HPE6-A84 Questions and Answers

RF Protect is a feature that enables wireless intrusion detection and prevention system (WIDS/WIPS) capabilities on AOS 8-based solutions. WIDS/WIPS allows detecting and mitigating rogue APs, unauthorized clients, and other wireless threats. RF Protect requires RF Protect licenses to be installed and WIDS to be enabled on the Mobility Master (MM).

To use the built-in capabilities of APs for WIDS/WIPS, without deploying dedicated air monitors (AMs), admins need to set at least one radio on each AP to air monitor mode. Air monitor mode allows the AP to scan the wireless spectrum and report any wireless activity or anomalies to the MM. Air monitor mode does not affect the other radio on the AP, which can still serve clients in access mode. By setting at least one radio on each AP to air monitor mode, admins can achieve full coverage and visibility of the wireless environment and detect rogue APs.

If admins do not set any radio on the APs to air monitor mode, the APs will not scan the wireless spectrum or report any wireless activity or anomalies to the MM. This means that the APs will not be able to detect rogue APs, even if they are connected to the same network. Therefore, admins should check whether they have set at least one radio on each AP to air monitor mode.

DNS tunneling is a technique that abuses the DNS protocol to tunnel data or commands between a compromised host and an attacker’s server. DNS tunneling can be used to establish a command and control channel, which allows the attacker to remotely control the malware or exfiltrate data from the infected host1

The traffic capture in the exhibit shows some signs of DNS tunneling. The source IP address is 10.1.7.2, which is likely an internal host behind a firewall. The destination IP address is 8.8.8.8, which is a public DNS resolver. The DNS queries are for subdomains of badsite.com, which is likely a malicious domain registered by the attacker. The subdomains have long and random names, such as 0x2a0x2a0x2a0x2a0x2a0x2a0x2a0x2a.badsite.com, which could be used to encode data or commands. The DNS responses have large sizes, such as 512 bytes, which could be used to carry data or commands back to the host2

 This is because an Endpoint Context Server (ECS) is a feature that allows ClearPass to receive contextual information from external sources, such as Aruba Central, and use it for policy enforcement and reporting. An ECS can be configured to point to the Aruba Central API and fetch data such as device type, category, OS, applications, traffic flows, etc.

An ECS can be used to communicate the information that an IoT client has used SSH to Aruba ClearPass Policy Manager (CPPM). The ECS can query the Aruba Central API and retrieve the network traffic flows of the wireless IoT devices that are categorized as “Raspberry Pi” clients. The ECS can then filter the traffic flows by the SSH protocol and send the relevant information to CPPM. CPPM can then use this information for policy decisions, such as allowing or denying SSH access, or triggering alerts or actions.

B. On CPPM enable Device Insight integration. This is not a valid step because Device Insight is a feature that allows ClearPass to discover, profile, and fingerprint devices on the network using deep packet inspection (DPI) and machine learning (ML). Device Insight does not communicate with Aruba Central or receive information from it. Moreover, Device Insight might not be able to detect SSH traffic on encrypted wireless IoT devices without decrypting it first.

C. On Central configure APs and gateways to use CPPM as the RADIUS accounting server. This is not a valid step because RADIUS accounting is a feature that allows network devices to send periodic updates about the status and activity of authenticated users or devices to a RADIUS server, such as CPPM. RADIUS accounting does not communicate with Aruba Central or receive information from it. Moreover, RADIUS accounting might not be able to capture SSH traffic on wireless IoT devices without inspecting it first.

D. On Central set up CPPM as a Webhook application. This is not a valid step because Webhook is a feature that allows Aruba Central to send notifications or events to external applications or services using HTTP requests. Webhook does not communicate with CPPM or send information to it. Moreover, Webhook might not be able to send SSH traffic information on wireless IoT devices without filtering it first.

BPDU (Bridge Protocol Data Unit) is a message that is exchanged between switches to maintain the spanning tree topology and prevent loops. BPDU protection and BPDU filtering are two features that can be configured on AOS-CX switch ports to enhance security and performance.

BPDU protection is a feature that disables a port if it receives a BPDU, indicating that an unauthorized switch or device has been connected to the port. BPDU protection is typically used on edge ports, which are ports that connect to end devices such as PCs or printers, and are not expected to receive BPDUs. BPDU protection prevents rogue devices from connecting to the network and affecting the spanning tree topology.

BPDU filtering is a feature that prevents a port from sending or receiving BPDUs, effectively isolating the port from the spanning tree topology. BPDU filtering is typically used on inter-switch ports, which are ports that connect to other switches, for specialized use cases such as creating a separate spanning tree domain or reducing the overhead of BPDUs. BPDU filtering should be used with caution, as it can create loops or inconsistencies in the network.

You can find more information about how to configure BPDU protection and BPDU filtering on AOS-CX switch ports in the [Configuring Spanning Tree Protocol - Aruba] page and the [AOS-CX Switching Configuration Guide] page. The other options are not correct because they either use BPDU protection or BPDU filtering on the wrong type of ports or for the wrong purpose. For example, using BPDU protection on inter-switch ports would disable the ports if they receive BPDUs, which are expected in normal operation. Using BPDU filtering on edge ports would allow rogue devices to connect to the network and create loops or affect the spanning tree topology.

According to the ClearPass Policy Manager User Guide1, the tag shown in the exhibit is a Device Insight tag, which is used to classify and identify devices based on their behavior and characteristics. Device Insight tags can be used as conditions in enforcement policies to apply different actions or roles to devices based on their tags. However, in order to ensure that devices are reclassified and receive the correct treatment based on their tags, profiling must be enabled in each service that uses one of these enforcement profiles. Profiling is a feature that allows ClearPass to dynamically discover and profile devices on the network, and update their attributes and tags accordingly. Profiling also allows ClearPass to send RADIUS Change of Authorization (CoA) messages to the network access servers (NASes) that control the access of the devices, and instruct them to reauthenticate or terminate the sessions of the devices that have changed their tags. The profiling action must be set to the correct one for the NASes using that service, as different NASes may support different types of CoA messages. Therefore, option C is the correct answer.

An authentication source is a configuration element in CPPM that defines how to connect to an external identity provider and retrieve user or device information . CPPM supports various types of authentication sources, such as Active Directory, LDAP, SQL, Kerberos, and HTTP .

To authenticate wireless and wired clients to Azure AD, you need to set up an authentication source as HTTP type, referencing Azure AD’s FQDN . This type of authentication source allows CPPM to use REST API calls to communicate with Azure AD and validate the user or device credentials . You also need to configure the OAuth 2.0 settings for the authentication source, such as the client ID, client secret, token URL, and resource URL .

To use information collected by Intune to make access control decisions, you need to set up another authentication source as HTTP type, referencing the Intune extension . This type of authentication source allows CPPM to use REST API calls to communicate with Intune and retrieve the device compliance status . You also need to configure the OAuth 2.0 settings for the authentication source, such as the client ID, client secret, token URL, and resource URL .

A profile conflict occurs when ClearPass Policy Manager (CPPM) detects a change in the device category or OS family of an endpoint that has been previously profiled. This could indicate that someone has spoofed the MAC address of a legitimate device and is trying to gain unauthorized access to the network. For example, if an endpoint that was previously profiled as a Printer suddenly shows a new profile of Computer, this could be a sign of an attack. You can find more information about profile conflicts and how to resolve them in the ClearPass Policy Manager User Guide1. The other options are not necessarily signs of unauthorized access, as they could have other explanations. For example, multiple DHCP options under the fingerprints could indicate that the device has connected to different networks or subnets, an Unknown status could indicate that the device has not been authenticated yet, and a lack of hostname or a random hostname could indicate that the device has not been configured properly or has been reset to factory settings.

This is because a downloadable user role (DUR) is a feature that allows the switch to use a central ClearPass server to download user-roles to the switch for authenticated users12 A DUR can contain various attributes and rules that define the access level and privileges of the user, such as VLAN, ACL, PoE, reauthentication period, etc3 A DUR can also be customized and updated on the ClearPass server without requiring any changes on the switch1

A DUR can be used to create a “provision” role that allows users to enroll new wired clients in Intune. The “provision” role can have limited access that only lets them enroll and receive certificates from the Intune service. The “provision” role can also have rules that restrict the Internet access of the users to only the necessary sites, such as the Intune portal and the certificate authority. The rules can be based on IPv4 or IPv6 addresses, depending on the network configuration and preference2

A. Configuring the rules for the “provision” role with IPv6 addresses, which tend to be more stable. This is not a valid recommendation because it does not address how to create and apply the “provision” role on the switch. Moreover, IPv6 addresses do not necessarily tend to be more stable than IPv4 addresses, as both protocols have their own advantages and disadvantages4

B. Enabling tunneling to the MCs on the “provision” role and then setting up the privileges on the MCs. This is not a valid recommendation because it does not explain how to enable tunneling or what MCs are. Moreover, tunneling is a technique that encapsulates one network protocol within another, which adds complexity and overhead to the network communication5

D. Assigning the “provision” role to a VLAN and then setting up the rules within a Layer 2 access control list (ACL). This is not a valid recommendation because it does not explain how to assign a role to a VLAN or how to create a Layer 2 ACL on the switch. Moreover, a Layer 2 ACL is limited in its filtering capabilities, as it can only match on MAC addresses or Ethernet types, which might not be sufficient for restricting Internet access to specific sites

To configure user-based tunneling (UBT) on an AOS-CX switch, you need to specify the IP addresses of the mobility gateways that will receive the tunneled traffic from the switch 1. The primary controller is the preferred gateway for the switch to establish a tunnel, and the backup controller is the alternative gateway in case the primary controller fails or becomes unreachable 1. The IP addresses of the gateways should be their system IP addresses, which are used for inter-controller communication and cluster discovery 2.

In this scenario, the customer has a gateway cluster with two gateways, each with a system IP address on VLAN 4085. Therefore, the switch should use these system IP addresses as the primary and backup controllers for UBT. The IP addresses of the gateways on VLAN 20 and VLAN 4094 are not relevant for UBT, as they are used for user traffic and WAN connectivity, respectively 2. The VRRP IP address on VLAN 20 is also not applicable for UBT, as it is a virtual IP address that is not associated with any specific gateway 3.

Therefore, the best option is to use 10.20.4.21 as the primary controller and 10.20.4.22 as the backup controller for UBT on the switch. This will ensure high availability and cluster discovery for the tunneled traffic from the switch to the gateway cluster 12.

The UBT solution requires that the edge ports on the switches are configured in VLAN trunk mode, not access mode. This is because the UBT solution uses a special VLAN (VLAN 4095 by default) to encapsulate the user traffic and tunnel it to the gateway. The edge ports need to allow this VLAN as well as any other VLANs that are used for management or control traffic. Therefore, the edge ports should be configured as VLAN trunk ports and allow the necessary VLANs1

To configure CPPM to collect information from Intune on demand during the authentication process, you need to use the Intune extension for ClearPass. This extension allows ClearPass to query Intune for device compliance and configuration information using the Intune API. To use this extension, you need to register an app in Azure AD and grant it the required permissions to access Intune1

The Intune extension uses the device ID as the key to query Intune for device information. The device ID is a unique identifier that is assigned by Intune to each enrolled device. The device ID can be obtained from the client certificate that is used for EAP-TLS authentication. Therefore, the certificates issued to clients must include the Intune ID in the subject name, so that ClearPass can extract it and use it to query Intune2

The certificates issued to clients do not need to be issued by a well-known, trusted CA, as long as ClearPass trusts the CA that issued them. The certificates do not need to include the client MAC address in the subject name, as this is not relevant for querying Intune. The certificates do not need to be issued by a ClearPass Onboard CA, as this is not a requirement for using the Intune extension.