VirtualBox: Configuring Static IPs for VMs

06.14.2012 00:57 by kbeckman | Comments

Late last year, I wrote about a hack I came up with for configuring a VirtualBox guest OS with DHCP and ensuring it always got the same IP address. After a new project and some new insight, I’ve figured out a new way that deprecates all of the information in that post. Under that configuration, I assumed that the only way to get a static IP address for a Windows guest OS was to join it to the corporate domain – I was wrong. In the steps that follow, I’ll explain how to set up VirtualBox networking and the network settings for Windows and Ubuntu guests to support static IPs on your VMs. This will make it possible for you to connect from VM-to-VM (provided they’re both running) and for your host OS (in this case Mac OSX) to connect to each VM via static IP.


Step 1: VirtualBox Network Settings

To enable static IP addresses on your VirtualBox VMs, you’ll first need to setup a Host-Only network. The host-only network is a virtual network provided by VirtualBox that is visible only to the Host OS and its virtual machines. VirtualBox should setup a default host-only network during installation, but if it doesn’t you can add one pretty easily. Go to VirtualBox’s application menu and select Preferences – Network. Here you’ll be able to add a host-only network if it doesn’t exist… If desired, you can also configure multiple host-only networks allowing you to create various scenarios where VMs are networked together or fenced-off from each other.


virtualbox networking

VirtualBox Host-Only Networks


Below are my VirtualBox network settings. As you’ll notice, I’ve enabled the DHCP server on the host-only network albeit unnecessary. I just wanted to show that you can have it enabled and still assign your VMs static IP addresses.


host-only adapter          host-only dhcp

VirtualBox Host-Only Network Adapter and DHCP Server Settings


Step 2: VirtualBox VM Network Adapter Settings

In this scenario, your VMs will need two network adapters – a NAT adapter for Internet connectivity; and a Host-Only adapter for the network we configured in Step 1. When you create your new VM settings, VirtualBox should add a NAT adapter by default so you shouldn’t have to do anything here.


vm nat adapter

Virtual Machine Settings: NAT Network Adapter


Enable the host-only adapter by clicking the Enable Network Adapter checkbox on the Adapter 2 tab. Select Host-Only Adapter from the Attached To combo box and select the host-only network you created in Step 1 in the Name combo box. If you only have one host-only network, this will already be selected… Please note this is a single VM configuration. You’ll have to add the host-only adapter to all of your participating VMs.


vm host-only adapter

Virtual Machine Settings: Host-Only Network Adapter


Step 3 (Windows): Static IP Configuration (Host-Only Network)

Setting up a static IP on a Windows machine is fairly straightforward as the IPV4 settings dialog should be familiar to almost everyone… Below I’ve configured the Default Gateway and Preferred DNS Server boxes to contain the host-only network adapter address configured in Step 1 ( I’ve assigned a static IP similar to the default gateway incrementing the address’s last number by one. There is no configuration necessary for the NAT network adapter. Below you’ll also notice a screen shot of my Windows network properties. For reference purposes only, I renamed the machine’s networks to reflect the names of the VirtualBox network adapters.


windows ip settings          windows network settings

Windows IPV4 Configuration Settings


Step 3 (Ubuntu): Static IP Configuration (Host-Only Network)

Configuring a static IP in Ubuntu (I’m using the latest version available, 12.04) is just as straightforward as the Windows configuration. Again, you’ll only need to configure the host-only network adapter – the settings are exactly the same as they were for the Windows machine except for the IP address. Both the Default Gateway and Preferred DNS Server should be set to the host-only network adapter address configured in Step 1 ( Just choose your static IP and you’re finished. As before, for reference purposes I’ve renamed each of my Ubuntu networks to match the VirtualBox network adapter name.


ubuntu ipv4 settings          ubuntu network settings

Ubuntu IPV4 Configuration Settings


All in all, the static IP configuration is really easy. Nothing more to say on this topic…

VirtualBox: Getting Around an Absence of Domain

11.06.2011 00:56 by kbeckman | Comments

UPDATE: The contents of this post are a hack for static IP addresses… I’ve posted a better way here.


A while back, I wrote about the benefits of using cross-platform tools (when available) for software development. The Bottom Line: it allows developers to more easily make the transition to other platforms and new languages. The practice enables developers to use tools they are already familiar with without having to assume the overhead of learning a completely new set of tools along with the new platform or language. So in the spirit of drinking my own Kool-Aid, I’ve recently made the transition from VMWare Fusion to VirtualBox to power my back end SQL Server VM required for our Rails project. Following are the setup details in case anyone else out there is looking to do the same…


A Little Development Environment Background…

My current client is a typical large enterprise with almost all-things Microsoft. Recently, things have changed a bit with our R&D team because we’ve introduced Ruby / Rails development on Mac Book Pro laptops running OSX Snow Leopard. As is the case with many slow-to-adopt IT departments, our Mac Book development machines are either not required or are not allowed to participate in the corporate domain. It seems to me to be either a fear of the unknown or an unwillingness to support something outside of the status quo – I think that answer will change depending on who ask. Reasons aside, local development must mimic the production environment as close as possible to catch any configuration surprises early in the development process.


Step 1: Server Internet Connectivity

Internet connectivity is the easy part… Unless you use some weird, custom setup during your VM build-out, VirtualBox will add a default NAT network adapter to ensure the VM has an active Internet connection. No need for further configuration here.


NAT adapter

Virtual Machine Settings: NAT Network Adapter


Step 2: Pseudo-Static IP Setup to Replace NetBIOS

As I mentioned earlier in this post, our development machines are not part of the corporate domain. The same is true with our development VMs even though they are Windows servers. Joining a server or development machine to the corporate domain is the only way I know of to be able to assign it a static IP address. It’s also the only way I know of to use NetBIOS to connect to the machine using it’s assigned machine name rather than using a static IP address.


Absence of a corporate domain is obviously a problem here… To work around it, we need some VirtualBox customization. I found a solution in adding a second VM network adapter: a Host-Only Network Adapter. It is possible to setup your own local domain using the Windows Server 2008 R2 DNS Server Role. But for a single-server environment, I didn’t want the hassle of setting up and maintaining my own local domain. So I set up the Host-Only adapter to use DHCP. You’ll see from the screenshots below that my DHCP settings provide for a relatively wide range of IP address settings, but the nice thing about VirtualBox’s DHCP server is that it will always assign the first sequentially available IP address to every VM you bring online. In other words, my single VM instance always gets the IP address listed in my DHCP server’s “Lower Address Bound” setting. Bingo! I always get the following IP address for my SQL Server VM:


To change VirtualBox’s DHCP server settings, go to “Preferences” in the application settings. From the “Network” tab, use the edit button (screwdriver icon) to modify the network settings for the host-only network.



VirtualBox Host-Only Network Listing


The DHCP Server will probably not be enabled by default, so be sure to configure it accordingly.


network adapter settings          dhcp server settings

VirtualBox Host-Only Network Adapter and DHCP Server Settings


Now you’re done with the VirtualBox server settings. The last part of the configuration is to add a second host-only network adapter to the SQL Server VM. After adding the second network adapter, be sure to assign it to the same virtual network that was configured for DHCP access. If you’ve only configured a single VirtualBox host-only network, you don’t need to worry about assignment as it will default correctly.


Host-Only adapter

Virtual Machine Settings: Host-Only Network Adapter


Problem Solved!

And that’s it. You’re now ready for server and database connectivity via IP address resolution. Below is a screenshot of the VM’s IP configuration. Notice the dual network adapters.



Virtual Machine IP Configuration