What's the technology inside commercial NAS to give access outside local lan?

Zitat von darrepac

When I bought a WD My CLoud Nas, I just plug it in my LAN with access to internet and I can access my data from the WD web and apps from anywhere outside without doing anything on my router, no port forwarding, no VPN etc

If a WD My cloud NAS does this, then I'm pretty sure I'll NEVER buy one.

Sorry but I don't believe this. No LAN equipment will be able to connect from WAN unless the router is portforwarding some ports to it.

Something needs to be done on the router to permit this.

Unless you plugged it straight to the router via USB and activated the Share (this is me speculating.)

The mechanism is very easy:

• The NAS device connects to a cloud service run by the vendor and gives it access to your local files
• You do not connect to your NAS when you try to access the files but to the vendors cloud service which in turn proxies your connection to the NAS.

To replicate this, you need

• A server on the internet (ceap vps will be enough)
• A process on your NAS to connect to the server (ssh with port forwarding comes to my mind)
• An ssh process on the other device which connects to the server and forwards traffic between the NAS and the other client.

Outgoing traffic usually is not limited, that's the whole thing. NAS conects to cloud service opening a network connection from the inside.