Ask users to register to gain access to Wi-Fi

Question

I have been scratching my head on how this can be accomplished, we all know that almost all routers have a function for "private" Wi-Fi and a guest Wi-Fi access, the guest Wi-Fi on your router can have a simple password or nothing at all, some routers give you the ability to schedule the access to Wi-Fi like a parental control... well the thing is that instead of assigning a password for the guest Wi-Fi, I'd like to leave it open. The catch is that when they get connected and open a page they have to register or login in order to gain full access to the Internet via the guest Wi-Fi.

I saw this functionality a few years back in Westfield Montgomery, when you open your cell-phone or laptop looking for a hot-spot or free Wi-Fi it shows the mall free Wi-Fi, when opening an app or a browser, the first thing you see is the registration/login page. After you login in or register, you get full access.

I'm wondering how this is done. I would greatly appreciate it if you kindly give me some feedback on this research.

Answer 1

This function is called "Captive Portal". It basically works in the following way:

1. New user connects to AP
2. All traffic of this user (identified by IP or MAC) is redirected to the portal server and access to anything else is blocked by a packet filter firewall
3. After registration/successful login, a dedicated "ALLOW" - Rule is created for the user, allowing the user to bypass the redirection and access the Internet

There are many solutions for captive portals out there. Some Access Points have a captive portal system build in, too (Aruba, Aerohive, UBNT for example).

Regards, Sebastian