Configuring USB-Connected HDD for FTP Sharing via NordVPN Dedicated IP on AC86U

[Wobbo]

I have an AC86U 386.12_4. I have OpenVPN with a static NordVPN IP Dedicated address, and an HDD connected to the router via USB. I want to share the HDD via FTP using my Dedicated IP, but currently, I can only access it through my router's WAN Automatic IP. Despite extensive searching, I'm unable to find a compatible solution. The information available seems to only address configurations for VPN servers, general VPN client setups, or NAT-related issues.

How can I configure my USB-connected HDD for FTP sharing using my NordVPN IP Dedicated address?

 

[ColinTaylor]

How can I configure my USB-connected HDD for FTP sharing using my NordVPN IP Dedicated address?

It's likely that this is not possible. FTP is unusual in that it requires separate control and data channels and was never intended to work over NAT. As such it requires "helper" support on the router and hole punching for the data channel on the firewall. The firewall in this case is administered by NordVPN, and I doubt they provide user-customizable firewall rules.

 

[Wobbo]

Thank you for your explanation about the complexities of FTP with NAT and VPN services. I understand the challenges you describe. However, in my situation, I do not intend to use NAT. My goal is to provide direct FTP access to my USB-HDD via my router, which is connected to NordVPN through a Dedicated IP. This Dedicated IP offers a unique, personal IP address, which should mean that the typical issues with NAT and FTP are not applicable. Would it be possible to configure the FTP server to be accessible only through this Dedicated IP, without the involvement of NAT? Are there specific settings on the AC86U router or within the NordVPN configuration that could facilitate this?

 

[ColinTaylor]

Even if NordVPN are assigning you a dedicated public IP address you still have NAT unless they are providing some sort of IP passthrough, which I think is unlikely.

You can check this by looking at the router's VPN - Status page. What do you see for "Local IP"? Is this a public address, or a private address like 10.x.y.z?

EDIT:
Looking at NordVPN's website it looks like their dedicated IP is just the same as their normal service apart from the IP of their exit node not being shared with any of their other customers. So NAT would still be present.

Reading more, NordVPN doesn't support port forwarding for incoming connections so this makes it unsuitable for remote access to most servers, including FTP. If you really need remote access to the FTP server it would be better to enable the router's VPN server and access it through that.