Remote connect to VirtualBox VMs via RDP (VRDP)

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Thomas Joos

Thomas Joos is a consultant for medium and large enterprises in the areas of security, Active Directory, cloud, and AI. He has written over 100 specialized books on IT topics for various publishers and regularly publishes on various portals and magazines. In addition, he works as a trainer for LinkedIn Learning. You can reach Thomas through his blog and X (formerly Twitter).

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Like VMware Workstation, VirtualBox is a type-2 hypervisor, which requires a host OS as a base. This type is particularly suitable for desktop use because of its user-friendly nature and tight integration with the underlying operating system. Such tools support copying files to and from the host via drag and drop and can display individual applications on the host desktop via Seamless Mode.

Using VirtualBox on the Server

However, VirtualBox is also suitable in scenarios typical for a type-1 hypervisor like ESXi or Hyper-V. Such a system usually runs on a server that is managed remotely, requiring a remote display protocol in the VM. In these cases, Oracle VirtualBox is operated in headless mode because the GUI of the guest OS is usually not needed on the server.

Let’s first get the names with their UUID of the VMs because they are required for the various commands to control the VM:

VBoxManage list vms

To start a VM named Windows Server 2022 without displaying it locally, enter the following command:

VBoxHeadless -s "Windows Server 2022"

Alternatively, you can also use the following command:

VBoxManage startvm "Windows Server 2022" --type headless

Starting a Virtual Machine in VirtualBox Headless

The same result can be achieved in the graphical console via Start > Start without GUI.

Install RDP Server

To transfer the guest operating system console from the remote VM to the client device, Oracle provides the VirtualBox Remote Display Protocol (VRDP) and the VirtualBox Remote Display Extension (VRDE). You have to download and install them separately.

Installation of the Extension Pack for VirtualBox

The RDP server offers the advantage of accessing remote VMs without enabling the Remote Desktop feature in the guest OS. It doesn't even need to be supported by the operating system. This mechanism is comparable to vmconnect in Hyper-V. VRDP is compatible with most RDP clients, including mstsc.exe on Windows.

Activate VRDE and configure ports

To activate the VRDP extension, switch to the installation directory of VirtualBox and call up the command-line tool VBoxManage.exe, which, in the following example, enables RDP access to a VM named Windows Server 2022:

VboxManage modifyvm "Windows Server 2022" --vrde on

The VRDP server can be turned off for the same VM with this command:

VBoxHeadless --startvm "Windows Server 2022" --vrde off

By default, the VRDP server in VirtualBox listens for incoming connections on TCP port 3389. You can change this as follows when the VM is not running:

VBoxManage modifyvm "Windows Server 2022" --vrde-port 5000,5010-5012

This is necessary, for example, if RDP is already activated on the server, as TCP 3389 is also the default here. The above command specifies that the VRDE server uses one of the ports from the list, in this example, 5000 or a port between 5010 and 5012.

The settings of the VRDP server can also be adjusted on the Remote Control tab in the VM settings under Display.

Configure RDP Server via the Graphical Admin Console

Change the IP address of the VRDP Server

To display information about the started VM, including those about the VRDP server, use the following command:

VBoxManage showvminfo "VM Name"

Properties of the Switched On Virtual Machine

The IP address and the port used by the VRDP server can be found in the results under the VRDE property. To change its IP address, enter the following command:

VBoxManage modifyvm "VM Name" --vrdeaddress 10.0.20.10

Connecting to the VRDP Server, redirecting USB devices

In RDP clients, you do not use the IP address of the guest operating system but that of the VRDP server. If you have changed the port, you must specify it accordingly here.

Establishing an RDP Connection with a Remote VM under VirtualBox

The VRDP server can also access the USB devices of the client computer so that they are available to the user in the guest OS. The client being used must, of course, support this redirection.

Unlike a direct RDP connection with the guest OS, the VRDP server allows multiple simultaneous Windows VM access.

Summary

VirtualBox is not only usable on a workstation where users interact directly with the console of the guest operating system. It is also suitable for server deployment.

In this case, you typically don’t want to display the screen of the guest OS locally but rather remotely on a client device. VirtualBox offers the headless mode of VMs for these usage scenarios, which allows remote access via the integrated VRDP server. The main advantage is that the operating systems in the VMs don’t have to be configured for remote access because the hypervisor manages the connection.