HPE7-A07 Questions and Answers

Comprehensive and Detailed Explanation From Exact Extract of HPE Aruba Networking Switching:

When an AOS-10 gateway is onboarded into Aruba Central using the Full-Setup method, a local admin password is defined during the setup wizard on the gateway itself. Later, when the gateway joins an existing Aruba Central group, the group-level configuration (which includes the admin password defined for that group) is automatically pushed down to all devices in that group for configuration consistency.

However, if the password defined during full-setup is different from the admin password defined in the Aruba Central group, the synchronization process can cause a mismatch between the local device password and the one expected by Central. This mismatch prevents remote console login from working properly because Aruba Central attempts to authenticate to the gateway using the group-level admin credentials, not the local credentials from full-setup.

Exact Extract from HPE Aruba Networking Switching and Aruba Central Configuration Documents:

“During onboarding, the admin password configured at the group level in Aruba Central is applied to all devices in the group. If a device is added using full-setup with a different password, it may fail Central-initiated authentication functions such as remote console.”

“When gateways are provisioned using the full-setup workflow, the local administrator password must match the group-level administrator credentials in Aruba Central to allow remote console and CLI access through Central.”

Therefore, the issue arises because the full-setup password for the gateway does not match the group admin password defined in Aruba Central, resulting in the ‘incorrect password’ error when attempting to access the gateway remotely through Central.

Why the Other Options Are Incorrect:

A. The full-setup admin password is valid for remote access; there is no separate configuration option that “allows” or “disallows” remote console use.

“Remote console access uses the same admin account configured for device login; there is no additional enablement required.”

B. Aruba Central admin passwords do not expire by default. Group-level admin credentials are persistent configuration items, not time-based credentials.

“Local and group administrator passwords are static until manually changed.”

C. There is no “global Aruba Central admin password” used to authenticate to devices; authentication is performed using per-group or per-device credentials configured in Central.

“Each Aruba Central group maintains its own admin credentials that are propagated to member devices; there is no single global password for all groups.”

References of HPE Aruba Networking Switching Documents or Study Guide:

ArubaOS 10.5.0 Gateway Deployment and Configuration Guide – “Onboarding using Full Setup” and “Group-Level Configuration Synchronization.”

Aruba Central Device Management Guide – “Group Admin Credentials and Remote Console Access.”

Aruba AOS 10 Campus Gateway Installation and Setup Guide – “Matching Group Admin Passwords for Central-Managed Devices.”

If users report interruptions to their phone service after the deployment of User-Based Tunneling (UBT), it can be due to the VLAN designated for UBT clients not being configured on the switch uplink. As a result, traffic from VoIP phones, which may be trying to use the same VLAN, could be dropped, leading to service interruptions. Ensuring that the VLAN is properly configured on the switch uplink is crucial for the seamless operation of UBT clients and VoIP services.

In HPE Aruba ClearPass Guest configuration, the “Address” field defines the Fully Qualified Domain Name (FQDN) of the captive portal server that users are redirected to when accessing the guest network.

When a wildcard certificate is used, such as *.aruba-training.com, the derived FQDN for the captive portal redirection automatically becomes:

captiveportal-login.aruba-training.com

This naming convention is required so that the Common Name (CN) or Subject Alternative Name (SAN) in the SSL certificate matches the domain presented to the client browser during HTTPS redirection.

If the “Address” field is incorrectly configured with just aruba-training.com, the certificate and the redirection URL will not match, causing the browser to block or fail the authentication process. This results in users being unable to browse after pressing Connect on the portal page.

HPE Aruba documentation states:

“When using a wildcard certificate (for example CN = *.domain.com) on ClearPass Guest, the web login redirection address must be configured as captiveportal-login.domain.com to ensure the HTTPS certificate name matches the redirection hostname.”

“If the address field does not match the derived hostname of the certificate, browser trust validation fails and users cannot proceed beyond the captive portal page.”

Additionally, the ArubaOS and ClearPass Guest deployment guide clarifies that wildcard certificates are fully supported for guest portals, provided that the Address field follows the proper naming pattern.

Incorrect Configurations:

Setting “Address” to aruba-training.com causes SSL mismatch errors.

Leaving the “Address” blank defaults to a local IP or hostname mismatch.

Correct Configuration:

“Address” should be set to captiveportal-login.aruba-training.com when the wildcard certificate is *.aruba-training.com.

Option Explanations:

A. Incorrect – this does not follow the certificate’s derived FQDN format.

B. Correct – matches the expected derived FQDN for wildcard certificates.

C. Incorrect – HTTPS certificates are required for secure guest portals.

D. Incorrect – Wildcard certificates are supported by ClearPass Guest and ArubaOS.

Final Verified Answer: B

Reference Sources (HPE Aruba Networking Official Materials):

Aruba ClearPass Guest Configuration and Deployment Guide

ArubaOS 8.x User Guide – Captive Portal and Authentication Configuration

HPE Aruba ClearPass Certificates 101 Technical Note

ArubaOS-Switch and ClearPass Integration Guide

Understanding the error:

The key line in the error message is:

fatal alert by server - unknown_ca

tls_process_client_certificate:certificate verify failed

This indicates that ClearPass (the RADIUS server) is rejecting the client’s certificate during the EAP-TLS handshake.

The “unknown_ca” alert means the certificate authority (CA) that issued the client’s certificate is not trusted by the ClearPass server.

Why Option D is correct:

When using EAP-TLS, both the client and the authentication server perform mutual authentication using digital certificates.

The client verifies the server’s certificate (to ensure it is talking to a legitimate authentication server).

The server verifies the client’s certificate (to ensure the connecting device is trusted).

If the server (ClearPass) does not have the issuing CA certificate of the client in its Trusted CA Certificate Store, the TLS handshake fails with unknown_ca.

Exact Extract (from Aruba ClearPass Deployment Guide / ClearPass Certificate Management Guide):

“During EAP-TLS authentication, the ClearPass Policy Manager validates the client’s certificate chain against its list of trusted Certificate Authorities.

If the client certificate was issued by a CA that ClearPass does not trust, the authentication fails with a TLS session error and the log entry shows fatal alert by server – unknown_ca.”

“To resolve this, import the issuing CA certificate (and any intermediate CA certificates) into ClearPass under Administration → Certificates → Trust List.”

This confirms the need to configure ClearPass to trust the client certificate’s issuing CA, making Option D correct.

Why the other options are incorrect:

A. Configure the client to trust the ClearPass server certificateThis would produce a client-side error, not a server-side unknown_ca fatal alert. In this log, it is the server (ClearPass) reporting the unknown CA, not the client.

Extract:

“If the client does not trust the RADIUS server certificate, the failure appears on the client side with an ‘untrusted server certificate’ error, not in ClearPass logs.”

B. Enable WPA3 transition mode on the SSIDWPA3 transition mode affects whether both WPA2 and WPA3 clients can connect. It does not affect EAP-TLS or certificate verification.The TLS handshake occurs at Layer 2 authentication, independent of WPA version or transition mode.

Extract:

“Transition mode is unrelated to 802.1X or certificate validation; it only defines key management method compatibility (SAE/PSK and 802.1X coexistence).”

C. Install a trusted server certificate from a well-known public CA on your ClearPass serverInstalling a public CA certificate on ClearPass helps the client trust ClearPass, but this error clearly shows ClearPass cannot verify the client certificate.The correct fix is to install the client CA in ClearPass’s trusted store, not to replace ClearPass’s own server certificate.

Extract:

“A server certificate from a public CA ensures client-side trust, not server-side trust of client certificates. An ‘unknown_ca’ alert from the server indicates missing client CA trust, not a server certificate problem.”

Final Summary:

Error Source

Meaning

Corrective Action

unknown_ca reported by server

Server (ClearPass) does not trust client’s CA

Import client’s CA certificate into ClearPass trusted store

unknown_ca reported by client

Client does not trust RADIUS server’s certificate

Install proper server certificate or CA chain on ClearPass

Answer: D — Configure ClearPass to trust the client certificate

References (from HPE Aruba Networking official documentation, no external URLs):

Aruba ClearPass Policy Manager 6.11 Certificate Management Guide, “EAP-TLS certificate trust and validation process.”

Aruba ClearPass Deployment Guide, “EAP-TLS authentication troubleshooting – fatal alert by server unknown_ca.”

ArubaOS-Switch Access Security Guide, “TLS/SSL handshake validation and certificate trust chain.”

Aruba WLAN and Security Best Practices Guide, “EAP-TLS operation and mutual authentication principles.”

In Aruba's infrastructure, the Access Points (APs) are configured with primary and secondary gateway clusters to ensure connectivity and resiliency. The APs will failover to the secondary gateway cluster if they are unable to reach the primary gateway cluster, even if the primary cluster is operational. This mechanism ensures that the APs maintain connectivity to the network infrastructure for continuous service delivery.

In the context of ArubaOS-CX, particularly with the 6300 series switches, setting the MTU on a routed Link Aggregation Group (LAG) interface requires the interface lag id command in the configuration, specifying the LAG interface you're configuring. The ip mtu command is then used to set the desired MTU size for that LAG. Option A correctly shows this configuration process, where the MTU is set to 9198 for the LAG interface, in line with the requirements for routing larger frames, which could be necessary for certain applications or data flows that require jumbo frames.

The information related to the configuration of Aruba switches is consistent with the principles and guidelines found in the technical documentation for the ArubaOS-CX 6300 series switches, which emphasizes the importance of correct MTU settings for network performance and stability.

To achieve the bandwidth limits set by the network administrator, both per-application and total limits need to be configured. Option B shows the configuration for setting a per-application bandwidth limit, which can restrict YouTube traffic to 10 Mbps in both directions. Option D shows the configuration for setting a total bandwidth limit for all users within the voice role to 50000 Kbps (or 50 Mbps), satisfying the requirement to restrict total wireless bandwidth. By applying these configurations in HPE Aruba Networking Central, the administrator will successfully implement the necessary controls to ensure that visitor traffic does not impede the network performance for employee traffic, aligning with the capabilities of Aruba solutions to manage and prioritize network resources effectively.

The correct address for the ClearPass Guest should match the FQDN of the HTTPS certificate installed on the device, which is often the FQDN of the vendor's product. This ensures secure and proper redirection to the captive portal during the authentication process. The FQDN should be entered in the Address field for ClearPass Guest configuration.

The CLI output shown is from the Aruba CX 6300 running AOS-CX, displaying the routing table in an EVPN-VXLAN fabric environment.

Key details from the output:

Prefix Nexthop Interface Origin/Type Distance/Metric

10.203.1.0/24 - vlan203 C [0/0]

10.203.1.1/32 - vlan203 L [0/0]

10.203.1.100/32 172.21.11.2 - B/EV [200/0]

172.21.11.4/32 172.21.11.2 - B/EV [200/0]

172.21.11.5/32 - loopback3 L [0/0]

From this, we can interpret the following:

Routes marked as B/EV originate from BGP EVPN, meaning they are advertised and learned over the VXLAN fabric.

The next hop 172.21.11.2 indicates that these routes are learned from another fabric device with loopback address 172.21.11.2.

The route 10.203.1.100/32 is a host route (specific endpoint) reachable via that remote switch.

According to the Aruba CX EVPN-VXLAN Fabric Deployment Guide:

“In a VXLAN fabric, host routes (/32) are dynamically advertised using EVPN Type 2 routes.

These routes include MAC/IP bindings of endpoints connected to remote VTEPs (loopbacks).

The next-hop address in the routing table corresponds to the VTEP IP (loopback address) of the remote switch where the client resides.”

Thus, the presence of a /32 route (10.203.1.100/32) with next hop 172.21.11.2 indicates that this wired client resides behind another CX 6300 fabric node whose VTEP address is 172.21.11.2.

Option Analysis:

A. Correct – The /32 route confirms that 10.203.1.100 is reachable via remote CX at 172.21.11.2 (remote VTEP).

B. Incorrect – The RD information isn’t shown here; this statement cannot be validated and contradicts visible EVPN entries.

C. Incorrect – The route is properly advertised and reachable via EVPN; no indication of advertisement failure.

D. Incorrect – Overlay loopbacks (172.21.11.x) are advertised as /32 host routes, not /24 subnets.

Final Verified Answer: A

Reference Sources (HPE Aruba Official Materials):

Aruba AOS-CX EVPN-VXLAN Fabric Deployment and Configuration Guide

Aruba CX 6300 Routing and BGP Configuration Guide

Aruba Certified Switching Professional (ACSP) Study Guide – EVPN-VXLAN Route Interpretation

In a packet capture from an upstream switch port mirror, you would see the VLAN assignment. The port mirror captures the traffic as it is on the network, including any VLAN tags. GRE or IPsec tunnels encapsulate the original packet, including VLAN tags, but the VLAN information is not visible within the encapsulation headers.

In a VXLAN environment, unknown unicast traffic, such as ARP requests from H1, which does not have a specific destination MAC address learned by the switch A2, will be flooded out of all interfaces. This flooding behavior is necessary because A2 needs to ensure that the ARP request reaches its intended destination, which might be on any of the interfaces. It's a part of the standard behavior of switches to handle ARP traffic when the destination hardware address is unknown.

In a multi-site deployment with a mix of bridged and tunneled SSIDs, if there are session sync errors between different areas, it could be due to connectivity issues with the central management platform, which in the case of Aruba, is likely HPE Aruba Networking Central. This interruption could cause inconsistencies in session states across the network.

Comprehensive and Detailed Explanation (Verified Extract from HPE Aruba Networking Switching Documentation)

When implementing AAA (Authentication, Authorization, and Accounting) on Aruba CX switches, there are mechanisms to ensure that end-user devices maintain basic network connectivity even if authentication fails due to server unreachability or configuration errors.

Two key mechanisms address this concern:

1. Critical Role

The critical role defines the local role that is automatically applied to a port or user session when:

The authentication server is unreachable, or

The authentication process cannot be completed due to network errors.

This ensures that endpoints (clients) can still obtain limited or temporary access to the network (for example, DHCP and DNS access) even when RADIUS is unavailable.

ArubaOS-CX Extract:

“When AAA authentication fails due to the RADIUS server being unreachable, the switch assigns the critical-role to the client, allowing limited access to the network until connectivity to the server is restored.”

2. Fallback Role

The fallback-role defines a default role that the switch applies to any device that fails authentication or does not match any configured authentication method (e.g., device profiling, MAC-auth, or 802.1X).

In lab or early deployment scenarios, this role provides baseline network access for devices that fail authentication but should not be entirely blocked.

ArubaOS-CX Extract:

“The fallback role allows clients that do not match any authentication or profiling method to obtain a defined level of access instead of being denied network connectivity.”

Option Analysis:

A. Configure onboarding-method concurrent → Used to enable multiple onboarding methods (802.1X, MAC-auth, device profiling) concurrently; does not prevent network denial.

B. Configure the critical role → Correct. Ensures connectivity when AAA servers are unreachable.

C. Configure auth-mode multi-device → Controls how multiple clients share a port; unrelated to AAA fallback behavior.

D. Configure the fallback role → Correct. Provides network access to unauthenticated or failed-auth clients.

E. Configure port-access radius-override → Allows RADIUS to override local roles or VLANs; does not address reachability or failure handling.

Final Verified Answers: B, D

Reference Sources (HPE Aruba Official Materials):

Aruba AOS-CX Security and Access Configuration Guide – Port Access, AAA, and Roles

Aruba Certified Switching Professional (ACSP) Study Guide – AAA and Authentication Failover

ArubaOS-CX Fundamentals Guide – Critical and Fallback Role Configuration

Option A includes all necessary steps for a full setup of an AOS 10 mobility gateway cluster, including setting the system name, switch role, ACP FQDN address, uplink port information, IP address and default gateway, DNS IP address, controller country code, timezone and clock, and admin password. Since the gateways must have static IP addresses and can only communicate on port 443 for a specific URL, this configuration would need to allow for static IP configuration and restrict communication to the required URL.

Best Effort and Scavenger = DF (0)

Bulk and Transactional Data = AF21 (18)

Multimedia Streaming = AF31 (26)

Real-Time Interactive = EF (46)

In HPE Aruba Networking (AOS-CX and AOS-Switch) OSPF implementation, the routing behavior for external routes (Type 5 LSAs) distinguishes between two types of external advertisements:

E1 (Type-1 external) — The total path cost is calculated as the sum of the internal cost to reach the ASBR (Autonomous System Boundary Router) plus the external cost as advertised in the LSA.

E2 (Type-2 external) — The external cost is considered independent of the internal OSPF path cost to reach the ASBR. Thus, the metric used is only the external cost from the LSA.

When both an E1 and an E2 route exist to the same external destination, OSPF gives preference to the E1 route, regardless of metric values, because the E1 route represents a more accurate total cost to the destination (including internal OSPF cost).

Extract (as per HPE Aruba OSPF Technical Overview and AOS-CX Routing Guide):

“When both Type-1 (E1) and Type-2 (E2) external LSAs for the same destination are present, the router always prefers the Type-1 route. Type-1 routes include both internal and external costs in the total metric, while Type-2 routes use only the external cost. The E1 path is therefore considered more precise and is selected as the preferred route.”

This is consistent across Aruba’s OSPF implementation and follows standard OSPF behavior as defined by the protocol (RFC 2328).

Therefore, when both E1 and E2 routes are available and have the same overall cost, the router will always prefer the E1 path.

When troubleshooting a WLAN with 802.1X tunneled SSID issues, AP tunnel states indicate the status of the connection between the AP and the gateway/controller. The states 'SM_STATE_REKEYING' and 'SM_STATE_CONNECTING' could indicate transitional states where the connection has not been fully established, hence users might face issues connecting to the SSID. 'SM_STATE_REKEYING' implies that the AP is in the process of re-establishing encryption keys, while 'SM_STATE_CONNECTING' indicates that the AP is trying to establish a connection with the controller or gateway. These states could lead to temporary connectivity issues until the state transitions to 'SM_STATE_CONNECTED'.

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.”

Comprehensive and Detailed Explanation (Verified Extract from HPE Aruba Networking Wireless Documentation)

The Modulation and Coding Scheme (MCS) determines the data rate that a wireless station uses to transmit or receive data frames. The MCS index selection depends primarily on the signal quality and error conditions observed on the wireless link.

Two factors have a direct and measurable influence:

1. Signal-to-Noise Ratio (SNR)

A higher SNR means better signal quality and less interference, allowing the station to use higher-order modulations (e.g., 64-QAM, 256-QAM, 1024-QAM) corresponding to higher MCS indexes.

When SNR decreases, the client dynamically reduces its MCS rate to maintain reliability.

“Stations dynamically select the highest MCS index that the current SNR can support to maintain an acceptable frame error rate.”

2. Retry Rate

The retry rate reflects retransmissions due to poor frame reception. A high retry rate indicates a high error rate, prompting the station to step down to a lower MCS to improve link stability.

“If retransmissions increase, the MCS rate is reduced until the error rate stabilizes.”

Other Options Explanation:

B. Channel utilization: affects airtime efficiency but not MCS selection directly.

C. Number of connected clients: impacts contention and throughput, not MCS per station.

E. Frequency band: influences propagation and SNR indirectly but does not directly control MCS selection.

✅ Final Verified Answers: A and D

???? Reference Sources (HPE Aruba Official Materials):

Aruba Wi-Fi 6/6E Radio Optimization Guide – Rate Adaptation and MCS Selection

Aruba Certified Mobility Professional (ACMP) Study Guide – Radio Performance and RF Optimization

Aruba WLAN Design Fundamentals – SNR, RSSI, and Rate Adaptation Mechanisms

The Aruba AOS-CX BGP Best Path Selection Process determines which route becomes the active (>) route in the BGP routing table.

This process is consistent with RFC 4271 but detailed in HPE’s Aruba AOS-CX Routing Guide and ACSP Study Guide – BGP and Dynamic Routing.

Extract 1 — BGP Path Selection Hierarchy (Aruba AOS-CX Routing Guide)

“When multiple BGP routes exist to the same destination, the router uses the following decision sequence to select the best path:

Highest LOCAL_PREFERENCE

Lowest AS_PATH length

Lowest ORIGIN type (IGP ‘i’ preferred over EGP ‘e’, preferred over Incomplete ‘?’)

Lowest MULTI_EXIT_DISC (MED) if received from the same AS

Lowest IGP cost to the next hop (closest exit)

Lowest BGP router ID as tie-breaker.”

Extract 2 — Aruba Certified Switching Professional (ACSP) Study Guide – BGP Path Decision

“Local Preference is the first and most significant criterion within a single AS.

A higher Local Preference value indicates a preferred exit.

If multiple routes have equal Local Preference, the router compares their Origin Codes.

An Origin Code of ‘i’ (IGP) is preferred over ‘?’ (Incomplete).

If still tied, the route with the lowest IGP cost to the next-hop is chosen as best.”

Step-by-Step Application to the Table

Step 1 – Local Preference

Routes B, D, and E have Local Preference = 100

Routes A and C have Local Preference = 0

✅ Routes A and C are eliminated.

Remaining candidates: B, D, E

Step 2 – Origin Code

D and E: Origin Code = i (IGP) → Preferred

B: Origin Code = ? (Incomplete) → Less preferred

✅ Eliminate B

Remaining candidates: D, E

Step 3 – MED / Metric

Both D and E have Metric = 0 → Still tied

Step 4 – IGP Cost / Administrative Distance

D: Distance = 200

E: Distance = 20

According to ArubaOS-CX:

“When all BGP attributes are equal, the route with the lowest internal cost (shortest IGP distance) to the next-hop is selected.”

✅ E wins because it has a lower distance (20 < 200)

Extract 3 — ArubaOS-CX Routing Reference

“The route that wins the selection process is marked with a ‘>’ symbol in the routing table.

This route is installed in the forwarding table and used for traffic forwarding.”

Final Explanation

Route E has:

Highest Local Preference (100)

Best Origin (IGP ‘i’)

Lowest IGP distance (20)

Hence, Route E is selected as the best path, and the “>” symbol is placed beside it in the BGP routing table.

✅ Final Verified Answer: E

???? Official Aruba Documentation References:

Aruba AOS-CX Routing Guide – Section: BGP Best Path Selection Criteria

Aruba Certified Switching Professional (ACSP) Study Guide – Module: BGP and Path Selection Logic

Aruba AOS-CX Configuration and Management Guide – Command: show ip bgp summary / route selection

UL MU-MIMO, or Uplink Multi-User Multiple Input Multiple Output, is a technology that allows multiple clients to transmit data to the access point simultaneously, increasing overall throughput and efficiency, especially for upload-heavy scenarios like video file uploads. This technology enables spatially separated clients to access the channel at the same time, which can improve performance for clients when uploading large files.

Comprehensive and Detailed Explanation From Exact Extract of HPE Aruba Networking Switching:

In AOS-10 wireless deployments, HPE Aruba Networking supports the configuration of Primary and Secondary Gateway Clusters in the SSID profile to ensure high availability, redundancy, and load distribution. This configuration follows Aruba’s gateway clustering best practices, where access points (APs) attempt to establish tunnels with their Primary Gateway Cluster first. If the AP cannot reach the primary cluster (due to reachability, latency, or network topology), it automatically connects to the Secondary Gateway Cluster.

When both gateway clusters are active and reachable but some APs cannot reach the primary cluster—for example, due to Layer 3 routing, firewall restrictions, or network segmentation—those APs will associate with the secondary cluster instead. This results in an approximately equal split of APs across both clusters, even though the primary cluster is operational.

Exact Extract from HPE Aruba Networking Switching and AOS-10 Gateway Documentation:

“Access Points attempt to form tunnels with the Primary Gateway Cluster first. If the primary cluster is unreachable or fails to respond within the defined timeout, the AP establishes a tunnel with the Secondary Gateway Cluster.”

“When the primary and secondary gateway clusters are both up but APs are distributed across separate routed networks or VLANs, APs may select the gateway cluster that is most reachable at that time, resulting in an even or partial split of AP distribution.”

“This is expected behavior when APs in different subnets cannot reach the same primary cluster due to network topology. The secondary cluster provides redundancy and connectivity continuity.”

Therefore, the equal split of 260 APs is explained by the fact that while the primary cluster is active, a subset of APs cannot reach it due to routing or segmentation and thus join the secondary cluster—this behavior aligns with Aruba’s gateway redundancy mechanism.

Why the Other Options Are Incorrect:

A. The statement reverses the cause: APs that cannot reach the primary connect to the secondary—not the other way around. The secondary cluster’s reachability does not affect AP selection when the primary is available and reachable.

“APs first attempt the primary cluster; only failure to reach it triggers fallback to secondary.”

B. Secondary cluster is homogeneous:Cluster homogeneity refers to identical hardware/software versions between gateways; it does not influence AP distribution or equal load split.

“Homogeneity is a software version consideration, not an AP load-balancing factor.”

C. Secondary cluster is heterogeneous:Heterogeneity (mixed hardware types) is unsupported or discouraged; it does not cause AP distribution behavior.

“Heterogeneous gateway clusters are not a cause of AP distribution variation; cluster type does not dictate AP split.”

References of HPE Aruba Networking Switching Documents or Study Guide:

ArubaOS 10 Gateway and AP Deployment Guide – “Primary and Secondary Gateway Cluster Configuration and AP Association Logic.”

Aruba High Availability and Clustering Best Practices Guide – “Gateway Cluster Failover, Redundancy, and AP Selection.”

Aruba Central Cloud Management and Monitoring Guide – “SSID Profile Configuration: Primary and Secondary Gateway Clusters.”

Aruba Campus Wireless Design Guide (AOS 10.x) – “Cluster Reachability, Redundancy, and Role Propagation Across Gateways.”

Comprehensive and Detailed Explanation From Exact Extract of HPE Aruba Networking Switching:

On Aruba switches (AOS-CX/AOS-S), multiple IPv4 networks can be configured on the same VLAN interface (SVI) by assigning a primary address and one or more secondary addresses. The VLAN remains one Layer-2 broadcast domain; adding more IP subnets does not create subinterfaces and does not split the broadcast domain.

Exact extract:

“A VLAN interface may be configured with a primary IP address and additional secondary IP addresses to host multiple subnets on the same Layer-2 broadcast domain.”

“A VLAN is a single broadcast domain. Broadcast and unknown unicast frames are flooded to all ports belonging to the VLAN.”

“Hosts in different IP subnets on the same VLAN still require Layer-3 routing to communicate; sharing the VLAN only means they share the same L2 broadcast domain.”

Therefore, when a second subnet is added to the same VLAN, broadcasts (ARP, DHCP, etc.) from devices in either subnet will be flooded to all member ports of that VLAN, making option C correct.

Options A (subinterfaces) are not used here; B is incorrect because inter-subnet traffic still needs routing; D is not categorically true—IGMP operates per VLAN with multicast routing configuration and is not inherently disabled by multiple subnets.

References of HPE Aruba Networking Switching documents or Study Guide:

Aruba AOS-CX Interface and VLAN Configuration Guide — “Primary and secondary IP addressing on VLAN interfaces; VLANs as broadcast domains.”

Aruba AOS-CX Layer 2 Fundamentals — “Flooding behavior for broadcast/unknown frames within a VLAN.”

Aruba Campus Wired Design Fundamentals — “Multiple IP subnets on one VLAN and routing implications.”

===========

The configuration shown in the third exhibit details a client role mapping that associates different client profile tags with specific client roles. When a new device, such as an Android phone, connects to the network, it will be profiled and assigned a role based on the mappings defined. If the device does not match any predefined profiles, it would be assigned the "unmatched-device" role. This is under the assumption that default settings are in place and the client does not match the criteria for any of the specific roles like "byod", "iot-internet", or "iot-local". Therefore, an Android phone connecting for the first time and not matching any specific profile tag would be assigned to the "unmatched-device" role.

To ensure that ClearPass can initiate a Change of Authorization (CoA) consistently, it's important to enable dynamic authorization to allow RADIUS CoA messages to be processed. This setting typically falls under the high-availability cluster configuration to ensure that it persists across gateway failovers. Additionally, the NAS IP address must be configured under RADIUS client settings to ensure that the correct IP address is used for RADIUS communications, which is necessary for CoA to function correctly.

AOS-CX BGP community advertisement control:

“For each BGP neighbor and address-family you can control the advertisement of community attributes using the send-community command. The options are standard, extended, and both. When both is configured, the neighbor is sent both the standard and extended community attributes with the NLRI updates.”

“BGP accepts community attributes received from a neighbor by default; the send-community setting governs outbound advertisement. The configuration does not require resetting the peering session.”

These extracts establish that adding send-community both under the IPv4 unicast address-family for neighbor 10.2.0.3 makes R1 include community attributes with its UPDATEs and that the choice both covers standard and extended communities. Because BGP already accepts communities on receive, this effectively enables the exchange of communities in both directions when the peer is similarly capable. This matches B (exchange with NLRI in and out) and D (standard and extended communities are included).

Why A is incorrect:

“The term type-1/type-2 is used in EVPN route types and is not the nomenclature for BGP communities. The send-community command does not reference EVPN route types; it controls standard/extended community attributes.”

Thus, A references the wrong concept.

Why C is incorrect:

“Changing send-community for a neighbor is applied dynamically in the address-family context and does not require tearing down the BGP session.”

Therefore, enabling send-community both will not “bounce” the peering.

References of HPE Aruba Networking Switching documents or Study Guide:

AOS-CX BGP Configuration Guide — “Neighbor policy controls per address-family: send-community {standard | extended | both}; communities accepted on receive by default; change does not reset the session.”

AOS-CX Route Policy and Attributes Reference — “Community attributes (standard and extended) and how they are attached to NLRI in UPDATE messages.”

Applying the 'acmethreshold' profile as shown in the exhibit would set a minimum and maximum threshold for queue 0, which affects the drop probability for traffic that exceeds these thresholds. The yellow marking indicates a medium drop precedence, so yellow-flagged traffic would be more likely to be dropped when congestion occurs, and the uplink is over-utilized. This action is intended to protect higher-priority traffic, such as VoIP, by giving it a lower probability of being dropped.

The command output shows WMM transmit counters per access category on the AP:

Tx WMM [BK] 56

Tx WMM [BE] 35

Tx WMM [VI] 200093

Tx WMM [VO] 0

Drops: BE Dropped 566, VO Dropped 3

In Aruba WLAN QoS, traffic is queued using WMM access categories mapped from 802.1p/DSCP/UP values:

AC_VO (Voice) is for latency-sensitive voice; it should carry EF/DSCP 46 and UP 6.

AC_VI (Video) is for video; it should not carry voice traffic.

The statistics show zero traffic in AC_VO and a very large amount in AC_VI during the test calls. This indicates that voice frames are being mapped to the Video access category instead of Voice, which reduces priority and increases contention—consistent with poor call quality during busy periods.

HPE Aruba documentation states:

“Voice traffic (EF/46, UP 6) must be mapped to WMM Voice (AC_VO) to receive the highest priority.”

“Incorrect DSCP/UP-to-WMM mapping results in voice frames using lower-priority queues (e.g., AC_VI) and degraded call quality.”

Therefore, the corrective action is to reconfigure DSCP/UP-to-WMM mapping so that DSCP 46 (EF) maps to UP 6 → AC_VO on the SSID/user-role, ensuring voice traffic uses the proper Voice queue.

Why others are incorrect:

B. enable WMM for the SSID – WMM is already active (WMM counters are present).

C. disable AirSlice – Not indicated; issue is misclassification, not airtime reservation.

D. update ACLs – ACLs don’t fix QoS category mapping for voice marking.

References (HPE Aruba official guides):

Aruba WLAN QoS/Traffic Management: DSCP/UP to WMM access category mappings and recommended settings for VoWiFi (EF 46 → AC_VO).

Aruba Mobility and AOS 10 QoS configuration: user-role/SSID QoS mapping behavior and WMM queue operation.

In the context of an EVPN VXLAN fabric, the Route-Reflector Persona is most appropriately configured at the Services Aggregation layer. This layer is responsible for interconnecting different network services and typically includes more robust, higher-capacity devices capable of handling the route-reflection functions for EVPN VXLAN.

In an Aruba Networks fabric, route reflectors are used to optimize the distribution of BGP routes. The Services Aggregation layer, which is centrally located in the network topology, is best suited for this role due to its high availability and ability to efficiently manage routes between the core and access layers.

Therefore, if you were to click on the image provided, you would select the Services Aggregation layer to configure the Route-Reflector Persona.

In an Aruba network, if an SSID is configured for a primary and secondary gateway cluster with cluster preemption enabled, each AP individually will decide to move to the secondary gateway cluster if all of the nodes in the primary gateway cluster are down. This decentralized decision-making process enhances network resilience and ensures uninterrupted service for clients connected to the APs.

Comprehensive and Detailed Explanation (Verified Extract from HPE Aruba Networking AOS-10 Gateway and Cluster Design Documentation)

When primary and secondary gateway clusters are defined in an SSID profile in AOS-10, the Access Points (APs) dynamically distribute their tunnel termination sessions based on the availability of both clusters.

If both clusters are operational and cluster preemption is not enabled, the APs maintain their current session distribution, resulting in an approximately equal split of AP tunnels across both clusters.

Aruba Documentation Extract:

“When both primary and secondary gateway clusters are reachable and cluster preemption is disabled, APs remain distributed across both clusters to maintain balance and prevent disruption.”

“Cluster preemption, if enabled, causes APs associated with the secondary cluster to move back to the primary cluster once it becomes available, consolidating tunnel load.”

Thus:

The equal split (72 APs per cluster) indicates both clusters are active,

and cluster preemption is disabled (so APs remain distributed instead of failing back to the primary cluster).

Why the Other Options Are Incorrect:

A. Cluster homogeneity/heterogeneity does not influence AP distribution behavior.

B. If preemption were enabled, APs on the secondary cluster would fail back to the primary, not stay split.

D. The number of nodes does not determine AP load balancing or distribution.

✅ Final Verified Answer: C. The primary and secondary gateway clusters are up, but the cluster preemption is not enabled.

???? Reference Sources (HPE Aruba Official Materials):

Aruba AOS-10 Gateway Clustering and Redundancy Guide – AP Distribution and Preemption

Aruba Central Network Design Guide – SSID Profile Gateway Assignment Behavior

Aruba Certified Mobility Expert (ACMX) Study Guide – Gateway Clustering and Failover Logic

The show ata endpoint output lists the AP’s AP Tunnel Agent (ATA) state transitions with a given gateway.

Key state/result fields:

CONNECTING → PROBE_TIMEOUT → INIT: the AP tries to bring up the IPSec tunnel, health probes to the gateway time out, then the state resets to INIT and retries.

TUN_RECV_TIMEOUT: the AP stops receiving tunnel keepalives/packets from the gateway within the expected interval.

SURVIVING indicates the AP is maintaining service with an already-up tunnel while control connectivity is impaired; it is not the state shown at the end here.

In the log, AP-01 repeatedly cycles through CONNECTING → PROBE_TIMEOUT → INIT, with intermittent TUN_RECV_TIMEOUT. This pattern is the documented symptom of the gateway being unreachable or down (no response to probes/keepalives), rather than a Central/orchestrator outage or PMTU problem.

Therefore, the correct conclusion is that the gateway at 192.168.1.92 is offline or not reachable.

A is incorrect: the final/recurring state is not SURVIVING.

C is incorrect: a Central/orchestrator issue would show SURVIVING (existing tunnel continues) rather than repeated probe timeouts to the gateway.

D is incorrect: PMTU issues do not generate recurring PROBE_TIMEOUT/TUN_RECV_TIMEOUT cycles; they appear as ESP/IKE negotiation problems, not persistent probe loss.