Portal Authentication Process - HP 12500 Series Configuration Manual

In re-DHCP authentication and cross-subnet authentication mode, the client's IP address is used for client
identification. After a client passes authentication, the access device generates an access control list (ACL)
for the client based on the client's IP address to permit packets from the client to go through the access
port. Because no Layer 3 devices are present between the authentication clients and the access device in
re-DHCP authentication, the access device can directly learn the MAC addresses of the clients, and thus
can control user packet forwarding in a more granular way by also using the learnt MAC addresses.

Portal authentication process

Direct authentication process is the same as cross-subnet authentication process. Re-DHCP authentication
has a different process because of the presence of two address allocation procedures.
Direct authentication/cross-subnet authentication process (with CHAP/PAP authentication)
Figure 36 Direct authentication/cross-subnet portal authentication process
The direct authentication/cross-subnet authentication takes the following procedure:
An authentication client initiates authentication by sending an HTTP request. When the HTTP
1.
packet arrives at the access device, the access device allows it to pass if it is destined for the portal
server or a predefined free website, or redirects it to the portal server if it is destined for other
websites. The portal server pushes a Web authentication page to the user and the user enters the
username and password.
The portal server and the access device exchange Challenge Handshake Authentication Protocol
2.
(CHAP) messages. For Password Authentication Protocol (PAP) authentication, this step is skipped.
The portal server assembles the username and password into an authentication request message
3.
and sends it to the access device. Meanwhile, the portal server starts a timer to wait for an
authentication acknowledgment message.
The access device and the RADIUS server exchange RADIUS packets to authenticate the user.
4.
The access device sends an authentication reply to the portal server.
5.
The portal server sends an authentication success message to the authentication client to notify it of
6.
logon success.
The portal server sends an authentication reply acknowledgment message to the access device.
7.
With extended portal functions, the process includes additional steps:
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