Captive Portal
Okapi > Miscellaneous > Captive Portal

 

Introduction

 Okapi's captive portal technique forces an HTTP client on a network to see a special web page for authentication purposes before using the Internet normally. This is done by intercepting all packets, regardless of address or port, until the user opens a browser and tries to access the Internet. At that time the browser is redirected to a web page requires authentication.

 

Network Diagram

 

 Configuration

!

ip domain-lookup

ip name-server 10.20.50.50

ip name-server 8.8.8.8

! DNS servers which will be allowed for dns queries of unauthenticated clients

access-list 101 sequence 10 permit all any host 192.168.1.1

!  access-list is used, so that communication from authentication server to gateway is allowed

!

configure captive_portal

  inbound interface FastEthernet 1

  listen-address 192.168.1.1

  ! listen-address is used internally by NoCat to bind itself to an inet socket, the default

  ! port is 5280, which can also be changed with the listen-address command

 

  allow acl 101

  authentication ldap

  ldap server host 192.168.1.3

  ldap server baseDN dc=your,dc=company,dc=in

  ! LDAP authentication configuration

!

!

interface FastEthernet 1

  ip address 192.168.1.1/16

  no shutdown

 

 

This is the basic configuration, which demonstrates the use of captive portal in a private lan. The users will be redirectedto a web page when they try toaccess the internet using a web browser.The users will have to use their LDAP username password to authenticate, because we have used LDAP authentication protocol.