I am making a local web app. Users will connect through WiFi and all DNS requests result IP of my server. Windows PCs and phones check http://www.msftncsi.com/ncsi.txt for check internet connectivity. So I made a simple text file with that name and they think it is OK. I have problem with Android and iOS smartphones. Specially iOS, It disconnect WiFi if user ignores its alert. I think android phones connect to mtalk.google.com:5228 to check notifications and other things. How can i fool them?
"Basically, it’s the Network connectivity status indicator (NCSI) service that does the trick..."
You can see at: http://www.nextofwindows.com/how-windows-7-knows-my-network-connection-status