Home Virtual Lab: Networking Virtual Machines Together on VirtualBox

I was lucky enough to buy a couple of extra computers from an auction, but usually having extra computers and networking computers for experimenting and penetration testing just isn’t feasible for students. In my previous project, I gave instructions on how to install virtual machines in preparation to set up a virtual lab using Oracle VirtualBox. Here I’m going to explain how to actually allow them to talk to each other and to the Internet.

I’ll expand on this project page later to explain some of the why’s, but I wanted to get the steps out there right away.

Assuming you already have 2 VMs, we’re going to start by allowing each of them to talk to the Internet.

• If the VM is running, shut it down (don’t just save the machine state, but actually turn it off)
• With the VM highlighted in VirtualBox, go to Settings > Network and make sure the Enable Network Adapter box is checked. By default, it should be.
• Also by default, the Attached to drop-down menu should be on NAT. If not, select NAT. This will allow the VM to get to the Internet
• Go ahead and click OK to save the settings, then start the VM to check
• Open a web browser and check if you can reach the Internet
• Now run ifconfig (for Linux) or ipconfig (for Windows) to discover your IP address. It should be 10.0.2.15, since that’s the default for the NAT network option

Alright, good. Now it’s time to let them talk to each other.

• Shut down the VMs again, then open up the Network settings for each one
• In VirtualBox, click File > Host Network Manager
• Click Create to make a new adapter. This is basically like getting a new NIC for your computer, but it’s also like getting a new router to connect multiple computers together.
• For the purposes of this tutorial, just select the Configure Adapter Automatically option, and on the DHCP Server tab, check the box to Enable Server. If you wanted, you could set the network manually, and then also set the IP addresses on each machine manually. You would want to do this if you were hosting a web server, or an FTP server, or something, but in this case the automatic settings are just fine.
• Click Apply
• Now, for each VM, open the Network Settings again
• Click on the Adapter 2 tab and enable it with the checkbox
• Now, attach this adapter to the Host, but select Host-only Adapter from the drop-down menu
• Click the Advanced option, then beside the MAC Address box, click the Refresh icon
• Click OK and then start up your VMs
• This time when you find the IP addresses, you should still have the 10.0.2.15 address, but it should also have another address in the same range as the Host-only adapter you set up earlier. Find those IP addresses, and then try to ping them from each other.

CONGRATULATIONS! You now have a virtual lab you can use for some basic penetration testing!