I recently purchased a network attached storage for personal file storage and would like my family members to store files on the device from their computers as a remote backup.
I'd like to secure the port that's used to sync files so that only their computers will have access. The solution should be easy for them to implement and use on a daily basis. I believe that backing up files should be easy, seamless, and automatic. Most of these files are media (pictures, home movies, etc). Backing up files to an alternative cloud based system is not an option.
My problem is that each of these computers have dynamic IP addresses so it's not as simple as setting up the firewall to only allow from a handful of IP addresses. They don't change very often, but they do change.
I'm running a DDWRT-based (standard) router connected to the NAS so I can add custom firewall rules if needed or run a script. For the sake of this question, the port that the service is running on is TCP 5678. What's the best solution to secure access to the NAS?
- Setup a VPN (not very convenient for users)
- Setup firewall rules based on the entire network of the clients ISP
- Setup firewall rules and update the IP address using a dynamic DNS service and a script that runs periodically
I've created a simple diagram to show my setup.