Port forwarding Router -> Windows -> VirtualBox ?

Question

Network administration

There is the following configuration of the
Router, the Internet is connected to it.
There is a computer on which windows 8 is
installed On the computer is VirtualBox
In VirtualBox is Debian
From Windows to VirtualBox, I threw the ports, everything is ok.
Those. if you connect to 1 network of the router via IP, then ok, it allows you to go to the virtual machine.
If you connect to the external IP of the router, then it's not ok :(
The router also has port forwarding
Router 8081 -> 80 (192.168.0.161)
Windows 80 (192.168.0.161) -> 80 (10.0.2.15)
Where or how?

Answer 1

The reason turned out to be this.
1. There is a firewall on the router, so it was necessary to allow ports there.
2. On the virtual machine, I did it through the Bridge so that the virtual machine had its own route IP
3. It refuses, you can’t hammer yourself on an external IP; I tried it from outside and the norms were correct :)

Answer 2

There can be many reasons.
For example:
1 reason - the provider does not allow requests from outside to your network.
2nd reason - forwarding on the router is not properly configured
3rd reason (and I'm almost sure that it's all about it) - forwarding is not configured on Windows 8. As you know, the system is not a server one. You need to enable the service, if I'm not mistaken, the name is "Routing and Remote Access" .. Or something like that.
Reason 4 - the firewall on Windows interferes. Disable at the time of setting
5 reason - antivirus can interfere
In general, there is such a utility - tcpdump. In Linux it is present, in Windows it can be downloaded and installed for free.
Put it on and start troubleshooting, trying to figure out where the packets go and where they don't.