HP HPE7-A07 Exam With Confidence Using Practice Dumps

In Aruba AOS-CX, OSPF neighbors that reach EXSTART/EXCHANGE but fail to advance typically indicate a database description (DD) negotiation issue, most commonly caused by an MTU mismatch on the link. The OSPF header carries the interface MTU; if the values do not match, the peer rejects DD packets and the adjacency remains stuck at EXSTART (often shown as EXSTART/DR or EXSTART/BDR).

Aruba’s OSPF guidance states:

“If neighbors remain in EXSTART/EXCHANGE, verify that the Layer-3 MTU matches on both ends of the adjacency. An MTU mismatch causes DD packets to be rejected and prevents the adjacency from reaching FULL.”

Recommended corrective action is to align or remove custom L3 MTU settings on the participating interfaces (or use the mtu-ignore feature where appropriate).

In this scenario, removing the custom Layer-3 MTU configuration so both sides use the same default MTU allows DD packet negotiation to succeed and the adjacency to progress to FULL.

The issue indicated by the output is an invalid pre-shared key (PSK). The logs show multiple failures during the WPA2 key exchange process, which points to a mismatch between the PSK configured on the client device and the PSK expected by the AOS 10 mobility gateway.

The provided output is from the command:

(MC2) #show auth-tracebuf mac

This command traces the authentication exchange between the access point (or mobility controller) and the RADIUS server for a specific client. The trace provides insight into the 802.1X authentication sequence and RADIUS responses.

From the exhibit:

EAPOL (Extensible Authentication Protocol over LAN) Messages Observed:

eap-id-req

eap-id-resp

eap-req

eap-resp

eap-success

These messages clearly indicate that an 802.1X (EAP-based) authentication took place. MAC authentication (MAB) or WebAuth would not include multiple EAP identity and response messages.

RADIUS Messages:

rad-req, rad-resp, rad-accept from /RADIUS1

The presence of rad-accept indicates successful authentication.

Exact extract from ArubaOS (AOS-S/AOS 10 WLAN Authentication Guide):

“When the trace output shows EAP identity requests, EAP responses, and a RADIUS Access-Accept message, the authentication method in use is 802.1X (EAP-based user authentication). The presence of EAP-Success following the Access-Accept confirms successful 802.1X authentication.”

Follow-on WPA2 Key Exchange:

Lines show wpa2-key1, wpa2-key2, wpa2-key3, and wpa2-key4.

This sequence occurs after 802.1X authentication completes and is used to establish encryption keys for a WPA2 Enterprise session.

Exact extract from Aruba WLAN Troubleshooting Guide:

“After successful 802.1X authentication (EAP-Success), the controller exchanges four WPA2 keys with the station to derive the session keys used for data encryption. This confirms WPA2-Enterprise with 802.1X was used.”

No Indication of MAC or WebAuth:

MAC authentication would show mac-auth or macauth messages instead of eap-id-req/resp.

WebAuth involves HTTP-based redirection and is not visible in auth-tracebuf as EAP transactions.

Exact extract:

“MAC authentication shows ‘macauth start’ and ‘macauth accept’ entries, not EAPOL frames. WebAuth authentication uses a web redirect and does not appear as EAP frames in the trace buffer.”

Therefore, the trace confirms a WPA2-Enterprise 802.1X user authentication, where the user’s credentials were validated by the RADIUS server, followed by the WPA2 key handshake.

Why the Other Options Are Incorrect:

A. MAC authentication:Would show MAC-based request/response entries (macauth), not eap-id-req/resp.

C. WEBauth authentication:WebAuth occurs over HTTP/HTTPS and does not involve EAP messages; thus, no eap-id or eap-success would be seen.

D. 802.1X machine authentication:Machine authentication occurs before user logon and is typically identified in logs by a computer account (e.g., host/computername$). Here, the username and context indicate a user-level session.

References of HPE Aruba Networking Switching Documents or Study Guide:

ArubaOS 8/10 WLAN Authentication and Security Configuration Guide – “802.1X EAP Authentication and Trace Analysis.”

Aruba WLAN Troubleshooting Guide – “Using show auth-tracebuf to validate EAP authentication.”

Aruba Campus Wireless Design Fundamentals – “Understanding WPA2-Enterprise authentication flow (EAPOL, RADIUS, WPA2 4-Way Handshake).”

Aruba Access Security and AAA Implementation Guide – “Distinguishing between MAC, WebAuth, and 802.1X authentication in debug outputs.”