The following lines were added (+) and removed (-):
SQUID PROXY:Older network engineers might refer to a Captive Portal (a contemporary term) as something else, such as a Squid Proxy. This is because earlier examples were often created using Squid and Apache. Squid is a caching and forwarding HTTP web proxy. Squid Access Control Lists are one way to access to a network or Internet from a network.Components of a typical Captive Portal# access controller# radius server (only for user authentication installations)# radius client and framework (depending on radius)# backend database (only for user authentication, and/or possibly logging facility)# web server and possibly web application server or proxy serverWhen a client connects to an open WIFI network, an IP address is assigned and the web browser request is intercepted then redirected to the captive portal page. On linux iptable rules might be used to restrict access so that only a web client can access only the captive portal page no matter what host or IP it is attempting to contact.From there other components get involved, such as password authentication via radius or by a user simply agreeing to terms and conditions thus eliminating the need for radius and a user database.