A security engineer is configuring a wireless network with EAP-TLS. Which of the following activities is a requirement for this configuration?

TACACS+ is an AAA protocol primarily used for network device administration and is not the standard protocol typically paired with EAP for wireless user authentication; RADIUS is commonly used for this purpose.

Configuring federation between authentication servers allows for cross-domain identity management but is not a direct technical requirement for the EAP-TLS authentication process itself.

Enabling TOTP (Time-based One-Time Password) is a multi-factor authentication method that is separate from and not a prerequisite for configuring EAP-TLS, which uses certificates for authentication.

EAP-TLS (Extensible Authentication Protocol - Transport Layer Security) is a certificate-based authentication protocol that requires both the client and the server to present digital certificates for mutual authentication. Therefore, endpoint devices must have valid client certificates deployed to them to participate successfully in the EAP-TLS handshake.