Connecting to Q'Center behind NAT

[derekzeanah]

So here's my situation:

• 3 NAS devices on local network
• All local QNAPs connect to Q'center cleanly.
• Want to monitor a remote QNAP device without leaving a VPN open or opening a port in the remote firewall for compliance reasons. So I'm going to allow it through the local firewall.
• Configured remote QNAP with DDNS hostname
• Created a firewall rule to allow connections (ports 443, 873, and 8899) from that DDNS hostname.
• Connected from site via 443 - it works.
• Added a registration code in Q'Center
• Installed and ran the connect to Qcenter app. It connected and installed the agent.
• Now, when running the agent to try and connect I get the error message "Failed to Add."
• I've tried changes like connecting with/without https, using 8080 instead of 443 (with and without https), changing the code to something shorter and just lower case. It's always "Failed to Add," or can't connect if I mismatch the https:// and port number.

I'm at a loss here. I feel like the app should be working so there's something I'm doing incorrectly, but I have no idea what that might be.

Firewall logs show it is being allowed through (as suggested by direct connections).

[storageman]

Looks so simple here
https://www.qnap.com/en/how-to/tutorial ... h-q-center

I assume you are not confusing it by using uPnP and NAT