Pass the HP Aruba-ACNSA HPE6-A78 Questions and answers with CertsForce

Aruba ClearPass Device Insight offers a significant benefit by providing highly accurate endpoint classification. This feature is particularly useful in complex environments with a wide variety of device types, including IoT devices. Accurate device classification allows network administrators to better understand the nature and behavior of devices on their network, which is crucial for implementing appropriate security policies and ensuring network performance and security.

In an AOS-8 Mobility Controller (MC) environment, a WLAN is configured with WPA3-Enterprise security, using HPE Aruba Networking ClearPass Policy Manager (CPPM) for authentication. The WLAN’s default role is set to "guest," which would be applied if no specific role is assigned after authentication. The MC has several roles configured, including "general-access" (note the underscore in the question: "general_access").

The client successfully authenticates, and CPPM sends an Access-Accept message with an Aruba-User-Role Vendor-Specific Attribute (VSA) set to "general_access." In AOS-8, the Aruba-User-Role VSA is used to assign a specific role to the client, overriding the default role configured on the WLAN. The role specified in the VSA must match a role that exists on the MC. Since "general-access" (or "general_access" as written in the question) is listed among the roles configured on the MC, the MC will apply this role to the client.

The underscore in "general_access" in the VSA versus the hyphen in "general-access" in the MC’s role list is likely a typographical inconsistency in the question. In practice, AOS-8 role names are case-insensitive and typically use hyphens, not underscores, but for the purpose of this question, we assume "general_access" matches "general-access" as the intended role.

Option A, "guest," is incorrect because the guest role is the default 802.1X role for the WLAN, but it is overridden by the Aruba-User-Role VSA specifying "general_access."

Option B, "logon," is incorrect because the logon role is typically applied during the authentication process (e.g., to allow access to DNS or RADIUS servers), not after successful authentication when a specific role is assigned.

Option C, "general-access," is correct because the MC applies the role specified in the Aruba-User-Role VSA ("general_access"), which matches the "general-access" role configured on the MC.

Option D, "authenticated," is incorrect because the "authenticated" role is not specified in the VSA, and there is no indication that it is the default role for successful authentication in this scenario.

The HPE Aruba Networking AOS-8 8.11 User Guide states:

"When a client authenticates successfully via 802.1X, the Mobility Controller checks for an Aruba-User-Role VSA in the RADIUS Access-Accept message. If the VSA is present and the specified role exists on the controller, the controller assigns that role to the client, overriding the default 802.1X role configured for the WLAN. For example, if the VSA specifies ‘general-access’ and this role is configured on the controller, the client will be assigned the ‘general-access’ role." (Page 305, Role Assignment Section)

Additionally, the HPE Aruba Networking ClearPass Policy Manager 6.11 User Guide notes:

"The Aruba-User-Role VSA allows ClearPass to assign a specific role to a client on an Aruba Mobility Controller. The role name sent in the VSA must match a role configured on the controller, and the controller will apply this role to the client session, ignoring the default role for the WLAN." (Page 289, RADIUS Enforcement Section)

In an HPE Aruba Networking AOS-8 architecture with a Mobility Master (MM), Mobility Controllers (MCs), and campus APs (CAPs), the WLAN is configured to use Tunnel forwarding mode and WPA3-Enterprise security. In Tunnel mode, all user traffic from the APs is encapsulated in a GRE tunnel and sent to the MC, which then forwards the traffic to the appropriate VLAN. The WLAN is assigned to VLAN 301, and the core routing switches act as the default router for wireless user traffic.

Tunnel Forwarding Mode: In this mode, the AP does not directly place user traffic onto the wired network. Instead, the AP tunnels all user traffic to the MC over a GRE tunnel. The MC then decapsulates the traffic and places it onto the wired network in the specified VLAN (VLAN 301 in this case). This means the VLAN tagging for user traffic occurs at the MC, not at the AP.

VLAN 301 Assignment: Since the WLAN is assigned to VLAN 301, the MC will tag user traffic with VLAN 301 when forwarding it to the wired network. The core routing switches, acting as the default router, need to receive this traffic on VLAN 301 to route it appropriately.

Therefore, VLAN 301 needs to be carried on the links between the MC ports and the core routing switches, as this is where the MC forwards the user traffic after decapsulating it from the GRE tunnel.

Option A, "Only links on the path between APs and the core routing switches," is incorrect because, in Tunnel mode, the APs do not directly forward user traffic to the wired network. The traffic is tunneled to the MC, so the links between the APs and the core switches do not need to carry VLAN 301 for user traffic (though they may carry other VLANs for AP management).

Option B, "Only links on the path between APs and the MC," is incorrect for the same reason. The GRE tunnel between the AP and MC carries encapsulated user traffic, and VLAN 301 tagging occurs at the MC, not on the AP-to-MC link.

Option C, "All links in the campus LAN to ensure seamless roaming," is incorrect because VLAN 301 only needs to be present where the MC forwards user traffic to the wired network (i.e., between the MC and the core switches). Extending VLAN 301 to all links is unnecessary and could introduce security or scalability issues.

Option D, "Only links between MC ports and the core routing switches," is correct because the MC places user traffic onto VLAN 301 and forwards it to the core switches, which act as the default router.

The HPE Aruba Networking AOS-8 8.11 User Guide states:

"In Tunnel forwarding mode, the AP encapsulates all user traffic in a GRE tunnel and sends it to the Mobility Controller (MC). The MC decapsulates the traffic and forwards it to the wired network on the VLAN assigned to the WLAN. For example, if the WLAN is assigned to VLAN 301, the MC tags the user traffic with VLAN 301 and sends it out of its wired interface to the upstream switch. Therefore, the VLAN must be configured on the links between the MC and the upstream switch or router that acts as the default gateway for the VLAN." (Page 275, Tunnel Forwarding Mode Section)

Additionally, the HPE Aruba Networking Wireless LAN Design Guide notes:

"When using Tunnel mode, the VLAN assigned to the WLAN must be carried on the wired links between the Mobility Controller and the default router for the VLAN. The links between the APs and the MC do not need to carry the user VLAN, as all traffic is tunneled to the MC, which handles VLAN tagging." (Page 52, VLAN Configuration Section)

In an AOS-8 architecture with a Mobility Conductor (MC) and Mobility Controllers (MCs), the Traffic Analysis dashboard (available in the MC UI) allows administrators to monitor wireless clients’ application usage (e.g., identifying traffic from applications like Zoom, YouTube, or Skype). To enable this functionality, the MCs must be able to inspect and classify client traffic at the application level.

Firewall Visibility and DPI: The AOS-8 platform includes a stateful firewall that can perform deep packet inspection (DPI) to classify traffic based on application signatures. Enabling "firewall visibility" on the MCs activates DPI, allowing the firewall to inspect packet payloads and identify applications. This data is then used by the Traffic Analysis dashboard to display application usage statistics for wireless clients.

Option D, "Enabling firewall visibility and deep packet inspection (DPI) on the MCs," is correct. Firewall visibility must be enabled on the MCs to perform DPI and classify client traffic by application. This is typically done with the command firewall visibility in the MC configuration, which activates DPI and allows the Traffic Analysis dashboard to display application usage data.

Option A, "Configuring packet capturing on the MCs’ data plane," is incorrect. Packet capturing (e.g., using the packet-capture command) is used for manual troubleshooting or analysis, not for enabling the Traffic Analysis dashboard. Packet captures generate raw packet data, which is not processed for application usage statistics.

Option B, "Enabling logging on the users category on the MCs," is incorrect. Enabling logging for the "users" category (e.g., using the logging command) generates logs for user events (e.g., authentication, role assignment), but it does not provide application usage data for the Traffic Analysis dashboard.

Option C, "Discovering the mobility devices in HPE Aruba Networking Central," is incorrect. While discovering devices in Aruba Central can provide centralized monitoring, the Traffic Analysis dashboard in AOS-8 is a local feature on the MC and does not require Aruba Central. Additionally, application usage monitoring requires DPI on the MCs, not just device discovery.

The HPE Aruba Networking AOS-8 8.11 User Guide states:

"The Traffic Analysis dashboard on the Mobility Controller provides visibility into wireless clients’ application usage, such as identifying traffic from applications like Zoom or YouTube. To enable this feature, you must enable firewall visibility and deep packet inspection (DPI) on the MCs. Use the command firewall visibility to activate DPI, which allows the firewall to classify traffic by application. The classified data is then displayed in the Traffic Analysis dashboard under Monitoring > Traffic Analysis." (Page 360, Traffic Analysis Dashboard Section)

Additionally, the HPE Aruba Networking Security Guide notes:

"Firewall visibility on AOS-8 Mobility Controllers enables deep packet inspection (DPI) to classify client traffic by application. This is required for features like the Traffic Analysis dashboard, which displays application usage statistics for wireless clients, helping administrators monitor network activity." (Page 55, Firewall Visibility Section)

Opportunistic Wireless Encryption (OWE) provides encrypted communications on open Wi-Fi networks, which addresses the company's desire to have encryption without requiring a password for guests. It can work in transition mode, which allows for the use of OWE by clients that support it, while still permitting legacy clients to connect without encryption. Combining this with a captive portal enables the desired welcome web page for guests to log in.

In an AOS-8 architecture, the Mobility Controller (MC) includes a stateful firewall that enforces policies on client traffic. The firewall uses user roles to apply policies, allowing granular control over traffic based on the client’s identity and context.

User Roles: In AOS-8, each client is assigned a user role after authentication (e.g., via 802.1X, MAC authentication, or captive portal). The user role contains firewall policies (rules) that define what traffic is allowed or denied for clients in that role. For example, a "guest" role might allow only HTTP/HTTPS traffic, while an "employee" role might allow broader access.

Option A, "The firewall applies the rules in policies associated with the client's user role," is correct. The AOS firewall evaluates traffic based on the user role assigned to the client. Each role has a set of policies (rules) that are applied in order, and the first matching rule determines the action (permit or deny). For example, if a client is in the "employee" role, the firewall applies the rules defined in the "employee" role’s policy.

Option B, "The firewall applies every rule that includes the client's IP address as the source," is incorrect. The firewall does not apply rules based solely on the client’s IP address; it uses the user role. Rules within a role may include IP addresses, but the role determines which rules are evaluated.

Option C, "The firewall applies the rules in policies associated with the client's WLAN," is incorrect. While the WLAN configuration defines the initial role for clients (e.g., the default 802.1X role), the firewall applies rules based on the client’s current user role, which may change after authentication (e.g., via a RADIUS VSA like Aruba-User-Role).

Option D, "The firewall applies every rule that includes the client's IP address as the source or destination," is incorrect for the same reason as Option B. The firewall uses the user role to determine which rules to apply, not just the client’s IP address.

The HPE Aruba Networking AOS-8 8.11 User Guide states:

"The AOS firewall on the Mobility Controller applies rules based on the user role assigned to a client. Each user role contains a set of firewall policies that define the allowed or denied traffic for clients in that role. For example, a policy in the ‘employee’ role might include a rule like ipv4 user any http permit to allow HTTP traffic. The firewall evaluates the rules in the client’s role in order, and the first matching rule determines the action for the traffic." (Page 325, Firewall Policies Section)

Additionally, the HPE Aruba Networking Security Guide notes:

"User roles in AOS-8 provide a powerful mechanism for firewall policy enforcement. The firewall determines which rules to apply to a client’s traffic by looking at the policies associated with the client’s user role, which is assigned during authentication or via a RADIUS VSA like Aruba-User-Role." (Page 50, Role-Based Access Control Section)

Based on the exhibit, which shows the settings on the company's Mobility Controllers (MCs), with 'Control Plane Security' enabled and 'Enable auto cert provisioning' available, new Aruba 335-APs require approval on the MC to become managed. This is commonly done by adding the APs to an authorized AP whitelist, after which they can be automatically provisioned with certificates generated by the MC.

HPE Aruba Networking ClearPass Policy Manager (CPPM) uses device profiling to classify endpoints, and one of its passive profiling methods involves analyzing DHCP traffic. DHCP fingerprinting is a technique where ClearPass examines the DHCP packets sent by a client, particularly the DHCP Discover packet, to identify the device’s operating system or type based on specific attributes.

Option A, "It can determine information such as the endpoint OS from the order of options listed in Option 55 of a DHCP Discover packet," is correct. DHCP Option 55 (Parameter Request List) is a field in the DHCP Discover packet where the client specifies the list of DHCP options it requests from the server. The order and combination of these options are often unique to specific operating systems or device types (e.g., Windows, Linux, macOS, or IoT devices). ClearPass maintains a database of DHCP fingerprints and matches the Option 55 data against this database to classify the endpoint.

Option B, "It can respond to a client’s DHCP Discover with different DHCP Offers and then analyze the responses," is incorrect because ClearPass does not act as a DHCP server or send DHCP Offers. It passively snoops DHCP traffic rather than actively responding to DHCP requests.

Option C, "It can snoop DHCP traffic to register the clients’ IP addresses," is partially correct in that ClearPass does snoop DHCP traffic, but the purpose is not just to register IP addresses for HTTP probing. While ClearPass can use IP addresses for active probing (e.g., HTTP or SNMP), the question specifically asks about using DHCP to classify, which is done via fingerprinting, not IP registration.

Option D, "It can alter the DHCP Offer to insert itself as a proxy gateway," is incorrect because ClearPass does not modify DHCP packets or act as a proxy gateway. This is not a function of ClearPass in the context of DHCP-based profiling.

The HPE Aruba Networking ClearPass Policy Manager 6.11 User Guide states:

"ClearPass can profile devices using DHCP fingerprinting, a passive profiling method. When a device sends a DHCP Discover packet, ClearPass examines the packet’s attributes, including the order of options in DHCP Option 55 (Parameter Request List). The combination and order of these options are often unique to specific operating systems or device types. ClearPass matches these attributes against its DHCP fingerprint database to classify the device (e.g., identifying a device as a Windows 10 laptop or an Android phone)." (Page 247, DHCP Fingerprinting Section)

Additionally, the ClearPass Device Insight Data Sheet notes:

"DHCP fingerprinting allows ClearPass to passively collect device information without interfering with network traffic. By analyzing DHCP Option 55, ClearPass can accurately determine the device’s operating system and type, enabling precise policy enforcement." (Page 3)

The company wants to deploy an open WLAN for guests with the following requirements:

Guests connect without entering a password (open authentication).

Guests are redirected to a welcome web page and log in (captive portal).

Encryption is provided for devices that support it.

Open WLAN with Captive Portal: An open WLAN means no pre-shared key (PSK) or 802.1X authentication is required to connect. A captive portal can be used to redirect users to a web page where they must log in (e.g., with guest credentials). This meets the requirement for guests to connect without a password and then log in via a web page.

Encryption for Capable Devices: The company wants to provide encryption for devices that support it, even on an open WLAN. Opportunistic Wireless Encryption (OWE) is a WPA3 feature designed for open networks. OWE provides encryption without requiring a password by negotiating unique encryption keys for each client using a Diffie-Hellman key exchange. OWE in transition mode allows both OWE-capable devices (which use encryption) and non-OWE devices (which connect without encryption) to join the same SSID, ensuring compatibility.

Option A, "Opportunistic Wireless Encryption (OWE) and WPA3-Personal," is incorrect. WPA3-Personal requires a pre-shared key (password), which conflicts with the requirement for guests to connect without entering a password.

Option B, "Captive portal and WPA3-Personal," is incorrect for the same reason. WPA3-Personal requires a password, which does not meet the open WLAN requirement.

Option C, "WPA3-Personal and MAC-Auth," is incorrect. WPA3-Personal requires a password, and MAC authentication (MAC-Auth) does not provide the web-based login experience (captive portal) specified in the requirements.

Option D, "Captive portal and Opportunistic Wireless Encryption (OWE) in transition mode," is correct. An open WLAN with OWE in transition mode allows guests to connect without a password, provides encryption for OWE-capable devices (e.g., WPA3 devices), and supports non-OWE devices without encryption. The captive portal ensures that guests are redirected to a welcome web page to log in, meeting all requirements.

The HPE Aruba Networking AOS-8 8.11 User Guide states:

"Opportunistic Wireless Encryption (OWE) is a WPA3 feature that provides encryption for open WLANs without requiring a password. In OWE transition mode, the WLAN supports both OWE-capable devices (which use encryption) and non-OWE devices (which connect without encryption) on the same SSID. This is ideal for guest networks where encryption is desired for capable devices, but compatibility with all devices is required. A captive portal can be configured on an open WLAN to redirect users to a login page, such as captive-portal guest-login, ensuring a seamless guest experience." (Page 290, OWE and Captive Portal Section)

Additionally, the HPE Aruba Networking Wireless Security Guide notes:

"OWE in transition mode is recommended for open guest WLANs where encryption is desired for devices that support it. Combined with a captive portal, this setup allows guests to connect without a password, get redirected to a login page, and benefit from encryption if their device supports OWE." (Page 35, Guest Network Security Section)

In this scenario, a new HPE Aruba Networking Mobility Controller (MC) and campus APs (CAPs) are deployed, with a WLAN configured for 802.1X authentication using HPE Aruba Networking ClearPass Policy Manager (CPPM) as the RADIUS server. A client test fails, and no record of the authentication attempt appears in ClearPass Access Tracker. However, a ping from the MC to CPPM is successful, confirming basic network connectivity between the MC and CPPM.

The absence of a record in Access Tracker indicates that CPPM did not receive the RADIUS authentication request from the MC, or the request was rejected at a low level before being logged in Access Tracker. Access Tracker typically logs all RADIUS authentication attempts (successful or failed), so the lack of a record suggests a configuration or connectivity issue at the RADIUS level.

Option C, "Check CPPM Event Viewer," is correct. The CPPM Event Viewer logs system-level events, including RADIUS-related errors that might not appear in Access Tracker. For example, if the MC’s IP address is not configured as a Network Access Device (NAD) in CPPM, or if the shared secret between the MC and CPPM does not match, CPPM may reject the RADIUS request before it reaches Access Tracker. The Event Viewer will log such errors (e.g., "RADIUS authentication attempt from unknown NAD"), providing insight into why the request was not processed.

Option A, "Renew CPPM's RADIUS/EAP certificate," is incorrect because the issue is that CPPM did not receive or process the authentication request (no record in Access Tracker). If there were a certificate issue (e.g., an expired or untrusted certificate), the request would still reach CPPM, and Access Tracker would log a failure with a certificate-related error.

Option B, "Check connectivity between CPPM and a backend directory server," is incorrect because the issue occurs before CPPM processes the authentication request. If CPPM cannot contact a backend directory server (e.g., Active Directory), the authentication attempt would still be logged in Access Tracker with a failure reason related to the directory server.

Option D, "Reset the user credentials," is incorrect because the issue is not related to the user’s credentials. The authentication request never reached CPPM, so the credentials were not evaluated.

The HPE Aruba Networking ClearPass Policy Manager 6.11 User Guide states:

"If an authentication attempt does not appear in Access Tracker, it indicates that the RADIUS request was not received by ClearPass or was rejected at a low level before being logged. The Event Viewer (Monitoring > Event Viewer) should be checked for system-level errors, such as ‘RADIUS authentication attempt from unknown NAD’ or shared secret mismatches. For example, if the Network Access Device (NAD) IP address of the Mobility Controller is not configured in ClearPass, or if the shared secret does not match, the request will be dropped, and an error will be logged in the Event Viewer." (Page 301, Troubleshooting RADIUS Issues Section)

Additionally, the HPE Aruba Networking AOS-8 8.11 User Guide notes:

"When troubleshooting 802.1X authentication issues, verify that the Mobility Controller can communicate with the RADIUS server. If a ping is successful but no authentication records appear in the RADIUS server’s logs (e.g., ClearPass Access Tracker), check the RADIUS server’s system logs (e.g., ClearPass Event Viewer) for errors related to NAD configuration or shared secret mismatches." (Page 498, Troubleshooting 802.1X Authentication Section)