and validates again. No configuration is generated until the gate passes.

4. #Get your files

   Claude then runs netlab build, which writes every artifact next to the model. Change the model, never the outputs: they are regenerated from it.

   Files

   my-lab/
   └── networks/
       ├── lab-3vlan.net.json  # the model: edit this
       └── lab-3vlan-build/
           ├── topology.html  # interactive diagram
           ├── README.md  # inventory, addressing, ports
           ├── configs/  # one file per device
           │   ├── R1.txt  # IOS CLI
           │   ├── SW1.txt
           │   └── PC1.txt  # Packet Tracer GUI steps
           ├── topology.mmd  # Mermaid version
           └── analysis.json  # diagnostics and tables
   

   In the chat you also get a short summary: design decisions, the addressing table, how to verify it and what to check if something fails.

5. #Explore the diagram

   Open topology.html with a double click — no server or internet needed. Things to try:

   • Click a device to open the inspector with its interfaces, VLANs and configuration.
   • L3 switches to the logical view of routers and subnets.
   • The VLAN filter shows the path of a single VLAN.
   • Tests lists every ping; click one to highlight its path, hop by hop.
   • SVG / PNG export the diagram for reports.

   Want to try it now? The home page embeds real diagrams generated by the toolkit.

6. #Assemble it in Packet Tracer

   The skill does not create .pkt files; it gives you everything needed to build the lab by hand in a few minutes. Use the generated README.md:

   1. Place the devices listed under Inventory, with the same models (2911 router, 2960 switches).
   2. Cable them exactly as listed under Connections. Ports matter: the trunk to the router is on SW1 Gi0/1, and each PC sits in the access range of its VLAN.

   Link	Source	Target	Type	VLAN
   L1	R1 Gi0/0	SW1 Gi0/1	trunk	10,20,30,99
   L2	SW1 Gi0/2	SW2 Gi0/1	trunk	10,20,30,99,999
   L3	PC1 Fa0	SW1 Fa0/1	access	10

   3. Paste each configuration from configs/<device>.txt into the device CLI, starting at user EXEC (Router>). For PCs, follow the GUI steps in their file: Desktop › IP Configuration › DHCP.
   4. Verify on the devices: check each PC's address with ipconfig, ping across VLANs, and on the switches and router run:

   Cisco IOS

   show interfaces trunk
   show ip dhcp binding
   

   5. Save: generated configurations never save the startup-config. Run copy running-config startup-config on each device, then save the .pkt file.

7. #Iterate in plain words

   Changing the network is another request:

   ›

   Add a guest VLAN 40 that cannot reach the IT VLAN.

   Claude edits the model, adds a test that expects the guest-to-IT ping to be blocked, validates again and regenerates every file. The diagram, the documentation and the configs never drift apart, because they all come from the same model.

   To see exactly what changed, ask Claude to compare it with the previous version: netlab diff produces a change report and a diagram that marks what was added, modified or removed.

#Next steps