So I have Volumio x86 installed on a little netbook and working fine, web access works flawlessly. I have installed the Volumio Spotify Connect2 plugin. When I start Spotify on my Ubuntu 16 laptop (either desktop app or the web player), the volumio device does not show up in my list of Spotify Connect devices. However, on my girl friend’s laptop (running Windows 10 with Eset Internet Security firewall) the volumio device is visible and thus can be selected.
When I completely disable the UFW firewall on my ubuntu laptop, the volumio device shuddenly shows up. So this is obviously a firewall issue. The question then: which port(s) do I have to open on my ubuntu laptop for Spotify Connect to work?
Note: I have no problem connection to other Spotify sessions with UFW enable on other devices be they running ubuntu, Windows or Android.