Access qnap outside lan

I’m not able to access my library on my QNAP251. If my Roon core is in the same lan then \\Multimedia is working well.
On my second core outside the lan I tried with ddns to connect but failed. Port forwarding on my router is set.
Can someone give me an example of the right path and settings?

Roon only works inside a single subnet.

It is not about roon. I have a 2nd roon subscription running in a different location(home2) and are not able to connect my library with the nas in home1.

this is what i mean.

I am getting what you want to achieve, but I am a bit unsure about the setup.
I understand, you have 2 locations. and want to connect by smb location2 to location1.
If you have setup a ddns, you can’t use the local IP addresses of location1. With ddns you normally get some URL like or (whatever you have set up at the ddns service provider).
That means your smb mount should be established as
Remember, as I wrote before these are example URLs, I just made up. It depends on your ddns provider how your URL looks like.

Also, I’d feel a bit unsafe exposing smb service to the internet. Maybe VPN could also be an option. Several routers offer the option to connect to VPN servers as well.

The connection speed will also depend on the internet upload speed of location1. I have never tried something like this, but could imagine that the performance is not superb.

If I’d be in your position, I’d use a service to mirror the audio files from location1 to location2. I use for example Resilio Sync to backup all my Media files from one NAS to the other. This works also over Internet without having a ddns.
In this scenario location2 will always sync to location1 and the files are local for both cores. But you need sufficient hdd space available to have a copy of your music files in each location.

Thanks Christopher,

I will follow your advise. I have an older QNAP nas somewhere. I will use this unit to set up a mirror solution.