Depends on your modem, from here.
But the way to fix it is just turn on DMZ, some modems call it "Apply device to Public ip".
Most modems settings can be accessed through typing your IP into the URL bar up top on your Browser. To find your IP, just search whatsmyip and then just click the link at the top, it will show you your IP. Copy paste it onto the top, enter. That should lead youto your modem settings. I'm not particularily sure about if this works for all modems. If this doesn't work, google it, google your modem model and how to activate DMZ, or apply a device to a public ip. When you do do this, repair your IP and then you should be done.
This works for me. I do it all the time.
spam lol
Well it I'm not sure if it will work for all the people, theres like 1 billion types of modems.
shut up
What DMZ does is open all ports on your router.
This does, indeed, fix R issues because a person who is an R simply has a port that your router does not allow.
However, with all ports open, your computer is at an EXTREME risk with security.
Though most people ignore this..
I know that, but thats why you don't start any conflict with epic hackers. Lol.