HPE6-A84 Aruba Certified Network Security Expert Written Exam Questions and Answers

This is because a parameter is a variable that can be defined and modified by the user or the script, and can be used to customize the behavior and output of the NAE script. A parameter can be referred to by using the syntax self ^ramsfname], where ramsfname is the name of the parameter.

By defining a parameter for the value, the developer can make the NAE script more flexible and adaptable to different scenarios and switches. The parameter can be set to a default value, such as 10, but it can also be changed by the user or the script based on the network conditions and requirements. For example, the parameter can be adjusted dynamically based on the average or standard deviation of the number of rejects per hour, or based on the feedback from the user or other admins. This way, the NAE script can trigger an alert only when the number of rejects is truly unusual and not just arbitrary.

A. Checking one of the access switches’ RADIUS statistics and adding 10 to the number listed for rejects. This is not a good recommendation because it does not account for the variability and diversity of the network environment and switches. The number of rejects listed for one switch might not be representative or relevant for another switch, as different switches might have different traffic patterns, client types, RADIUS configurations, etc. Moreover, adding 10 to the number of rejects is an arbitrary and fixed value that might not reflect the actual threshold for triggering an alert.

B. Defining a baseline and referring to it for the value. This is not a bad recommendation, but it is not as good as defining a parameter. A baseline is a reference point that represents the normal or expected state of a network metric or performance indicator. A baseline can be used to compare and contrast the current network situation and detect any anomalies or deviations. However, a baseline might not be easy or accurate to define, as it might require historical data, statistical analysis, or expert judgment. Moreover, a baseline might not be stable or constant, as it might change over time due to network growth, evolution, or optimization.

C. Using 10 (per hour) as a good starting point for the value. This is not a good recommendation because it is an arbitrary and fixed value that might not reflect the actual threshold for triggering an alert. Using 10 (per hour) as the value might result in false positives or false negatives, depending on the network conditions and switches. For example, if the normal number of rejects per hour is 5, then using 10 as the value might trigger an alert too frequently and unnecessarily. On the other hand, if the normal number of rejects per hour is 15, then using 10 as the value might miss some important alerts and risks.

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.

The exhibit shows a screenshot of a Malwarebytes alert that indicates that a website was blocked due to compromise. The alert contains the following information:

• The type of protection: Web Protection
• The website that was blocked: 10.254.1.21
• The port that was used: 80
• The process that initiated the connection: C:\Program Files (x86)\Google\Chrome\Application\chrome.exe
• The IP address of the device that initiated the connection: 10.1.26.151

The IP address of the device that initiated the connection is the one that should be recorded as a possibly compromised client, as it indicates that the device tried to access a malicious website that could infect it with malware or steal its data. In this case, the IP address of the possibly compromised client is 10.1.26.151.

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

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.

According to the Aruba Cloud Authentication and Policy Overview1, Device Insight tags are stored in the Endpoint Repository and can be used as conditions within CPPM role mapping or enforcement policy rules. The rule condition type should be Endpoint, and the attribute should be Device Insight Tags. No extra authorization source is required for services that use policies with these rules. Therefore, option D is the correct answer.

Option A is incorrect because creating an HTTP authentication source to the Central API is not necessary to use Device Insight tags as conditions. Device Insight tags are already synchronized between Central and CPPM, and can be accessed from the Endpoint Repository.

Option B is incorrect because using the Application type for the rule conditions is not applicable to Device Insight tags. The Application type is used to match attributes from the Application Authentication source, which is used to integrate with third-party applications such as Microsoft Intune or Google G Suite.

Option C is incorrect because using the Endpoints Repository type for the rule conditions is not valid for Device Insight tags. The Endpoints Repository type is used to match attributes from the Endpoints Repository source, which is different from the Endpoint type. The Endpoints Repository source contains information about endpoints that are manually added or imported into CPPM, while the Endpoint type contains information about endpoints that are dynamically discovered and profiled by CPPM or Device Insight. Adding Endpoints Repository as a secondary authentication source for services that use policies with these rules is also unnecessary and redundant.

Aruba Central can provide visibility and profiling of clients using the Client Insights feature, which is an AI-powered solution that uses native infrastructure telemetry to identify and classify clients based on their OS and general category. This feature does not require any additional hardware or software, such as gateways, IP helpers, or packet sniffers. It works by collecting and analyzing data from the Aruba APs and AOS-CX switches that are managed by Aruba Central. You can find more information about Client Insights in the Visibility and profiling solutions | HPE Aruba Networking page and the Clients Profile - Aruba page.

Aruba Central supports site-to-site VPNs between AOS 10 gateways, which are Aruba devices that provide routing, firewall, and VPN functions. Aruba Central can automatically provision and manage the site-to-site VPNs using the VPN Manager feature. The VPN Manager allows you to create VPN groups that consist of one or more hubs and branches, and define the VPN settings for each group1

Aruba Central uses IPsec as the protocol to secure the site-to-site connections between the AOS 10 gateways. IPsec is a standard protocol that provides encryption, authentication, and integrity for IP packets. Aruba Central automatically establishes IPsec tunnels for all site-to-site connections using keys that are securely distributed by Central. The keys are generated by Central and pushed to the gateways using a secure channel. The keys are rotated periodically to enhance security2

This is because ARP inspection is a security feature that validates ARP packets in a network and prevents ARP poisoning attacks12 ARP inspection works by intercepting, logging, and discarding ARP packets with invalid IP-to-MAC address bindings1 To enable ARP inspection, the switch needs to know which ports are trusted and which are untrusted. Trusted ports are those that connect to authorized DHCP servers or other network devices that are not vulnerable to ARP spoofing. Untrusted ports are those that connect to end hosts or devices that might send forged ARP packets13

In the exhibit, LAG 1 is configured as a trusted port for ARP inspection, which is correct because it connects to the core switch. However, the edge ports (1/1/1-1/1/24) are not configured as untrusted ports for ARP inspection, which is incorrect because they connect to end hosts that might be compromised by an attacker. By default, all ports are untrusted for ARP inspection, but this can be changed by using the command ip arp inspection trust on the interface configuration mode3 Therefore, to protect VLAN 4 against ARP poisoning, the edge ports should be configured as untrusted for ARP inspection by using the command no ip arp inspection trust on the interface configuration mode. This way, the switch will validate the ARP packets received on these ports against the DHCP snooping database or an ARP access-list and drop any invalid packets34

A. ARP proxy is not enabled on VLAN 4. This is not an issue because ARP proxy is an optional feature that allows the switch to respond to ARP requests on behalf of hosts in different subnets5 It is not related to ARP poisoning or ARP inspection.

B. LAG 1 is configured as trusted for ARP inspection but should be untrusted. This is not an issue because LAG 1 connects to the core switch, which is a trusted device that does not send forged ARP packets.

C. DHCP snooping is not enabled on VLAN 4. This is not an issue because DHCP snooping is a separate feature that prevents rogue DHCP servers from offering IP addresses to clients6 It is not directly related to ARP poisoning or ARP inspection, although it can provide information for ARP inspection validation if enabled

This is because a parameter is a variable that can be defined and modified by the user or the script, and can be used to customize the behavior and output of the NAE script. A parameter can be referred to by using the syntax self ^ramsfname], where ramsfname is the name of the parameter.

By defining a parameter for the RADIUS server, you can make the NAE script more flexible and adaptable to different scenarios and switches. The parameter can be set to a default value, such as cp.acnsxtest.local, but it can also be changed by the user or the script based on the network conditions and requirements. For example, the user can select a different hostname or IP address for the monitored RADIUS server when they create an agent from the script, or the script can automatically detect and update the parameter based on the switch configuration. This way, the NAE script can monitor statistics from any RADIUS server defined on the switch without hard-coding the server name or IP address in the monitor URI.

A. Use this variable, %{radius-ipV when defining the monitor URI in the NAE agent script. This is not a valid recommendation because %{radius-ipV is not a valid variable in NAE scripts. Variables in NAE scripts are prefixed with self ^ramsfname], not with %. Moreover, radius-ipV is not a predefined variable that contains the RADIUS server name or IP address, but rather a generic term that could refer to any IP version.

C. Use a callback action to collect the name of any RADIUS servers defined on the switch at the time the agent is created. This is not a bad recommendation, but it is not as good as defining a parameter. A callback action is a feature that allows an NAE script to execute a command on the switch and collect its output for further processing or display. A callback action can be used to collect the name of any RADIUS servers defined on the switch by executing a command such as show radius-server or show running-config radius-server and parsing its output. However, a callback action might not be as fast or reliable as using a parameter, as it depends on the availability and responsiveness of the switch and its CLI.

D. Make the script editable so that admins can edit it on demand when they are creating scripts. This is not a good recommendation because making the script editable exposes it to potential errors or modifications that could affect its functionality or performance. Making the script editable also requires more effort and expertise from the admins, who might not be familiar with NAE scripting syntax or logic. Moreover, making the script editable does not future proof it, as it does not allow for dynamic changes or updates based on network conditions or requirements.

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The correct answer is B. Create a new VLAN on the AOS-CX switch and configure that VLAN as the UBT client VLAN.

User-based tunneling (UBT) is a feature that allows the AOS-CX switches to tunnel the traffic from wired clients to a mobility gateway cluster, where they can be assigned a role and a VLAN based on their authentication and authorization 1. To enable UBT, the switches need to have a UBT zone configured with the IP addresses of the gateways, and a UBT client VLAN configured with the ubt-client-vlan command 2.

The UBT client VLAN is a special VLAN that is used to encapsulate the traffic from the tunneled clients before sending it to the gateways. The UBT client VLAN must be different from any other VLANs used on the switch or the network, and it must not be assigned to any ports or interfaces on the switch 2. The UBT client VLAN is only used internally by the switch for UBT, and it is not visible to the clients or the gateways.

In this scenario, the customer wants to tunnel the clients that pass user authentication to the gateway cluster, where they will be assigned to VLAN 20. Therefore, the switch must have a UBT client VLAN configured that is different from VLAN 20 or any other VLANs on the network. For example, the switch can use VLAN 4000 as the UBT client VLAN, as shown in one of the web search results 3. The switch must also have a UBT zone configured with the system IP addresses of the gateways as the primary and backup controllers, as explained in question 3.

The other options are not correct or relevant for this issue:

• Option A is not correct because assigning VLAN 20 as the access VLAN on any edge ports to which tunneled clients might connect would conflict with UBT. The access VLAN is the VLAN that is assigned to untagged traffic on a port, and it is used for local switching on the switch 4. If VLAN 20 is assigned as the access VLAN, then the traffic from the clients will not be tunneled to the gateways, but rather switched locally on VLAN 20. This would defeat the purpose of UBT and cause inconsistency in role and VLAN assignment.
• Option C is not correct because VIA licenses are not required for UBT. VIA licenses are required for enabling VPN services on Aruba Mobility Controllers for remote access clients using Aruba Virtual Intranet Access (VIA) software . VIA licenses are not related to UBT or wired clients.
• Option D is not correct because changing the port-access auth-mode mode to client-mode on any edge ports to which tunneled clients might connect would not affect UBT. The port-access auth-mode mode determines how a port handles authentication requests from multiple clients connected to a single port . Client-mode is the default mode that allows only one client per port, while multi-client-mode allows multiple clients per port. The port-access auth-mode mode does not affect how UBT works or how traffic is tunneled from a port.

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