Which of these web authentication scenarios uses the Cisco ISE Policy Node to authenticate users based on username and password?

The scenario that uses the Cisco ISE Policy Node to authenticate users based on username and password is Central WebAuth. In this configuration, the authentication process involves redirecting users to a Cisco ISE policy node where the credentials they enter are validated against a user store. This allows for a centralized approach to authentication, leveraging Cisco's Identity Services Engine capabilities to apply various policy rules, incorporate profiling, and enforce security requirements.

Central WebAuth typically requires the user to enter their username and password on a web portal. Once these credentials are submitted, the process of authentication is managed through the ISE, which can handle user identities more effectively and enforce granular access controls based on policies. This centralization simplifies managing user access and increases security as all authentication takes place through the centralized ISE system.

In contrast, Local WebAuth relies on local device capabilities without the involvement of an external policy node like Cisco ISE for managing user credentials. Device Registration is not focused on user authentication in the same manner, as it pertains to the onboarding of devices rather than individual user credentials. 802.1X involves a different mode of authentication using Extensible Authentication Protocol (EAP) which typically doesn't focus solely on username and password input through a web interface.