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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
OL-12247-04
Chapter 10 Configuring Web-Based Authentication
Understanding Web-Based Authentication
Host Detection
The switch maintains an IP device tracking table to store information about detected hosts.
Note
By default, the IP device tracking feature is disabled on a switch. You must enable the IP device tracking
feature to use web-based authentication.
For Layer 2 interfaces, web-based authentication detects IP hosts by using these mechanisms:
•
ARP based trigger—ARP redirect ACL allows web-based authentication to detect hosts with a static
IP address or a dynamic IP address.
•
Dynamic ARP inspection
•
DHCP snooping—Web-based authentication is notified when the switch creates a DHCP-binding
entry for the host.
Session Creation
When web-based authentication detects a new host, it creates a session as follows:
•
Reviews the exception list.
If the host IP is included in the exception list, the policy from the exception list entry is applied, and
the session is established.
•
Reviews for authorization bypass
If the host IP is not on the exception list, web-based authentication sends a nonresponsive-host
(NRH) request to the server.
If the server response is
access accepted
, authorization is bypassed for this host. The session is
established.
•
Sets up the HTTP intercept ACL
If the server response to the NRH request is
access rejected
,
the HTTP intercept ACL is activated,
and the session waits for HTTP traffic from the host.
Authentication Process
When you enable web-based authentication, these events occur:
•
The user initiates an HTTP session.
•
The HTTP traffic is intercepted, and authorization is initiated. The switch sends the login page to
the user. The user enters a username and password, and the switch sends the entries to the
authentication server.
•
If the authentication succeeds, the switch downloads and activates the user’s access policy from the
authentication server. The login success page is sent to the user.
•
If the authentication fails, the switch sends the login fail page. The user retries the login. If the
maximum number of attempts fails, the switch sends the login expired page, and the host is placed
in a watch list. After the watch list times out, the user can retry the authentication process.