In the Preferences / Tools / Network / Advanced window, what is the purpose of the "Force local IP" and "Force local port"?

What are these ports? My windows are empty. Should I put data there?

I have been trying for 2 weeks, but can't download a damn thing.
The search brings up files, but nothing happens, yet my modem lights are going crazy.


Also, my cursor disappears when I change box sizes, and the "GO" button is not visible?

Can someone explain?