What template should an Okta Administrator use to configure a custom ASP.net application that requires federation?

The WS-Fed template app is specifically designed for applications that utilize the WS-Federation protocol, which is commonly used in ASP.NET applications that need to authenticate users in a federated manner. This template allows for seamless integration with Microsoft-based identity solutions and supports federated single sign-on between multiple identity providers.

Using the WS-Fed template is essential for ensuring that authentication requests are sent in the expected format and that the application can communicate with the identity provider effectively. This is particularly crucial for applications that require the security and capabilities offered by WS-Federation, such as claims-based authentication.

In contrast, the other templates serve different purposes: the Secure web authentication (SWA) template is used for applications that do not support single sign-on protocols, the OAuth 2.0 template is designed for scenarios that require authorization and token-based access primarily for APIs, and the OpenID Connect template is geared toward modern applications looking for user authentication with an identity provider. None of these templates fulfill the requirements for a custom ASP.NET application requiring federation as effectively as the WS-Fed template.