Sonoma FTP file sharing to users not on same network

You can technically enable FTP on macOS Sonoma, but Apple discontinued its native FTP server years ago — and for good reason. FTP sends both usernames and passwords in plain text, making it completely insecure across the internet.

The simplest and safest route is to use SFTP. macOS already runs an SSH server that you can enable in System Settings → General → Sharing → Remote Login. Once that’s turned on, you can connect from Germany using any SFTP client (like Transmit, ForkLift, or even Finder with “sftp://your.public.ip”). You’ll just need to forward port 22 on your router to your Mac Studio and ideally secure access with a strong password or, preferably, SSH keys* If your public IP changes, using a dynamic DNS service (like DuckDNS or No-IP) keeps it reachable.

Guerin wrote:

I think I understand the first part, as I looked into that. But could you "translate" that second part.

The "second part" is about how you currently get your Internet service. Typically, most consumer-grade service is provided with a dynamic WAN-side IP address. This address changes over time and is controlled by the ISP. On the other hand, a business-grade service typically comes with a static WAN-side IP address. With the latter, the IP address of the router (as seen from the Internet) does not change. This is what you would want for users to connect to your router.

With a dynamic address, you would constantly need to let users know what the current IP address is. This is tedious at best. This is where Dynamic DNS (DDNS) comes into play. This service keeps track of the changing IP address and presents to the user a pseudo static one. DuckDNS and No-IP are two providers of this service.

you will likely have an easier time by using some cloud setup on both devices such as icloud, onedrive, googledrive or dropbox or...

then your personal computer will not be required to be public access on the internet with a possible requirement of a static ip address which some isp would require extra payment for.