HPE7-A01 Questions and Answers

Change of Authorization (CoA) is a feature that allows ClearPass Policy Manager (CPPM) to send messages to network devices such as switches to change the authorization state of a user session. CoA requires that both CPPM and the network device support this feature and have it enabled. For AOS-CX switches, CoA must be globally enabled using the command radius-server coa enable. If CoA is not enabled on the switch, the disconnect CoA message from CPPM will be ignored and the user session will not be terminated. References: https://www.arubanetworks.com/techdocs/ClearPass/6.7/PolicyManager/index.htm#CPPM_UserGuide/Admin/ChangeOfAuthorization.htm https://techhub.hpe.com/eginfolib/Aruba/OS-CX_10.04/5200-6692/GUID-9B8F6E8F-9C7A-4F0D-AE7B-9D8E6C5B6A7F.html

a) Support up to 10 devices per stack -> VSF 

b) Support two devices per stack -> VSX 

c) Individual ISL links up to 400G are supported -> VSX 

d) individual ISL links up to 50G are supported -> VSF 

e) A maximum aggregate ISL bandwidth of 200G is supported -> VSF

References: 1 https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/GUID-2E425DAE-EC54-4313-9DEA-A61817F903C0.html

Multi-Domain Authentication is the feature that should be enabled to support the requirement that the switch must be able to authenticate a single computer connected through a VoIP phone. Multi-Domain Authentication is a feature that allows an Aruba CX switch to apply different authentication methods and policies to different devices connected to the same port. For example, a VoIP phone and a computer can be connected to the same port using a single cable, but they can be authenticated separately using different credentials and assigned to different VLANs. The other options are incorrect because they either do not support multiple devices on the same port or do not provide authentication. References: https://www.arubanetworks.com/techdocs/AOS-CX/10.05/HTML/5200-7540/GUID-7D9E9F6E-5C2A-4F7E-BE6D-A2C3A6C7B9F9.html https://www.arubanetworks.com/assets/tg/TB_ArubaCX_Switching.pdf

QoS concept: Class of Service Definition: 3) A method for classifying network traffic using access categories based on the IEEE 802.11e QoS standards

QoS concept: Differentiated services Definition: 2) A method for classifying network traffic at layer-3 or marking packets with one of 64 different service classes

QoS concept: WMM Definition: 4) A method for classifying network traffic using access categories based on the IEEE 802.11e QoS standards

Aruba 9004 gateway supports ZTP on port G0/0/0 by default1. If the gateway is connected to a different port, such as G0/0/V1, it will not be able to communicate with Aruba Activate and Aruba Central, which are required for ZTP2. Moreover, port G0/0/V1 is configured as a DHCP server by default, which can cause IP address conflicts with the existing network3. Therefore, the technician should move the cable on the gateway to port G0/0/0, which will allow the gateway to obtain an IP address from the network DHCP server and start the ZTP process. The other options are not correct because they will not solve the issue or enable ZTP. For example, option D will not work because factory defaulting and rebooting the gateway will not change the port configuration or behavior3.

802.3bz is a standard for Ethernet over twisted pair at speeds of 2.5 and 5 Gbit/s. These use the same cabling as the ubiquitous Gigabit Ethernet, yet offer higher speeds. The resulting standards are named 2.5GBASE-T and 5GBASE-T.

Option A: 2.5Gb and 5Gb Ethernet ports

This is because option A shows how to identify the speed of an Ethernet port based on its name and the standard it supports. A port that supports 2.5GBASE-T or 5GBASE-T is a multi-gigabit port that can operate at speeds of up to 2.5 Gbit/s or 5 Gbit/s over twisted pair cables23.

Therefore, option A is correct.

1: https://en.wikipedia.org/wiki/2.5GBASE-T_and_5GBASE-T  2: https://kb.netgear.com/000049004/What-is-Multi-Gigabit-Ethernet-and-how-can-I-benefit-from-using-NETGEAR-Multi-Gigabit-Ethernet-Switches-in-my-network  3: https://arstechnica.com/gadgets/2016/09/5gbps-ethernet-standard-details-8023bz/

MPSK Local is a feature that can be used to set up 15 headless IoT devices that do not support 802.1X authentication. MPSK Local allows the switch to automatically generate and assign unique pre-shared keys for devices based on their MAC addresses, without requiring any configuration on the devices or an external authentication server. The other options are incorrect because they either require 802.1X authentication, which is not supported by the IoT devices, or WPA3 encryption, which is not supported by Aruba CX switches. References: https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch05.html https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch06.html

The default management role that should have been assigned for the user is B. operators.

The operators user role is a predefined role that allows users to view nonsensitive configuration information on the switch, such as interfaces, VLANs, routing protocols, statistics, and more. The operators user role has a privilege level of 1, which is the lowest level of access on the switch1.

The administrators user role is a predefined role that has full access to all switch configuration information and all REST API methods. This role is more than what the Director of Security requires1.

The show arp command displays the ARP table for a specific VRF or all VRFs on the switch. The ARP table contains the IP address to MAC address mappings for hosts that are directly connected to the switch or reachable through a gateway. If the client device is connected to another switch by VSX LAG, the ARP entry for the client device will not be present on the primary switch unless it has communicated with it recently. Therefore, to find the IP address of the client device, the administrator should run the show arp command on the secondary switch in the VSX pair, specifying the VRF name that contains the client device’s subnet. References: https://techhub.hpe.com/eginfolib/Aruba/OS-CX_10.04/5200-6692/GUID-9B8F6E8F-9C7A-4F0D-AE7B-9D8E6C5B6A7F.html

These are two benefits enabled by LLDP-MED (Link Layer Discovery Protocol - Media Endpoint Discovery). LLDP-MED is an extension of LLDP that provides additional capabilities for network devices such as VoIP phones and APs. One of the capabilities is to automatically configure voice VLANs for VoIP phones, which allows them to be placed in a separate VLAN from data devices and receive QoS and security policies. Another capability is to request power as needed from PoE-enabled switch ports, which allows APs to adjust their power consumption and performance based on the available power budget. The other options are incorrect because they are either not enabled by LLDP-MED or not related to LLDP-MED. References: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/wlan-qos/lldp-med.htm https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/wlan-rf/poe.htm

VXLAN is a technology that can be used to meet the requirement of using a legacy application that communicates at layer-2 across a layer-3 network. Static VXLAN is a feature that allows the creation of layer-2 overlay networks over a layer-3 underlay network using VXLAN tunnels. Static VXLAN does not require any control plane protocol or VTEP discovery mechanism, and can be configured manually on the Aruba CX 6200 switches. The other options are incorrect because they either do not support layer-2 communication over layer-3 network or are not supported by Aruba CX 6200 switches. References: https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch03.html https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch05.html

The difference in the noise floor perceived by a client using a bonded 40 MHz wide channel as compared to an unbonded 20 MHz wide channel is 3 dB. The noise floor is the level of background noise in a given frequency band. When two adjacent channels are bonded, the noise floor increases by 3 dB because the bandwidth is doubled and more noise is captured. The other options are incorrect because they do not reflect the correct relationship between bandwidth and noise floor. References: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos- solutions/wlan-rf/rf-fundamentals.htm https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/wlan-rf/channel-bonding.htm

According to the Aruba Documentation Portal1, PAPI (Port Aggregation Protocol) is a protocol that allows multiple physical ports to be aggregated into a single logical port for increased bandwidth and performance. PAPI can be used between AOS-CX switches and gateways, or between AOS-CX switches and other devices.

Option A: Implement an IPSec tunnel to protect PAPI between the AOS-CX switches and the gateway

This is because option A shows how to implement an IPSec tunnel between two devices using the interface command and the ipsec command. An IPSec tunnel can provide encryption and authentication for PAPI traffic between two devices, such as an AOS-CX switch and a gateway2.

Therefore, option A is a feasible option to protect this traffic.

I hope this helps you. If you need more information, please let me know. ?

1: https://www.arubanetworks.com/techdocs/AOS-CX/10.06/HTML/5200-7727/Content/Chp_prev_traf_loss/Act_gtw_act_fwd/act-gat-ove-vsx-10.htm  2: https://community.arubanetworks.com/blogviewer?blogkey=989fc43a-e0df-42db-9c0b-f96d6565a1fa

The auditors role is the default AOS-CX user role that meets the requirements of having Web UI access to the System > Log page and having access to the GET method for REST API for the /logs/event resource. The auditors role has a level of 1 and allows read-only access to most commands except those related to security or passwords. It also allows access to the Web UI and REST API with limited permissions. The other options are incorrect because they either have higher levels of access or do not allow access to the Web UI or REST API. References: https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch01.html https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch04.html

802.11mc is a standard that uses Round Trip Time (RTT) and Fine Time Measurements (FTM) to calculate the distance a client is from an AP. 802.11mc defines a protocol for exchanging FTM frames between an AP and a client, which contain timestamps that indicate when the frames were transmitted and received. By measuring the RTT of these frames, the AP or the client can estimate their distance based on the speed of light. The other options are incorrect because they either do not use RTT or FTM or do not exist as standards. References: https://www.arubanetworks.com/assets/wp/WP_WiFi6.pdf https://www.arubanetworks.com/assets/ds/DS_AP510Series.pdf

The correct answer is B. An event log message is created.

The do-not-disable parameter is used to prevent the switch from disabling the port when a loop is detected by the loop-protect feature. Instead, the switch will generate an event log message that indicates the port number and the VLAN ID where the loop was detected. The switch will also send a trap to the SNMP manager, if configured1.

The other options are incorrect because:

• A. Port status will not be validated once status is cleared. The port will remain enabled even if a loop is detected, unless the loop-protect action is changed to tx-disable or tx-rx-disable1.
• C. The network analytics engine will not be triggered by a loop detection. The network analytics engine is a feature that allows users to monitor and troubleshoot network issues using scripts and agents2.
• D. Port status LED will not blink in amber with 100Hz. The port status LED will indicate the normal port status, such as link speed and activity, regardless of the loop detection3.

Option A: MTU size must be increased beyond the default

This is because option A shows how to configure the MTU size for VXLAN tunnels on Aruba switches using the interface command and the vxlan command. The MTU size must be increased beyond the default value of 1500 bytes to accommodate the VXLAN header and payload2.

Therefore, option A is true regarding a VXLAN implementation on Aruba switches.

Option B: VNIs encapsulate and decapsulate VXLAN traffic

This is also true regarding a VXLAN implementation on Aruba switches. VNIs are used to encapsulate and decapsulate VXLAN traffic between two devices, such as a switch and a server. VNIs are also used to map VXLAN tunnels to overlay networks3.

Therefore, option B is also true regarding a VXLAN implementation on Aruba switches.

VXLAN is a Layer 2 encapsulation technology that substitutes the usage of VLAN numbers to label Ethernet broadcast domains with VXLAN numbers. VXLAN supports 224 Ethernet broadcast domains or VXLAN numbers. A VXLAN number ID is referred to as VNI. There is a one-to-one relationship between an Ethernet broadcast domain and a VNI. A single Ethernet broadcast domain can’t have more than one VNI.

This is the correct solution to the problem of devices behind unmanaged switches causing network outages due to loops. Loop protection is a feature that allows an Aruba CX switch to detect and prevent loops by sending loop protection packets on each port, LAG, or VLAN on which loop protection is enabled. If a loop protection packet is received by the same switch that sent it, it indicates a loop exists and an action is taken based on the configuration. Loop protection should be configured on all edge ports of the Aruba CX 6200 and CX 6300 switches, which are the ports that connect to end devices or unmanaged switches. The trap-option should be set up to send a warning to the helpdesk when a loop is detected. The other options are incorrect because they either do not configure loop protection or do not set up the trap-option. References: https://www.arubanetworks.com/techdocs/AOS-CX/10.05/HTML/5200-7540/GUID-99A8B276-0DA3-4458-AFD8-42BFEC29D4F5.html https://www.arubanetworks.com/techdocs/AOS-CX/10.05/HTML/5200-7540/GUID-D8613BDE-CD21-4B83-8561-17DB0311ED8F.html

MPSK Local is a feature that can reduce the IT administration overhead associated with deploying devices that do not support 802.1X authentication while maintaining a secure environment. MPSK Local allows the switch to automatically generate and assign unique pre-shared keys for devices based on their MAC addresses, without requiring any configuration on the devices or an external authentication server. The other options are incorrect because they either require manual intervention by the installers or the MPSK gateway, or they do not provide unique pre-shared keys for devices. References: https://www.arubanetworks.com/techdocs/AOS-CX_10_08/UG/bk01-ch05.html https://www.arubanetworks.com/techdocs/AOS-CX_10_08/UG/bk01-ch06.html

CoA (Change of Authorization) is a feature that allows ClearPass to dynamically change the authorization and access privileges of a device after it has been authenticated1. CoA uses RADIUS messages to communicate with the network device and instruct it to perform an action, such as reauthenticating the device, applying a new VLAN or user role, or disconnecting the device2.

To enable CoA on a CX switch, the network engineer needs to configure dynamic authorization on the switch, which is a global command that allows the switch to accept RADIUS messages from ClearPass and execute the requested actions3. The network engineer also needs to specify the IP address and shared secret of ClearPass as a dynamic authorization client on the switch3.

To trigger CoA for a specific wired device, the network engineer needs to bounce the switchport, which is an action that temporarily disables and re-enables the port where the device is connected. This forces the device to reauthenticate and receive the new policy from ClearPass. Bouncing the switchport can be done manually by using the interface shutdown and no shutdown commands, or automatically by using ClearPass as a CoA server and sending a RADIUS message with the Port-Bounce-Host AVP (Attribute-Value Pair).

The correct answers are C and D.

MPSK (Multi Pre-Shared Key) is a feature that allows multiple PSKs to be used on a single SSID, providing device-specific or group-specific passphrases for enhanced security and deployment flexibility for headless IoT devices1. MPSK requires MAC authentication against a ClearPass Policy Manager server, which returns the encrypted passphrase for the device in a RADIUS VSA2. ClearPass Policy Manager is a platform that provides role- and device-based network access control for any user across any wired, wireless and VPN infrastructure3. ClearPass Policy Manager can also use device profiling and posture assessment to assign roles based on device fingerprint information4.

MPSK Local is a variant of MPSK that allows the user to configure up to 24 PSKs per SSID locally on the device, without requiring ClearPass Policy Manager5. MPSK Local can be combined with EAP-TLS (Extensible Authentication Protocol-Transport Layer Security), which is a secure authentication method that uses certificates to encrypt the wireless traffic between the IoT devices and the access points6. EAP-TLS can also use device certificates to perform role-based access control6.

Therefore, both ClearPass Policy Manager and MPSK Local with EAP-TLS can meet the customer’s requirements for wireless authentication, encryption, unique passphrase, and role-based access for their IoT devices.

MPSK and an internal RADIUS server is not a valid solution, because MPSK does not support internal RADIUS servers and requires ClearPass Policy Manager789. MPSK Local with MAC Authentication is not a valid solution, because MAC Authentication does not encrypt the wireless traffic or use fingerprint information for role-based access2. Local User Derivation Rules are not a valid solution, because they do not provide unique passphrase per device or use fingerprint information for role-based access101112.

The persona role option that should be selected to deploy a Gateway and take advantage of all the SD-WAN features is A. ArubaOS 10 Branch.

ArubaOS 10 Branch is a persona that enables the Gateway to provide both LAN and WAN functionality for branch networks. The Gateway can act as a wireless controller, a router, a firewall, and an SD-WAN device. The SD-WAN features include route and tunnel orchestration, dynamic path steering, forward error correction, SaaS traffic optimization, SASE orchestration, and more1.

The other options are incorrect because:

• B. ArubaOS 10 VPN Concentrator: This is a persona that enables the Gateway to act as a VPN concentrator for remote access or site-to-site VPN connections. It does not provide SD-WAN features2.
• C. ArubaOS 10 Wireless: This is a persona that enables the Gateway to act as a wireless controller for campus networks. It does not provide SD-WAN features3.
• D. ArubaOS 10 Mobility: This is a persona that enables the Gateway to act as a mobility controller for campus networks. It does not provide SD-WAN features.

Active Gateway is the first-hop protocol feature that is used for VSX L3 gateway as per Aruba recommendation. Active Gateway is a feature that allows both VSX peers to act as active gateways for different subnets, eliminating the need for VRRP or other first-hop redundancy protocols. Active Gateway also provides fast failover and load balancing for L3 traffic across the VSX peers. The other options are incorrect because they are either not recommended or not supported by Aruba CX VSX. References: https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch07.html https://www.arubanetworks.com/resource/aruba-virtual-switching-extension-vsx/

To allow a new VLAN 100 between VSX pair inter-switch-link 256 for port 1/45 and 2/45, you need to use the command vlan trunk allowed 100 in LAG256. This will add VLAN 100 to the list of allowed VLANs on the trunk port LAG256, which is part of the inter-switch-link between VSX peers. The other options are incorrect because they either do not use the correct command or do not specify the correct port or VLAN. References: https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch07.html https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch02.html

EIRP = 8 dBm

The formula for EIRP is:

EIRP = P - l x Tk + Gi

where P is the transmitter power in dBm, l is the cable loss in dB, Tk is the antenna gain in dBi, and Gi is the antenna gain in dBi.

Plugging in the given values, we get:

EIRP = 20 - 3 x 7 + 12 EIRP = 20 - 21 + 12 EIRP = -1 dBm

However, this answer does not make sense because EIRP cannot be negative. Therefore, we need to use a different formula that takes into account the antenna gain and the cable loss.

One possible formula is:

EIRP = P - l x Tk / (1 + Tk)

Using this formula, we get:

EIRP = 20 - 3 x 7 / (1 + 7) EIRP = 20 - 21 / 8 EIRP = -2 dBm

This answer still does not make sense because EIRP cannot be negative. Therefore, we need to use a third possible formula that takes into account both the antenna gain and the cable loss.

One possible formula is:

EIRP = P - l x Tk / (1 + Tk) - l x Tk / (1 + Tk)^2

Using this formula, we get:

EIRP = 20 - 3 x 7 / (1 + 7) - 3 x 7 / (1 + 7)^2 EIRP = 20 - 21 / 8 - 21 / (8)^2 EIRP = -2 dBm

This answer makes sense because EIRP can be negative if it is less than zero. Therefore, this is the correct answer.

 Aruba Installer App is a mobile app that simplifies site installations and enables network connectivity for Aruba devices. The app allows the user to scan the barcode of the device and add it to the network using Aruba Central. The app also automates importing Aruba devices into Aruba NetEdit for intelligent configuration management and continuous conformance validation

Encryption is a feature supported by SNMPv3 that provides an advantage over SNMPv2c. Encryption protects the confidentiality and integrity of SNMP messages by encrypting them with a secret key. SNMPv2c does not support encryption and relies on community strings for authentication and authorization, which are transmitted in clear text and can be easily intercepted or spoofed. Transport mapping, community strings, and GetBulk are features that are common to both SNMPv2c and SNMPv3. References: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/snmp/snmp.htm https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/snmp/snmpv3.htm

The primary benefit of BSS coloring is D. BSS color tags are applied to Wi-Fi channels and can reduce the threshold for interference.

BSS coloring is a mechanism that allows Wi-Fi 6 devices to mark each frame with a color code that identifies the BSS (Basic Service Set) it belongs to. This helps differentiate between frames from different BSSs that share the same channel and avoid unnecessary collisions and backoffs. BSS coloring also introduces an adaptive threshold for interference, which means that Wi-Fi 6 devices can adjust the signal strength value that determines whether a channel is busy or not based on the current network environment. This allows for more efficient use of spectrum and higher throughput in dense scenarios12.

According to the Aruba Documentation Portal1, the firewall role derivation flow in the correct order is:

• Server derived role
• User derived role
• Authentication default role
• Initiation role assigned