85
{
If a user contained in the packet does not exist on the access device, the access device
informs the portal authentication server to delete the user.
{
If the user does not appear in any synchronization packet within a synchronization detection
interval, the access device determines the user does not exist on the server and logs the
user out.
Portal Web server
A portal Web server pushes the Web authentication page to authentication clients and forwards user
authentication information (username and password) to the portal authentication server.
The portal authentication server and the portal Web server are usually the same device, but they can
also be separate devices.
Redirection URL parameters
This feature configure the parameters to be carried in the redirection URL. Commonly required
parameters include the user IP address, user MAC address, and the URL that the user originally
visits.
After you configure the URL parameters, the access device sends the portal Web server URL with
these parameters to portal users. Assume that the URL of a portal Web server is
http://www.test.com/portal, the originally visited URL of the user whose IP address 1.1.1.1 is
http://www/abc.com/welcome, and you configure the user IP address and original URL parameters.
Then, the access device sends to the user whose IP address is 1.1.1.1 the URL
http://www.test.com/portal?userip=1.1.1.1&userurl=http://www.abc.com/welcome.
Portal Web server detection
A portal authentication process cannot complete if the communication between the access device
and the portal Web server is broken. To address this problem, you can enable portal Web server
detection on the access device.
With the portal Web server detection feature, the access device simulates a Web access process to
initiate a TCP connection to the portal Web server. If the TCP connection can be established
successfully, the access device considers the detection successful, and the portal Web server is
reachable. Otherwise, it considers the detection to have failed. Portal authentication status on
interfaces of the access device does not affect the portal Web server detection feature.
You can configure the following detection parameters:
•
Detection
interval
—Interval at which the device detects the server reachability.
•
Maximum number of consecutive failures
—If the number of consecutive detection failures
reaches this value, the access device considers that the portal Web server is unreachable.
You can configure the device to take one or more of the following actions when the server
reachability status changes:
•
Sending a trap message to the NMS. The trap message contains the name and current state of
the portal Web server.
•
Sending a log message, which contains the name, the current state, and the original state of the
portal Web server.
Local portal Web server
Using this feature, the access device also acts as the portal Web server and the portal authentication
server to perform local portal authentication on portal users. In this case, the portal system consists
of only three components: authentication client, access device, and AAA server.
