Can't reach Octoprint from the internet (IPv6, DS Lite)



first of all, I'm not even sure if this is a problem caused by Octoprint. But maybe someone here had a similar issue and was abel to fix it.

I downoaded the latest version of OctoPi (0.14) and also updated to the latest version of Octoprint (1.3.8). I connected the RPi 3 to the local WiFi by adding the needed information to /boot/octoprint-network.txt and set up everything else (Authentification on the website and haproxy) and I am able to connect to the octoprint server via my local IPv4. (everything including the webcam stream is working. but I havn't connected a printer yet, because it is still WIP)
To make my Printer accessable from the Internet, I configured a free domain name from which gets updated by script run by cron on the Pi. As my ISP only provides me with a DualStack Lite connection I need to use the IPv6 Address of the OctoPi to access it from the internet. I defined the eqivalent of portforwarding in my router for the IPv6 adress of the Pi. I allowed the ports 80 and 443 (80 only for testing) and ICMP Messages.
From within the same network I am now able to not access the website of Octoprint via the Pi's IPv4 and IPv6 but also via the corresponding subdomain from

What is the problem?
The Problem now is, that this is not possible from outside my network. Neither the current IPv6 of the Pi nor the assigned subdomain lets me access the Server.

What did you already try to solve it?

  • I checked and rechecked the settings in my router as this seems to me like a router problem. But there is not really much to go on, as the "forwarding" of the IPv6 is a simple entry. The same configuration already worked for me with another webserver.
  • checked hproxy.cfg for errors an right configuration but couldnt find anything. (I configured that HTTP authentification sould not ask for a username and password, if the server is acessed by an IPv4 starting with 192.168.x.x.This also workes as expected) But this could be where I'm missing something, as I have never used haproxy before. Maybe there is a directive that blockes access attempts which are not originating from the local network?

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, octoprint.log, serial.log or output on terminal tab, ...)
As I am currently not at home I cannot acces these logs right now, but if they should be necessary I will add them as soon as I can access them. If you need any further information, dont hesitate to ask.

Thanks for your help in advance.