Investigate whether Android devices can connect via internet when no internet access is detected
During a partial internet shutdown where a national network is disconnected from the internet but routing still works within the national network, Android devices may report that they don't have internet access because they can't fetch the URL that's used for detecting internet access (see https://stackoverflow.com/questions/33431931/how-does-android-know-if-the-wifi-connection-has-internet-access-or-not/39475588#39475588).
In this situation it would be useful to know whether an app can still route traffic to addresses on the national network. We might be able to simulate this situation by blocking access to the captive portal detection URL and perhaps also blocking DNS.