HPE7-A01 Sample Questions 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

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

This is the correct statement about what happens when a client attempts to join the network and the WLAN is configured with OWE (Opportunistic Wireless Encryption). OWE is a standard that provides encryption for open networks without requiring any authentication or credentials from the client or the network. OWE uses a Diffie-Hellman key exchange mechanism to establish a secure session between the client and the AP without exchanging any authentication information. The other options are incorrect because they either describe scenarios that require authentication or encryption methods that are not used by OWE. References: https://www.arubanetworks.com/assets/wp/WP_WiFi6.pdf https://www.arubanetworks.com/assets/ds/DS_AP510Series.pdf

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.

• Proves knowledge of the PMK
• Exchanges messages for generating PTK
• Distributes an encrypted GTK to the client
• Sets first initialization vector (IV)

The other options either use more commands or do not create the VRF or the VLAN.

Option C uses the following commands:

• vrf eng: This command creates a VRF named eng and enters the VRF configuration mode1.
• vlan 25: This command creates a VLAN with ID 25 and enters the VLAN configuration mode2.
• interface vlan 25: This command creates an SVI on VLAN 25 and enters the interface configuration mode3.
• ip address 10.105.43.1/24 ipv6 address fd00:5780::102d:4df6/64 vrf attach eng: This command assigns an IPv4 address of 10.105.43.1 with a subnet mask of 255.255.255.0 and an IPv6 address of fd00:5780::102d:4df6 with a prefix length of 64 to the SVI, and attaches it to the VRF eng.

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

AOS 10 Gateways can have the following personas: Mobility, Branch, and VPN Concentrator1 However, the Mobility persona is only available when configuring a Gateway-only group, which is a group that contains only one gateway device2 The Mobility persona provides Overlay WLAN and (or) wired LAN functionalities for campus networks1 The Branch persona provides the Aruba Instant OS and SD-Branch (LAN + WAN) functionality for branch and microbranch networks1 The VPN Concentrator persona provides VPN termination and routing functionality for remote access networks3 The Edge persona is not a valid option, as it is not a supported device persona for AOS 10 Gateways.

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

BSS coloring is a mechanism that helps identify the BSS Basic Service Set. A BSS is a set of interconnected stations that can communicate with each other. BSS can be an independent BSS or infrastructure BSS. An independent BSS is an ad hoc network that does not include APs, whereas the infrastructure BSS consists of an AP and all its associated clients. on the same channel and differentiate them from other BSS on the same channel12. Each BSS is assigned a color code, which is a 6-bit value that is carried in the PHY header of the Wi-Fi frames12. By using BSS coloring, the APs and clients can reduce the threshold for interference detection and avoid unnecessary backoff or retransmissions when they detect frames from other BSS with different colors12. This can improve the spectral efficiency and throughput of the network12. The other options are incorrect because they do not describe the primary benefit of BSS coloring.

The reason is that PBR allows you to route packets based on policies that match certain criteria, such as source or destination IP addresses, ports, protocols, etc. PBR can also be used to set metrics, next-hop addresses, or tag traffic for different routes.

The default value for config-revision on Core-1 is 0. Config-revision is a parameter that indicates the configuration version of a VSX pair. It is used to synchronize the configuration between the VSX peers and to detect any configuration mismatch. The config-revision value is set to 0 by default on both VSX peers and is incremented by 1 every time a configuration change is made on either peer. The other options are incorrect because they do not reflect the default value of config-revision. 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

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

EVPN-VXLAN is a technology that allows layer-2 communication across layer-3 networks by using Ethernet VPN (EVPN) as a control plane and Virtual Extensible LAN (VXLAN) as a data plane3. EVPN-VXLAN can be used to support legacy applications that communicate at layer-2 across different campuses or data centers that are connected via layer-3. EVPN-VXLAN minimizes flooding by using BGP to distribute MAC addresses and IP addresses of hosts across different VXLAN segments3. EVPN-VXLAN also provides benefits such as loop prevention, load balancing, mobility, and scalability3. References: 3 https://www.arubanetworks.com/assets/tg/TG_EVPN_VXLAN.pdf

According to the Aruba Documentation Portal1, 802.1X is a standard for port-based network access control that uses a RADIUS server to authenticate and authorize wireless clients. 802.1X can be configured in different modes, such as bridge mode, tunnel mode, or split tunnel mode.

Option C: GRE tunnel

This is because option C shows how to configure an SSID in tunnel mode with the default AP-group settings on an Aruba switch. In tunnel mode, all client traffic from the access points is tunneled back to the controller and the controller would in turn put the client traffic onto the network2. The GRE protocol is used to encapsulate and decapsulate the traffic between the access points and the controller3.

Therefore, option C is correct.

1: https://www.arubanetworks.com/techdocs/AOS-CX/10.06/HTML/5200-7696/GUID-581D2976-694B-46C7-8497-F6B788AA05B2.html  2: https://community.arubanetworks.com/discussion/bridge-and-tunnel-mode  3: https://www.twingate.com/blog/ipsec-tunnel-mode

The show aaa authentication port-access interface all client-status command displays the status of all clients authenticated by port-based access control on all interfaces. The output includes the MAC address, user role, VLAN ID, and session timeout for each client. This command can be used to examine information on which role the guest user has been assigned by the AOS-CX switch. References: https://techhub.hpe.com/eginfolib/Aruba/OS-CX_10.04/5200-6692/GUID-9B8F6E8F-9C7A-4F0D-AE7B-9D8E6C5B6A7F.html

Spectrum Monitor is an Aruba AP mode that is sending captured RF data to Aruba Central for waterfall plot. Spectrum Monitor is a mode that allows an AP to scan all channels in both 2.4 GHz and 5 GHz bands and collect information about the RF environment, such as interference sources, noise floor, channel utilization, etc. The AP then sends this data to Aruba Central, which is a cloud-based network management platform that can display the data in various formats, including waterfall plot. Waterfall plot is a graphical representation of the RF spectrum over time, showing the frequency, amplitude, and duration of RF signals. The other options are incorrect because they are either not AP modes or not sending RF data to Aruba Central. References: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/1-overview/spectrum_monitor.htm https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/1-overview/waterfall_plot.htm https://www.arubanetworks.com/products/network-management-operations/aruba-central/

• Client IP address: This factor can be used to determine if the client is on the same VLAN as the AP or not. If the client IP address is on the same VLAN as the AP, then the client traffic is bridged locally. If the client IP address is on a different VLAN than the AP, then the client traffic is forwarded to the gateway cluster through a secure tunnel 12.
• Client VLAN: This factor can be used to determine if the client belongs to a specific VLAN or not. If the client belongs to a specific VLAN, then the client traffic is forwarded to that VLAN based on its IP address and security profile 12.

This is because Best Effort traffic is all other kinds of non-detrimental traffic that are not sensitive to Quality of Service metrics (jitter, packet loss, latency). A typical example would be peer-to-peer and email applications2. Background traffic is a type of traffic that is used for system maintenance or backup purposes and does not affect the performance or availability of the network3.

Therefore, Best Effort traffic has a higher priority than Background traffic in terms of network resources allocation and management.

1: https://www.arubanetworks.com/techdocs/ArubaDocPortal/content/docportal.htm  2: https://stackoverflow.com/questions/33854306/best-effort-traffic-and-real-time-traffic-difference  3: https://www.informit.com/articles/article.aspx?p=25315 &seqNum=4

The correct steps that are part of the Key Management workflow when a wireless device is roaming from AP1 to AP2 are A and D.

A. AP1 will cache the client’s information and send it to the Key Management service. This is true because when a client associates and authenticates with AP1, AP1 will generate a pairwise master key (PMK) for the client and store it in its cache. AP1 will also send the PMK and other client information, such as MAC address, VLAN, and SSID, to the Key Management service, which is a centralized service that runs on Aruba Mobility Controllers (MCs) or Mobility Master (MM) devices1. The Key Management service will use this information to facilitate fast roaming for the client.

D. The Key Management service then generates R1 keys for AP2’s neighbors. This is true because when the Key Management service receives the client information from AP1, it will use the PMK to derive R0 and R1 keys for the client. R0 keys are used to generate R1 keys, which are used to generate pairwise transient keys (PTKs) for encryption. The Key Management service will distribute the R1 keys to AP2 and its neighboring APs, which are determined by AirMatch based on RF proximity2. This way, when the client roams to AP2 or any of its neighbors, it can skip the 802.1X authentication and use the R1 key to quickly generate a PTK with the new AP3.

B. The Key Management service receives from AirMatch a list of all AP2’s neighbors. This is false because the Key Management service does not receive this information from AirMatch directly. AirMatch is a feature that runs on MCs or MM devices and optimizes the RF performance of Aruba devices by using machine learning algorithms. AirMatch periodically sends neighbor reports to all APs, which contain information about their nearby APs based on signal strength and interference. The APs then send these reports to the Key Management service, which uses them to determine which APs should receive R1 keys for a given client2.

C. The Key Management service receives a list of all AP1 s neighbors from AirMatch. This is false for the same reason as B. The Key Management service does not receive this information from AirMatch directly, but from the APs that send their neighbor reports.

E. A client associates and authenticates with the AP2 after roaming from AP1. This is false because a client does not need to authenticate with AP2 after roaming from AP1 if it has already authenticated with AP1 and received R1 keys from the Key Management service. The client only needs to associate with AP2 and perform a four-way handshake using the R1 key to generate a PTK for encryption3. This is called fast roaming or 802.11r roaming, and it reduces the latency and disruption caused by full authentication.

1: ArubaOS 8.7 User Guide 2: ArubaOS 8.7 User Guide 3: ArubaOS 8.7 User Guide : ArubaOS 8.7 User Guide

The correct action to fix the issue is C. Change the SSID to WPA3-Enhanced Open.

WPA3-OWE is not a valid SSID type in Central. OWE stands for Opportunistic Wireless Encryption, and it is a feature that provides encryption for open networks without requiring authentication. OWE is also known as Enhanced Open, and it is one of the options for WPA3 SSIDs in Central1.

According to the Aruba document Configuring WLAN Settings for an SSID Profile, one of the steps to configure a WPA3 SSID is:

• Select the Security Level from the drop-down list. The following options are available:

The other options are incorrect because:

• A. WPA3-Enterprise (CNSA) is a valid SSID type, but it requires 802.1X authentication with a RADIUS server, which may not be suitable for the company’s use case.
• B. WPA3-Personal is a valid SSID type, but it requires a passphrase to join the network, which may not be suitable for the company’s use case.
• D. WPA3-Enterprise (CCM) is a valid SSID type, but it requires 802.1X authentication with a RADIUS server, which may not be suitable for the company’s use case.

The Aruba CX 6400 switch is a modular switch that supports high-performance and high-density Ethernet switching for campus and data center networks. One of the features that distinguishes the Aruba CX 6400 switch from most typical campus switches is virtual output queueing (VOQ). VOQ is a technique that implements large ingress packet buffers on each port to prevent head-of-line blocking and packet loss due to congestion2. VOQ allows each port to have multiple queues for different output ports and prioritize packets based on their destination and QoS class2. VOQ enables the Aruba CX 6400 switch to achieve high throughput and low latency for various traffic types and scenarios. References: 2 https://www.arubanetworks.com/assets/ds/DS_CX6400Series.pdf

The correct answer is C. sysops.

The sysops user role is a predefined role that allows users to view switch configuration information and have access to the PUT and POST methods for REST API. The sysops user role can also use the PATCH and DELETE methods for REST API, but not for all resources. The sysops user role is suitable for users who need to perform system operations on the switch, such as backup, restore, upgrade, or reboot.

According to the AOS-CX REST API Reference basics1, one of the predefined user roles is:

• sysops: Users with this role can view switch configuration information and have access to the PUT and POST methods for REST API. They can also use the PATCH and DELETE methods for REST API, but not for all resources. Users with this role can perform system operations on the switch, such as backup, restore, upgrade, or reboot.

The other options are incorrect because:

• A. administrators: Users with this role have full access to all switch configuration information and all REST API methods. This role is more than what the customer requires.
• B. auditors: Users with this role can only view switch configuration information and have access to the GET method for REST API. They cannot use the PUT and POST methods for REST API.
• D. helpdesk: Users with this role can view switch configuration information and have access to the GET method for REST API. They can also use the PATCH method for REST API, but only for a limited set of resources. They cannot use the PUT and POST methods for REST API.

a) A device with IP address 10.1.3.7 in a network wants to send the traffic stream to a device with IP address 10.13.4.2 in the other network -> Unicast 

b) One/more senders and one/more recipients participate in data transfer traffic -> Multicast 

c) Sent to all hosts on a remote network -> IP Directed Broadcast 

d) Sent to all NICs on the same network segment as the source NIC -> Broadcast

References: 1 https://www.thestudygenius.com/unicast-broadcast-multicast/

The terms broadcast, IP directed broadcast, multicast, and unicast are different types of communication or data transmission over a network. They differ in how many devices are involved in the communication and how they address the messages. The following table summarizes the characteristics of each term1:

A screenshot of a computer Description automatically generated with medium confidence

According to the Aruba Documentation Portal1, user-based tunneling (UBT) is a feature that uses GRE to tunnel ingress traffic on a switch interface to a gateway for further processing. UBT enables a switch to provide a centralized security policy, using per-user authentication and access control to ensure consistent access and permissions.

Option A: The switch will put the client on the access VLAN

This is because option A shows how UBT works on an Aruba switch. When a device connects to the network, it is authenticated using either MAC Authentication or 802.1X and triggers an enforcement policy from ClearPass, which contains an enforcement profile with a user role configuration. The user role can be assigned locally on the switch or on ClearPass as part of an enforcement profile. The user role determines the VLAN that the device belongs to and the access policies that apply to it23.

Therefore, option A is correct.

1: https://www.arubanetworks.com/techdocs/central/latest/content/nms/aos-cx/cfg/conf-cx-ubt.htm  2: https://www.arubanetworks.com/techdocs/AOS-CX/10.06/HTML/5200-7696/GUID-581D2976-694B-46C7-8497-F6B788AA05B2.html  3: https://community.arubanetworks.com/viewdocument/?DocumentKey=c740df4e-3e26-4cc5-9126-355a18709c44 &CommunityKey=2fd943a6-8898-4dbe-915f-4f09e4d3c317&tab=librarydocuments

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

The correct answers are A and D.

According to the web search results, VSX LAG 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. VSX LAGs span both aggregation switches and appear as one device to partner downstream or upstream devices or both when forming a LAG with the VSX pair2.

One of the statements that is true about VSX LAG is that the total number of configured links may not exceed 8 for the pair or 4 per switch1. This means that a VSX LAG across a downstream switch can have at most a total of eight member links, and a switch can have a maximum of four member links. When creating a VSX LAG, it is recommended to select an equal number of member links in each segment for load balancing1.

Another statement that is true about VSX LAG is that outgoing traffic is preferentially switched to local members of the LAG2. This means that when active forwarding and active gateway are enabled, north-south and south-north traffic bypasses the ISL link and uses the local ports on the switch. This optimizes the traffic path and reduces the load on the ISL link2.

The other statements are false or not relevant for VSX LAG. Outgoing traffic is not switched to a port based on a hashing algorithm, which may be either switch in the pair. This is a characteristic of MLAG (Multi-Chassis Link Aggregation), which is a different feature from VSX LAG. LAG traffic is not passed over VSX ISL links only while upgrading firmware on the switch pair. This is a scenario that may occur when performing hitless upgrades, which is a feature that allows software updates without impacting network availability. The number of VSX lags that can be configured on all 83xx and 84xx model switches is not 255, but depends on the switch model and firmware version. For example, the AOS-CX 10.04 supports up to 64 VSX lags for 8320 switches and up to 128 VSX lags for 8325 and 8400 switches.

The command loop-protect enables loop protection on each layer 2 interface (port, LAG, or VLAN) for which loop protection is needed. Loop protection can find loops in untagged layer 2 links, as well as on tagged VLANs.

This is the most likely cause of the issue where the access points in a Microbranch group are online in Aruba Central, but no VPN tunnels are forming. A Microbranch group is a group that contains both APs and Gateways and allows them to form VPN tunnels for secure communication. The VPN tunnels use GRE (Generic Routing Encapsulation) as the encapsulation protocol and IPSec as the encryption protocol. If there is a firewall blocking GRE traffic between the AP and the gateway, the VPN tunnels cannot be established. The other options are incorrect because they either do not affect the VPN tunnel formation or do not apply to a Microbranch group. References: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/gateways/microbranch.htm https://www.arubanetworks.com/assets/tg/TB_ArubaGateway.pdf

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

Option C is the only action that configures the DHCP relay on the SVI of VLAN 1000 on the CX 8360 switches. DHCP relay is a feature that allows a switch to forward DHCP requests from clients in one subnet to a DHCP server in another subnet. DHCP relay is required when the DHCP server and the clients are not in the same broadcast domain1.

Option C uses the following commands:

• interface vlan 1000: This command enters the interface configuration mode for the SVI of VLAN 1000, which has an IP address of 10.102.39.1/24 and is used for wireless clients.
• ip helper-address vrf default 10.200.1.100: This command configures the IP address of the DHCP server as a helper address for the SVI, which means that the switch will forward DHCP requests from clients on VLAN 1000 to this address. The vrf default parameter indicates that the SVI and the DHCP server are in the same VRF.