1-6Re-DHCP authentication processFigure 1-3 Re-DHCP authentication processAuthentication/accounting serverAuthenticationclient Portal server Access device6) AuthenticationsucceedsSecuritypolicy server12) Security authentication13) Authorization7) The user obtainsa new IP address8) Discover user IP change10) Notify the user oflogin success9) Detect user IP change11) IP changeacknowledgementTimer1) Initiate a connection2) CHAP authentication3) Authentication request5) Authenticationacknowledgement4) RADIUSauthenticationThe re-DHCP authentication process is as follows:Step 1 through step 6 are the same as those in the direct authentication/Layer 3 portal authenticationprocess.7) After receiving an authentication acknowledgment message, the authentication client obtains anew public IP address through DHCP and notifies the portal server that it has obtained a public IPaddress.8) The portal server notifies the access device that the authentication client has obtained a new publicIP address.9) Detecting the change of the IP address by examining ARP packets received, the access devicenotifies the portal server of the change.10) The portal server notifies the authentication client of logon success.11) The portal server sends a user IP address change acknowledgment message to the accessdevice.With extended portal functions, the process includes two additional steps:12) The security policy server exchanges security authentication information with the client to checkwhether the authentication client meets the security requirements.13) The security policy server authorizes the user to access unrestricted resources based on thesecurity configuration for the user. The authorization information is stored on the access deviceand used by the access device to take control of user access.Portal Configuration Task ListComplete these tasks to configure portal authentication:
