Trifork Blog

Posts Tagged ‘WIFI’

Building a Captive Portal – controlling access to the internet from your network

January 15th, 2013 by
(https://blog.trifork.com/2013/01/15/building-a-captive-portal-controlling-access-to-the-internet-from-your-network/)

What is a captive portal?
Wikipedia says: “The captive portal technique forces an HTTP client on a network to see a special web page (usually for authentication purposes) before using the Internet normally. A captive portal turns a Web browser into an authentication device. This is done by intercepting all packets, regardless of address or port, until the user opens a browser and tries to access the Internet.”

Basically, when accessing a network (in most cases a WIFI network), a captive portal will block any traffic (to for instance the internet) as long as the client did not go through a predefined workflow. That workflow begins when the user opens a web browser, and via that same browser the client is required to for instance:

  • authenticate itself
  • accept terms
  • pay fees
  • etc.

In this post, I will show you how you can build this kind of solution for your own network using several open source tools, primarily CoovaChilli.
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