By Fathalla Ramadan
March 2026
Tested on Windows 10/11 with VirtualBox – Free & Legal
If you want to build realistic enterprise labs—like a client PC talking to a Windows Server through a Cisco router, you can add Windows VM to GNS3. This guide shows you how using free tools only, no piracy.
Works with Windows 10/11 Evaluation ISOs (free from Microsoft)
Uses VirtualBox (free for personal use)
Fully compatible with FRRouting, VyOS, or Cisco Modeling Labs (CML) routersNote: As of 2026, Cisco no longer provides public downloads of IOSv, and DevNet images are licensed only for CML—not GNS3. This guide uses legal alternatives that still deliver real-world lab value.
What You’ll Need
- GNS3 installed (see GNS3 Windows Legal Setup Guide)
- Oracle VirtualBox (download from virtualbox.org)
- Windows ISO (get free evaluation versions from Microsoft Evaluation Center)
- Example: Windows Server 2022 Evaluation or Windows 10 Enterprise Evaluation
- At least 8 GB RAM (16 GB recommended)
Ensure your CPU supports Intel VT-x or AMD-V—and that it’s enabled in BIOS. On Windows 11, also disable Core Isolation → Memory Integrity.
Step 1: Install VirtualBox
- Download VirtualBox + VirtualBox Extension Pack
- Run the installer as Administrator
- Restart your PC if prompted
Do not install “Guest Additions” yet—we’ll do that inside the VM later.
Step 2: Create a Windows VM in VirtualBox
- Open VirtualBox
- Click New
- Name:
WinClientorWinServer - Type: Microsoft Windows
- Version: Match your ISO (e.g., Windows 10 (64-bit))
- Name:
- Allocate 2048–4096 MB RAM
- Create a new virtual hard disk (VDI, dynamically allocated, 25–40 GB)
- Finish setup
Step 3: Install Windows in the VM
- Select your new VM → Settings → Storage
- Under Controller: IDE, click the disk icon → Choose a disk file
- Browse to your Windows ISO
- Click OK, then Start the VM
- Install Windows normally (use default settings)
- After install:
- Install VirtualBox Guest Additions (Devices → Insert Guest Additions CD)
- Enable Auto-login (optional but helpful for labs)
- Disable Windows Firewall temporarily for lab simplicity
Tip: Set a static IP later (e.g.,
192.168.10.10/24) to match your GNS3 topology.
Step 4: Connect Windows VM to GNS3 via Cloud Node (Recommended Method)
Since direct VirtualBox integration is unstable in 2026, use this proven method:
- In VirtualBox, go to File → Host Network Manager
- Create a new host-only network (e.g.,
vboxnet0) - In your Windows VM settings, set Adapter 1 to Host-only Adapter →
vboxnet0 - Assign a static IP to the VM (e.g.,
192.168.56.10/24)
Step 5: Add a Cloud Node in GNS3
- In GNS3, drag a Cloud node to your workspace
- Double-click it → NIO Ethernet → select the same
vboxnet0interface - Connect the Cloud node to your router (FRRouting/VyOS)
- On the router, assign an IP in the same subnet (e.g.,
192.168.56.1/24)
Now your Windows VM can communicate with GNS3 devices through the Cloud node—no broken integration required.
Step 6: Configure Networking
On the Windows VM:
- Open Control Panel → Network → Change adapter settings
- Right-click Ethernet → Properties → IPv4
- Set static IP:
- IP: 192.168.56.10
- Subnet: 255.255.255.0
- Gateway: 192.168.56.1
On the Router (FRRouting example):
configure terminal
interface eth0
ip address 192.168.56.1/24
no shutdown
exit
ip route 0.0.0.0 0.0.0.0 eth0
write memory
“In FRRouting (and most modern systems), we use /24 instead of 255.255.255.0. They mean the same thing—but the syntax is different.”
Step 7: Test Connectivity
- Start both devices in GNS3
- Open Command Prompt in Windows VM
- Run: ping 192.168.56.1
- If you get replies—success! You now have a full client-router-server lab.
Important Notes
- Licensing: Microsoft’s evaluation ISOs are free for 180 days—perfect for CCNA prep
- Performance: Close unused apps; GNS3 + VMs are RAM-heavy
- Backup: Export your VM (File → Export Appliance) once configured
Next Step: Build Real Scenarios
Now try:
- Lab 8.1: DHCP Server on Windows → Clients get IPs via Cisco router
- Lab 10.1: Active Directory + OSPF routing
- Lab 22.1: Client accesses web server over BGP multi-homed ISP
All documented with validation checklists in my IP Routing and Switching Lab Handout Book.
Final Thought
You don’t need expensive gear to simulate enterprise networks.
With free tools and legal images, you can build labs that mirror real-world environments—anywhere in the world.
—
Fathalla Ramadan
Network Architect & Educator | InstaLumeo
