Which configuration is NOT appropriate for a custom ASP.net application requiring federation in Okta?

The chosen configuration, which is not appropriate for a custom ASP.NET application requiring federation in Okta, involves the use of the System for Cross-domain Identity Management (SCIM) template. SCIM is primarily designed for provisioning and managing user identities and does not facilitate user authentication. Unlike OIDC, SAML, or OAuth, SCIM is not an authentication protocol; rather, it is used for tasks such as creating, updating, or deleting user accounts across systems.

In the context of a custom ASP.NET application that requires federation, the other options are focused on enabling secure authentication mechanisms. OIDC and SAML are both well-suited for this purpose. OIDC allows applications to verify the identity of users based on the authentication performed by an authorization server, and it works well for web applications. SAML 2.0 is another widely-used standard for exchanging authentication and authorization data between parties, particularly between an identity provider and a service provider.

The OAuth 2.0 authorization server option leverages API Access Management, which is also relevant for enabling authentication and authorization, especially when access to an API is required. Therefore, the correct configuration involves selecting protocols designed for authentication, making the SCIM template an inappropriate choice for this scenario.