The question involves an EAP timeout in HPE Aruba Networking ClearPass Access Tracker during an 802.1X authentication attempt, with the task of identifying a possible cause.

Analysis of Options:

Option A:Incorrect. A client certificate trust issue would cause a different error, not an EAP timeout.

Option B:Incorrect. An expired client certificate would result in an authentication failure, not a timeout.

Option C:Incorrect. If the client sees an expired RADIUS server certificate, it would reject it, but this typically causes a trust error, not a timeout.

Option D:Correct. If the client does not trust the RADIUS server’s certificate (e.g., missing CA certificate or untrusted issuer), it may fail to proceed with the EAP handshake, leading to an EAP timeout.

Why Option D is Correct:In 802.1X authentication with EAP (e.g., EAP-TLS or EAP-PEAP), the client must trust the RADIUS server’s certificate to establish a secure TLS tunnel. If the client’s trust store lacks the Certificate Authority (CA) certificate or the server’s certificate is untrusted (e.g., self-signed without proper installation), the clientaborts the EAP handshake, resulting in an EAP timeout logged in ClearPass. This is a common issue in 802.1X deployments and can be resolved by ensuring the client has the correct CA certificate or by using a trusted server certificate, as per HPE Aruba Networking’s security guidelines.

Relevance to Certification Objectives:

Authentication/Authorization (9%):Troubleshooting 802.1X and ClearPass authentication issues.

Security (10%):Diagnosing wired 802.1X with EAP-TLS failures.

Troubleshooting (10%):Resolving authentication timeouts in campus networks.