I wrote a DNS server in PHP, and I am running it on a Raspberry Pi (terminal) to use it as a Captive Portal.
I am fully capable of redirecting all DNS requests.
I connect the Raspberry Pi to my router (Ethernet cable) and assign the IP address of the Raspberry Pi to the primary DNS of my router.
I am using a MySQL database to save authenticated devices in order to be able to know who can navigate and who can not.
Everything is working fine.
My problem: when a device connects to my Wi-Fi hotspot I would like the Captive Portal Splash Screen to automatically popup in order to allow the user to authenticate.
On Android it is working: I only had to redirect requests for "clients3.google.com" to the Raspberry Pi IP address and create the "generate_204" file in my web server (Apache) root folder (/var/www).
On iOS it is NOT working: the iOS Captive Portal Splash Screen is not opening when the device connect to the Wi-Fi hotspot, and I can not find enough documentation on the web in order to solve it.
How do I open the iOS Captive Portal Splash Screen when the device connects to my Wi-Fi hotspot?