I wanted to access my NAS remotely using Airport Extreme

I presume you refers to Tesserax although you don't make that clear.

What model is the Buffalo exactly?

Many NAS have built in remote access methods that are easier and quicker to setup than using the standard method..

The problem for remote access is that,

1. You need a public IP that is static from your ISP or dyndns account. This is not so easy to setup with Apple airports.

2. Using a Mac to a non-apple NAS makes a big question of what protocol you will use.. I therefore cannot answer the question without reading the Buffalo documentation.

3. IMHO if you want to use a Mac and Apple Airport, then do it the Apple way.. ie BTMM and plug a USB drive to the Airport.. that is going to be hugely easier than reinventing the wheel. Transfer all the files you want remote access to from the NAS to the USB drive.

Chapter 3 in the User Manual for this NAS covers remote access using the WebAccess program. Did you go through that and it wasn't successful? ... or is your goal to use a different access method for your iOS devices?

If it is different from using WebAccess, then the following, as a minimum, will be required:

• Configure the NAS with a static local IP address.
• Open ports on the AirPort base station to allow access to the NAS from a remote location. Alternatively, although not recommended, is to place the NAS in a DMZ. (Note: As mentioned by LaPastenague, using BtMM would be far simpler than either of these methods.)
• Use an app, like FileBrowser, on the iOS device to access files on the NAS.

I can access it if I am within my network but my problem is I can't do it if I'm out of my network. I am using the App from Buffalo and some File Browser with ease.

Yes, we understand that you want to access the NAS from a remote location.

I think my problem is the opening of ports? Or I need to do something more? Is it ok to post a screenshot here of the settings that I've done for me to be specific if I've done something wrong?

Opening ports is one of the requirements to access remotely. Yes, you can post a screenshot as that would help us understand what the current configuration is. However, we may not be able to help you with the NAS set up itself as this is an Apple networking forum ... but we can try.

"Double NAT." Here would be your first problem! This is telling us that your AirPort Extreme is in series with another router upstream of it. In this case the Extreme need to be reconfigured as a bridge, that is, Router Mode = Off (Bridge Mode) and port mapping must be done on that upstream router, NOT at the Extreme.

Well, you are kinda stuck then. There is another router or gateway device at that other end of the wall connection. That is where port mapping has to take place. So, unless you have access to that other device, there is not much else you can do here ... except using BtMM.

You're very welcome! I'm sorry that I couldn't help you resolve your networking issue.

Try teamviewer to a computer in your network..

You cannot access the NAS directly but via remote desktop to the computer it is sometimes possible to do it.

The statement that you had a public IP was wrong..

I have a Public IP Address and my problem now is how to set it up.

You cannot access a system from outside in this kind of setup.. you do not have an internet routable address.

So one solution is to use a 3g or 4g modem/router with a public IP. Or a different ISP that does offer routable public addresses. Make very sure though before you buy it is truly public address.. many companies using 3G wireless for internet only give out private addresses. And charge a lot more for public IP.

But TeamViewer could still allow you to access your computer remotely.. and then access the NAS.. the speed might be horrendously slow because you are sharing the network with multiple users.. also the ports may already be allocated.

If there are files you need when you travel the best idea is to load them to cloud storage.. or carry files in a 2.5" USB drive.. which are cheap and light-weight plus self powered on any newer computer with a charge USB port.

It totally depends on the setup of the router you have no access to.. so we cannot give you a method..

Try it and great if it works.. otherwise you must use a different method of accessing files on the move.