You can use the web-based authentication feature to authenticate end users on host systems that do not run the IEEE 802.1X supplicant. You can configure the web-based authentication feature on Layer 2 and Layer 3 interfaces.
When a user initiates an HTTP session, the web-based authentication feature intercepts ingress HTTP packets from the host and sends an HTML login page to the user. The user keys in their credentials, which the web-based authentication feature sends to the AAA server for authentication. If the authentication succeeds, web-based authentication sends a Login-Successful HTML page to the host and applies the access policies returned by the AAA server.
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/webauth.html#wp1067205