Http Connectivitycheck Gstatic Com Generate_204 Porque

Perchance this seems likely to be a problem connecting to Google servers (captive portal server)
not the browser configured captive portal login
y’all seem to be refering to in your post.

(Sometime since Lollipop (v.1+)) When connected to networks (especially Wi-Fi networks), android system checks if there is an active net connection past perfoming checks on certain pre-divers URLs belonging to Google servers. If it fails, at that place’ll be an exclamation mark on the Wi-Fi signal icon and a “Connected, no net” notification is shown
(even though you can access other websites and the internet is upwards an running)
so information technology may be a temporary trouble with connectivity to that specific URL:

Android tries to attain a file named
generate_204
on one of the Google servers and if there is no positive response, information technology means that there is no connection to the net, and notification is generated as well, the detection url differs between dissimilar Android versions.

• clients3.google.com/generate_204 check (kitkat)

• connectivitycheck.gstatic.com/generate_204 (marshmallow)

It seems that google has changed the captive portal detection on recent versions of android e.g oreo.

looks like google now checks for both a
generate_204
on both
connectivitycheck.gstatic.com
and a
gen_204
on
www.google.com.

Once more is a trouble on its ain esp in regions where admission to google services is blocked. This
answer
notwithstanding explains well how to bypass such and you lot brand accept a look at it.

A chunk of information has been extracted from this discussion.

Based on this yous have some options to bypass this:

1. Irresolute captive portal server

   • Install a last app alternatively these commands can as well be run via the
     adb vanquish.

   • Open the terminal app and run
     su.

   • Run
     settings get global captive_portal_server. This will evidence the electric current captive portal server. A “null” reply is usually the default.

   • Run
     settings put global captive_portal_server YOUR_SERVER_ADDRESS. You lot can add together google.com as the captive portal server,
     i.e settings put global captive_portal_server google.com.

   • Run
     go out
     in one case to leave from su, then exit ane more time to close the final.

   • Reboot the Android device. Will non work without a reboot.

---

2. Disabling convict portal

• Since the culprit is a method
  isCaptivePortal()
  which admission
  clients3.google.com/generate_204
  to test if a connectedness is deemed “usable”. The page, every bit its name suggest, is designed to e’er render a
  HTTP 204
  status code. Based on this you have a couple options:

i. Kill
isCaptivePortal()
completely

• with adb set, run
  adb beat su -c "settings put global captive_portal_detection_enabled 0"
  (Android 7.1+) or using
  adb shell su -c "settings put global captive_portal_mode 0"

Notation:
The downward side is that isCaptivePortal() is actually useful to detect for example when a WiFi network requires login. If the request to the 204 page gets redirected to a login page (non a 204), the system will understand and display the exclamation mark as intended.

2. Alter the target of
isCaptivePortal()

• another workaround is replacing the Google host with a host that is accessible within the specific region. This host should also be returning
  204
  every time
  /generate_204
  is accessed.

  i.east
  adb shell su -c "settings put global captive_portal_server {alternate_host} "

---

3. Using hosts

   • You tin edit
     hosts
     to block the convict portal detection url thus bypassing the sending of the requests to captive portal server.

---

Why Linux and Windows connect with no problems?

As yous mentioned in your post that this seems to be Android specific, indeed the above discussion highlights that. The reason is that for those devices (Linux and Windows) the mechanism of connection is completely unlike.

These devices won’t need to connect to Google servers to kickoff detect if an internet is active.