not only extension but the map chart needs an internet access if you want to show geografic elements in your map (you can do this without also but it's not very nice).
Maybe all other visualizations like web pages, links to the internet or datas from internet needs an access.
But for security restricition, you can operate a sense enterprise envoriment without internet access.
Thank you all for your valuable inputs.
However, If you refer the minimum system requirements in below URL, you get something like INTERNET PROTOCOL - IPV4
Another clue is that when I removed the internet connection form the server (after installing QS), QS hub did not work after few days. There were few service which ware down.
Anybody has any view on above ?
I have noticed that services are not going up after Qlik Sense server reboot if there is not any internet connection available.
Qlik Sense requires also internet connection during installing of application. It uses the OCSP protocal for something and connects to Akamai somewhere. It also refuses to install if there is certain Windows service packs installed.
I don't want to give any internet connection in server environment for the application during the installing or during running it or in server boot.