I have a working access point on a rspbi, works perfectly with my captive portal on ios and os x based machines.
But android does not popup a captive portal, and I can see the requests for clients3.google.com
The way I do the captive portal is by redirecting port 53 (udp) to my apache server, and there display the login page for the access point.
Any ideas why there is no automatic popup? I already checked the chromium project page and it looks like I did everything right.
Thanks.
The requests for client3.google.com need to be redirected to the login page (portal page). Then Android will think it needs to login to the network (captive portal) in order to gain internet access.
As long as Android receives the expected success message back from its requests to client3.google.com, it will assume it is not behind a captive portal, and not prompt you to login.
See also: https://serverfault.com/questions/679393/captive-portal-popups-the-definitive-guide/
