VirtualBox has a built-in server with Remote Desktop Protocol (RDP) service that allows seeing the output of a virtual machine remotely from another computer. This method called ‘Remote Display’. This post explains how to set it up, connect and use multiple remote displays in Oracle VirtualBox.
The best part of the remote display is it doesn’t require any network connectivity between VirtualBox virtual machine and other networked computers where you want to connect. The network connectivity required only between VirtualBox host computer (Where VirtualBox is installed) and computer you are trying to connect.
Remote display option in VirtualBox helps to reduce the workload of the host computer. For example, when you have several virtual machines on a single host computer, you can start those virtual machines in headless mode (Virtual Machine runs in the background, no console view) and connect remotely from other computers. So, it reduces the graphics and video output requirements/resources on the host computer.
How to Enable Remote Display in VirtualBox Virtual Machine,
1) Go to Display option in settings.
2) Click on Remote Display tab.
By default remote display options are disabled in VirtualBox, click Enable Server option. The default port is 3389, Authentication method can be changed as per your security requirements.
That’s it, remote display for a particular virtual machine is enabled, and you can control this machine from any other networked computers.
How Remote Display Works in VirtualBox
Remote display in VirtualBox is not at all connected with the Operating System inside the virtual machine. When the remote display server is enabled for a particular virtual machine, VirtualBox console broadcasts virtual machine’s output window through the specified port via the host IP address. Therefore any remote desktop (RDP) request comes to host computer via this port number, will be able to get virtual machine’s display based on the authentication method.
How to Connect Remote Display in VirtualBox.
Use any Remote Display Protocol (RDP) viewers; Windows Remote Desktop Connection can be used to connect virtual machine’s remote display.
1) Open remote desktop connection on any other computer which can communicate to VirtualBox host (Physical) computer.
2) Type the IP address of the host machine with the port number.
IP Address: Port number (specified during remote display settings in the virtual machine)
3) As shown below, I got the remote desktop connection and able to view and work on the virtual machine no matter what operating system it is. I could connect to Mac OS virtual machine from Windows 10 host
How to Connect Multiple Remote Displays
Okay, now the question is how to connect multiple virtual machines using remote display? We should be able to connect all virtual machines while using VirtualBox RDP server.
The remote display server port for each virtual machine should be different to enable multiple remote connections. For example, when my Mac virtual machine has server port 3389, another machine can have 3388 or 3387 or any available ports on the host computer. Server Port numbers can be changed as mentioned earlier.
Each virtual machine can be connected and controlled by a remote desktop viewer by typing VirtualBox server host IP with different port numbers.
Make sure that the firewall on the host computer is set to allow remote desktop protocol (RDP) connections and port numbers.
Remote Display in VirtualBox is a nice feature to reduce the resource usage on the host computer. Also, the remote display feature enables multiple users from multiple computers to access virtual machines that run on a single VirtualBox server host computer. This will be an idea for testing environment.
Feel free to share your experience with remote display feature and how it is useful for you.