[Deviant96]

So. I have a server and port forwarder (PFconfig).

First.
1. I installed the PFConfig. Done.
2. Run it. Done.
3. I fill the username and password both with "admin". Done.
4. Register PFConfig. Done.
5. Select the router: I have TPLink TD-8817. But, in the PFConfig only TD-8810 (and the other). I updated the router list. Still can't get 8817.
6. I forwarded SAMP. Done.
7. Clicked "Update Router". Done.

Second.
1. Extracted the server files. Done.
2. Running samp-server.exe. Done.

There it is. My friend still can't enter.