Apparently it is ndpi / deep packet inspection which blocks teamviewer. I found this link, where @filippo_carletti mentions it, thus I would like to learn, how ndpi can be configured to allow teamviewer traffic. May I ask, why ndpi is not configurable in cockpit interface? Generally is it correct to consider packages only available in old webinterface (ex. ndpi or pop3 proxy) are soon to be obsolete? Will the old server manager stay available in general or is it planed to disapear? I am asking, as on one of my nethservers I have a bug, where dns entries can be created but not deleted from cockpit, whereas they can be deleted from old interface.