@greichelt On your fog server itself, there is a config file /etc/resolv.conf that file should list your name servers (DNS servers) used for the fog server to do name lookups. A quick google-fu will show you the parameters needed for that file. Typically on ubuntu that file is managed by the network manager application. Just be aware of that because it may overwrite any settings you add. For the network manager application that is typically an application on the tool tray that deals with network configuration (sorry I’m a rhel guy, so I can’t give exact instructions for ubuntu).