Part 2: Basic — Using a Single Network Interface Setup

In this tutorial I am going to outline one of the most basic ways to connect to a host machine from a guestmachine within VirtualBox from a fresh Windows guestOS install using the main VirtualBox network interface.

This is being done primarily for Microsoft Internet Explorer web browser cross-platform compatibility testing with MAMP-based development tools in macOS. But the basic concepts of this kind of setup can be used for all sorts of things beyond testing web browser cross-platform browser compatibly.

The main drawback of this method is there is no easy way to connect from the host machine to the guest, but that is not a big issue for basic Internet Explorer testing. If you think you might need that extra level of two-way connectivity, skip to the second part of this tutorial where I explain how you can use dual network interfaces with a special host-only adapter in VirtualBox.

Let’s get started.

The most immediate way you can connect to a hostmachine is to use the default VirtualBox user network gateway of 10.0.2.2.

So if you were to connect to MAMP on macOS running on port 8888, the address to connect to would be:

http://10.0.2.2:8888

But that is far from ideal since the MAMP setup I like to use utilizes Apache name-based virtual hosts to allow for there to be one root at:

http://localhost:8888

And then another one based on your machine ID of—for example—MY_MACHINE like this:

http://MY_MACHINE.local:8888

The problem with this and how to solve it.

The problem? Two things.

1. Localhost is Relative: One, since localhost is universally considered a machine’s own loopback address, the actual localhost on a guest OS in VirtualBox would be the loopback of the guest OS itself. When in reality you want the localhost of the host machine. Which is an entirely different machine from a virtualization standpoint.
2. Multicast DNS Broken in VirtualBox: The other issue is that due to the fact that Windows and VirtualBox do not play well together with regards to multicast network packets—let alone MDNS (multicast DNS)—a machine hostname like MY_MACHINE.local:8888 will never be visible to Windows in VirtualBox.

The solution to both of these issues for our purposes is to simply edit the hosts file on the Windows guest OS. The file is located here.

c:\windows\system32\drivers\etc\hosts

And should be edited via a text editor—such as Notepad—run as an administrator.

Since the hosts file user editable when running Windows in VirtualBox, so you can create hostname aliases of your choice. But for this example I would use MY_MACHINE like so.

10.0.2.2    MY_MACHINE
10.0.2.2    MY_MACHINE.local

Doing this, you would be able to connect to the equivalent of the following.

• MY_MACHINE:8888 would be the same as localhost:8888
• MY_MACHINE.local:8888 would be the same as MY_MACHINE.local:8888

Conclusion.

So now you should be able to connect to anything on MY_MACHINE.local:8888 and view it as if it were being viewed from MAMP on your Mac desktop. But in the case of the localhost equivalent of MY_MACHINE:8888 depending on the codebase configuration of whatever you are testing, you might need to temporarily adjust the config files in your local MAMP set to reflect the new MY_MACHINE:8888address since localhost:8888 won’t be reachable.