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

Device fingerprinting on an AOS-CX switch allows the switch to collect information about connected clients to aid in profiling and policy enforcement, often in conjunction with a solution like ClearPass Policy Manager (CPPM). The commands provided create a device fingerprinting profile named "myprofile" and enable the collection of DHCP and LLDP information:

client device-fingerprint profile myprofile: Creates a fingerprinting profile.

dhcp: Enables the collection of DHCP information (e.g., DHCP options like Option 55 for fingerprinting).

lldp: Enables the collection of LLDP (Link Layer Discovery Protocol) information (e.g., system name, description).

However, creating the profile and enabling DHCP and LLDP collection is not enough for the switch to start collecting this information from clients. The profile must be applied to the interfaces (ports) where clients are connected.

Option C, "Apply the policy to edge ports," is correct. In AOS-CX, the device fingerprinting profile must be applied to the edge ports (ports where clients connect) to enable the switch to collect DHCP and LLDP information from those clients. This is done using the command client device-fingerprint profile under the interface configuration. For example, on port 1/1/1, you would enter:

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Switch(config)# interface 1/1/1

Switch(config-if)# client device-fingerprint profile myprofile

This ensures that the switch collects DHCP and LLDP data from clients connected to the specified ports.

Option A, "Configure the switch as a DHCP relay," is incorrect. While a DHCP relay (using the ip helper-address command) is needed if the DHCP server is on a different subnet, it is not a requirement for the switch to collect DHCP information for fingerprinting. The switch can snoop DHCP traffic on the local VLAN without being a relay, as long as the profile is applied to the ports.

Option B, "Add at least one LLDP option to the policy," is incorrect. The lldp command in the fingerprinting profile already enables the collection of LLDP information. There is no need to specify individual LLDP options (e.g., system name, description) in the profile; the switch collects all available LLDP data by default.

Option D, "Add at least one DHCP option to the policy," is incorrect. The dhcp command in the fingerprinting profile already enables the collection of DHCP information, including options like Option 55 (Parameter Request List), which is commonly used for fingerprinting. There is no need to specify individual DHCP options in the profile.

The HPE Aruba Networking AOS-CX 10.12 Security Guide states:

"To enable device fingerprinting on an AOS-CX switch, create a device fingerprinting profile using the client device-fingerprint profile command, and specify the protocols to collect, such as dhcp for DHCP information and lldp for LLDP information. To start collecting data from clients, apply the profile to edge ports where clients connect using the command client device-fingerprint profile under the interface configuration. For example, interface 1/1/1 followed by client device-fingerprint profile myprofile enables fingerprinting on port 1/1/1." (Page 160, Device Fingerprinting Configuration Section)

Additionally, the HPE Aruba Networking AOS-CX 10.12 System Management Guide notes:

"The device fingerprinting profile must be applied to the ports where clients are connected to collect DHCP and LLDP information. The dhcp and lldp commands in the profile enable the collection of all relevant data for those protocols, such as DHCP Option 55 for fingerprinting, without requiring additional options to be specified." (Page 95, Device Fingerprinting Setup Section)

Without the integration of Aruba ClearPass or other advanced network access control solutions, ArubaOS devices (controllers and Instant APs) are able to use DHCP fingerprinting to assign roles to clients. This method allows the devices to identify the type of client devices connecting to the network based on the DHCP requests they send. While this is a more basic form of endpoint classification compared to the capabilities provided by ClearPass, it still enables some level of access control based on device type. This functionality and its limitations are described in Aruba's product documentation for ArubaOS devices, highlighting the benefits of integrating a full-featured solution like ClearPass for more granular and powerful endpoint classification capabilities.

In the context of the ArubaOS Security Dashboard, if the goal is to find company clients that have connected to devices potentially operated by hackers, you would look for a client that is classified as 'Interfering' (indicating a security threat) while being connected to an 'AP Classification: Rogue'. A rogue AP is one that is not under the control of network administrators and is considered malicious or a security threat. Therefore, the client fitting this description is:

MAC address: d8:50:e6:f3:70:ab; Client Classification: Interfering; AP Classification: Rogue

Control Plane Policing (CoPP) on Aruba switches is used to mitigate Denial of Service (DoS) attacks on the switch. CoPP allows network administrators to restrict the impact of control plane traffic on the switch's CPU, thereby protecting network stability and integrity. By setting rate limits and specifying allowed traffic types, administrators can prevent malicious or malformed packets from overwhelming the switch's control plane, which could otherwise lead to a DoS condition and potentially disrupt network operations. This use case of CoPP is detailed in Aruba's network management documentation, where best practices and configurations to protect against DoS attacks are discussed.

In SNMPv3, security is paramount and each SNMP entity (client or agent) needs to have a user with a security name (username) and optionally, a security level which determines whether authentication and encryption are used. When configuring SNMPv3 users on network infrastructure devices, it is essential to match the username, authentication (auth) algorithm, authentication key (auth key), privacy (priv) algorithm, and privacy key (priv key) exactly as they are configured on the SNMP server to ensure successful communication.

This is because the SNMPv3 security model relies on a combination of a username and a pair of keys (authentication and privacy keys) to uniquely identify and secure communication between the agent and the manager. The keys are used to verify the integrity (auth key) and confidentiality (priv key) of the messages. Using the same algorithms ensures that the messages can be properly encrypted and decrypted on both ends.

The Aruba ClearPass Device Insight Analyzer plays a crucial role within the Device Insight architecture by residing in the cloud and applying machine learning and supervised crowdsourcing to the metadata sent by Collectors. This component of the architecture is responsible for analyzing vast amounts of data collected from the network to identify and classify devices accurately. By utilizing machine learning algorithms and crowdsourced input, the Device Insight Analyzer enhances the accuracy of device detection and classification, thereby improving the overall security and management of the network.

The ArubaOS Security Dashboard, part of the AOS-8 architecture (Mobility Controllers or Mobility Master), provides visibility into wireless clients and access points (APs) through its Wireless Intrusion Prevention (WIP) system. The goal is to identify clients that belong to the company (i.e., authorized clients) and have connected to devices that might belong to hackers (i.e., rogue APs).

Client Classification:

Authorized: A client that has successfully authenticated to an authorized AP and is recognized as part of the company’s network (e.g., an employee device).

Interfering: A client that is not authenticated to the company’s network and is considered external or potentially malicious.

AP Classification:

Authorized: An AP that is part of the company’s network and managed by the MC/MM.

Rogue: An AP that is not authorized and is suspected of being malicious (e.g., connected to the company’s wired network without permission).

Neighbor: An AP that is not part of the company’s network but is not connected to the wired network (e.g., a nearby AP from another organization).

The requirement is to find a client that is authorized (belongs to the company) and connected to a rogue AP (might belong to hackers).

Option A: MAC address: d8:50:e6:f3:70:ab; Client Classification: Interfering; AP Classification: RogueThis client is classified as "Interfering," meaning it does not belong to the company. Although it is connected to a rogue AP, it does not meet the requirement of being a company client.

Option B: MAC address: d8:50:e6:f3:6e:c5; Client Classification: Interfering; AP Classification: NeighborThis client is "Interfering" (not a company client) and connected to a "Neighbor" AP, which is not considered a hacker’s device (it’s just a nearby AP).

Option C: MAC address: d8:50:e6:f3:6e:60; Client Classification: Interfering; AP Classification: AuthorizedThis client is "Interfering" (not a company client) and connected to an "Authorized" AP, which is part of the company’s network, not a hacker’s device.

Option D: MAC address: d8:50:e6:f3:6d:a4; Client Classification: Authorized; AP Classification: RogueThis client is "Authorized," meaning it belongs to the company, and it is connected to a "Rogue" AP, which might belong to hackers. This matches the requirement perfectly.

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

"The Security Dashboard in ArubaOS provides a client list that includes the client classification and the AP classification for each client. A client classified as ‘Authorized’ has successfully authenticated to an authorized AP and is part of the company’s network. A ‘Rogue’ AP is an unauthorized AP that is suspected of being malicious, often because it is connected to the company’s wired network (e.g., detected via Eth-Wired-Mac-Table match). To identify potential security risks, look for authorized clients connected to rogue APs, as this may indicate that a company device has connected to a hacker’s AP." (Page 415, Security Dashboard Section)

Additionally, the HPE Aruba Networking Security Guide notes:

"An ‘Authorized’ client is one that has authenticated to an AP managed by the controller, typically an employee or corporate device. A ‘Rogue’ AP is classified as such if it is not authorized and poses a potential threat, such as being connected to the corporate LAN. Identifying authorized clients connected to rogue APs is critical for detecting potential man-in-the-middle attacks." (Page 78, WIP Classifications Section)

MAC authentication, also known as MAC-Auth, is a method used to authenticate devices based on their Media Access Control (MAC) address. It is often employed in both wired and wireless networks to grant network access based solely on the MAC address of a device. While MAC-Auth is straightforward and doesn’t require complex configuration, it has significant security limitations primarily because MAC addresses can be easily spoofed. Attackers can change the MAC address of their device to match an authorized one, thereby gaining unauthorized access to the network. This susceptibility to MAC address spoofing makes MAC-Auth a weaker security mechanism compared to more robust authentication methods like 802.1X, which involves mutual authentication and encryption protocols.

The scenario involves an AOS-8 Mobility Controller (MC) with Control Plane Security (CPSec) enabled and auto certificate provisioning disabled. CPSec is a feature that secures the control plane communication between the MC and APs using certificates. When CPSec is enabled, APs must be authorized and trusted by the MC to become managed.

CPSec Enabled, Auto Cert Provisioning Disabled: When CPSec is enabled, APs must have a valid certificate to establish a secure control plane connection with the MC. If auto certificate provisioning is disabled (as shown in the exhibit), the MC does not automatically provision certificates to the APs. Instead, the APs must already have a factory-installed certificate (or a manually installed certificate), and the MC must trust the AP’s certificate by having the issuing CA in its trust list. Additionally, the AP must be on the MC’s AP whitelist to be authorized.

AP Whitelist: The AP whitelist is a list of authorized APs maintained on the MC (or Mobility Master, MM, if present). For an AP to become managed, its MAC address must be in the whitelist, especially when CPSec is enabled and auto provisioning is disabled. This ensures that only authorized APs can connect to the MC.

Option A, "Installing CA-signed certificates on the APs," is incorrect because HPE Aruba Networking APs, such as the 335 series, come with factory-installed certificates signed by Aruba’s CA. These certificates are sufficient for CPSec, provided the MC trusts the Aruba CA (which is typically preconfigured). Manually installing CA-signed certificates is not required unless the factory certificates are not used or trusted.

Option B, "Approving the APs as authorized APs on the AP whitelist," is correct. With CPSec enabled and auto cert provisioning disabled, the APs must be explicitly authorized by adding their MAC addresses to the AP whitelist on the MC. This step ensures that the MC accepts the AP’s certificate and allows it to become managed.

Option C, "Installing self-signed certificates on the APs," is incorrect because self-signed certificates are not typically used for CPSec. APs use factory-installed certificates, and the MC must trust the issuing CA. Self-signed certificates would require manual trust configuration on the MC, which is not a standard practice.

Option D, "Configuring a PAPI key that matches on the APs and MCs," is incorrect. PAPI (Protocol for AP Provisioning and Information) keys are used for securing communication between APs and the MC in non-CPSec environments or for specific configurations (e.g., when CPSec is disabled). When CPSec is enabled, certificate-based authentication replaces the need for a PAPI key.

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

"When Control Plane Security (CPSec) is enabled and auto certificate provisioning is disabled, APs must be authorized by adding their MAC addresses to the AP whitelist on the Mobility Controller (or Mobility Master). The AP uses its factory-installed certificate to establish a secure control plane connection with the MC. The MC must trust the CA that issued the AP’s certificate (e.g., Aruba’s CA), and the AP must be in the whitelist to become managed. To add an AP to the whitelist, navigate to Configuration > Access Points > AP Whitelist in the MC UI and add the AP’s MAC address." (Page 395, CPSec Configuration Section)

Additionally, the HPE Aruba Networking CPSec Deployment Guide notes:

"If auto cert provisioning is disabled, the AP whitelist becomes mandatory for CPSec. Each AP must be explicitly approved by adding its MAC address to the whitelist, ensuring that only authorized APs can connect to the MC. The AP’s factory certificate is used for authentication, and no manual certificate installation is required on the AP." (Page 12, CPSec with Manual Provisioning Section)

HPE Aruba Networking ClearPass Policy Manager (CPPM) uses device profiling to identify and classify endpoints on the network, enabling granular access control based on device type, OS, or other attributes. CPPM supports both passive and active profiling methods.

Option C, "CPPM can analyze settings such as TTL and time window size in endpoints' TCP traffic in order to fingerprint the OS," is correct. TCP fingerprinting is a passive profiling method used by CPPM. It involves analyzing TCP packet headers, such as the Time To Live (TTL) value and TCP window size, which vary between operating systems (e.g., Windows, Linux, macOS). CPPM captures this traffic (e.g., via mirrored traffic from a switch or controller) and matches the TCP attributes against its fingerprint database to identify the OS of the endpoint.

Option A, "CPPM can use Wireshark to actively probe devices, analyze their traffic patterns, and construct an endpoint profile," is incorrect. CPPM does not use Wireshark for profiling; Wireshark is a third-party packet analysis tool. CPPM has its own built-in profiling engine and does not rely on external tools like Wireshark for active probing.

Option B, "CPPM can use SNMP to configure Aruba switches and mobility devices to mirror client traffic to CPPM for analysis," is incorrect. While CPPM can receive mirrored traffic for profiling (e.g., via SPAN or mirror ports), it does not use SNMP to configure the mirroring. The configuration of traffic mirroring is typically done manually on the switch or controller (e.g., using a datapath mirror on an MC), not via SNMP by CPPM.

Option D, "CPPM can analyze settings such as TCP/UDP ports used for HTTP, DHCP, and DNS in endpoints' traffic to fingerprint the OS," is incorrect. While CPPM does analyze HTTP, DHCP, and DNS traffic for profiling, it does not fingerprint the OS based on TCP/UDP ports. Instead, it uses attributes like DHCP Option 55 (for DHCP fingerprinting) or HTTP User-Agent strings (for HTTP fingerprinting) to identify devices, not the ports themselves.

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

"ClearPass supports TCP fingerprinting as a passive profiling method to identify the operating system of endpoints. By analyzing TCP packet headers, such as the Time To Live (TTL) value and TCP window size, ClearPass can fingerprint the OS of a device. For example, Windows devices typically have a TTL of 128, while Linux devices often have a TTL of 64. These attributes are matched against ClearPass’s fingerprint database to classify the device." (Page 248, TCP Fingerprinting Section)

Additionally, the ClearPass Device Insight Data Sheet notes:

"ClearPass uses passive profiling techniques like TCP fingerprinting to identify device operating systems. By examining TCP attributes such as TTL and window size, ClearPass can accurately determine whether a device is running Windows, Linux, macOS, or another OS, enabling precise policy enforcement." (Page 3, Profiling Methods Section)