Well I have in my Pi-Hole blocked many URLs from google. One of the URLs is the Android connection test. “to make sure your phone is on line” To circumvent my phone saying it is not on line I followed this guide Self-hosting the WiFi Connectivity Check for Android
So basicly I created a file called 204.php on my internal web server I use for testing stuff that contains
<?php
http_response_code(204);
exit(); ?>
I put it in my /var/www/htdoc directory and added the following to my httpd.conf file
NameVirtualHost *:80
<VirtualHost *:80>
ServerName connectivitycheck.gstatic.com
RedirectMatch 204 .*
</VirtualHost>
The thing is I would never have known about this URL to be blocked if they did not make so many requests. When I look at the stats for my Pi-Hole it is the top requested domain name, in the last 24 hours the phone has done 5512 lookups for the domain. I keep an eye on the stats on my pi-hole, and when there is a unrecognized URL hit that often I start to look into it, most of the time they get blocked. If google was not so greeded for the data and spamming it so often I might never have known the requests were being made, and it would have flown under the radar, but since it the #1 requested URL on my network it looked suspicious to me. So I looked into it, and blocked it, and setup a work around to it.
Now my phone thinks it is getting a response back from google and accepts that it is online and will not block apps from connecting to the internet. But the surprise is how often it checks, Here from the logs
192.168.42.228 - - [09/May/2021:18:17:48 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:17:57 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:18:18 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:18:21 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:18:30 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:21:40 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:22:01 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:22:04 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:23:37 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:24:22 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:24:25 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:25:10 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:25:31 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:25:40 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:26:02 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:27:35 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:27:38 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:27:47 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:28:32 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:34:53 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:34:56 -0400] "GET /generate_204 HTTP/1.1" 204 -
192.168.42.228 - - [09/May/2021:18:35:05 -0400] "GET /generate_204 HTTP/1.1" 204 -
as you can see it checks several times a minute, I don’t think people go in and out of WiFi that fast, but google really must think they need to know your IP address.
So now I block the requests from going out to google, I host it on my own intranet web server.
