title: Captive portal without internet on Android
body: <p>Good day.
  I need Captive Portal on the WiFi hotspot that will work without internet and popup a notification or open a login page automatically.
  I am using Mikrotik with RouterOS 6.27.
  I created hotspot and then added a RegExp in DNS like </p>
  
  <p>.* = HOTSPOT_IP_ADDRESS</p>
  
  <p>It works fine in Windows and iOS since their captive portal detection is based on getting the response from some website. Afaik - any response.
  But for Android it must be some special response, with empty content or status code 204  - I am still not sure.</p>
  
  <p>I tried to emulate google pages which give 204 or empty response and did redirection to my server with this emulation pages but it did not help Android to show notification.</p>
  
  <p>So I need help to make captive portal notification in Android without internet.</p>
  
  <p>Thanks.</p>