Hey friend,

At least from a big picture view three things need to be true:

1. The nested VM (Windows) is listening on it’s interface for external RDP traffic, meaning it is configured to accept outside connections.
2. The host OS (CentOS) is forwarding traffic to the relevant port on the VM’s IP.
3. Both the host OS and the guest OS (Windows and CentOS) need to be allowing the port through their firewall. At least on CentOS this is open by default unless you close it, not sure about Windows.

Now I can’t tell you step by step how to do this, and maybe someone else can, but my hope here is that by laying this out you can start to identify where the problem exists. If it’s not working, you know one of the above items is not configured as stated. With that, you can go down the list and make sure that you check off each one. Perhaps it’s true that you think everything is configured for this to be working, but there is something not working as you intended it to with your configuration.

To test connectivity, I like to use telnet. Here’s an example of what that looks like:

[jarland@desktop ~]$ telnet jarland.me 80
Trying 64.111.125.207...
Connected to jarland.me.
Escape character is '^]'.

Now let’s say your Windows installation has an internal IP address of 192.168.1.1, and let’s say the RDP port is 40 (random number). You might test it within CentOS like this:

telnet 192.168.1.1 40

If that fails, then you know the answer sits somewhere around #1 above, because you’ve taken the forwarding part out of the equation.

Hope that helps you to move in the right direction at least :)

Jarland