Hi! My problem is that whenever I try to connect and play with someone over the Internet, I get an error code. I Googled it and followed the instructions listed on Nintendo's website. I had to go in settings on my 3DS and type in the IP address and other things that were on my computer.
I did all of that, but then it said I had to enable my DMZ. I wasn't sure what that meant so I Googled it and people say it's dangerous because it leaves your network vulnerable to hackers. So I tried port forwarding, which is another, less dangerous way but that didn't work either.

Here is the link that I used for help: http://en-americas-support.nintendo.com/app/answers/detail/a_id/12471/p/430.

It says to "forward UDP ports one through 65535". The options I have are "Inbound port" and "Private port", so I put one number in each one. It didn't give me a "through" option.  I have a Belkin router.

Does anyone know how to fix this or any other solutions that could work?? It's just so frustrating because I can't go to anyone's town or have anyone visit. :/ Thanks!!

Placing your 3DS through DMZ is actually the preferred method and is safe for it unlike a computer. Your 3DS will need to have a manual IP address assigned, so you won't have re-input the different IP address for DMZ each time. If you aren't sure how to do this, let me know and I'll be glad to walk you through it. You'll need to post your Belkin router model number.