HPE6-A85 Questions and Answers

Aruba’s Captive Portal uses Layer 3 authentication, which means that it intercepts the client’s HTTP requests and redirects them to a web page where the client can enter their credentials. The credentials are then verified by a RADIUS server or a local database before granting network access. References:https://www.arubanetworks.com/techdocs/Instant_86_WebHelp/Content/instant-ug/captive-portal/captive-portal-auth.htm

AAA Authentication, Authorization, and Accounting (AAA) Authentication, Authorization, and Accounting (AAA) is a framework that provides security services for network access control . AAA consists of three components:

• Authentication: The process of verifying the identity of a user or device that wants to access the network based on credentials such as username and password , certificates , tokens , etc . Authentication can use different protocols such as PAP , CHAP , EAP , RADIUS , TACACS+ , etc .
• Authorization: The process of granting or denying access to network resources based on the identity and privileges of a user or device . Authorization can use different methods such as ACLs , RBAC , MAC , DAC , etc .
• Accounting: The process of recording and reporting the activities and usage of network resources by users or devices . Accounting can use different formats such as syslog , SNMP , NetFlow , etc .

service. Here is my answer:

The correct match for each AAA service with its definition is:

• Accounting: C. Tracking user activity on the network
• Authentication: D. Who can access the network based on credentials/certificates
• Authorization: B. Control users access on the network

The other options are not correct matches because:

• A list of rules that specifies which entities are permitted or denied access: This option is a definition of an access control list (ACL) Access Control List (ACL) Access Control List (ACL) is a list of rules that specifies which entities are permitted or denied access to a network resource such as a router , switch , firewall , server , etc . ACLs can be based on different criteria such as source and destination IP addresses , port numbers , protocol types , time of day , etc . ACLs can be applied to different interfaces or directions such as inbound or outbound . ACLs can be verified by using commands such as show access-lists , show ip access-lists , debug ip packet , etc . , not an AAA service.
• Who can access the network based on credentials/certificates: This option is a definition of authentication, not authorization. Authorization is the process of granting or denying access to network resources based on the identity and privileges of a user or device, not based on credentials/certificates.

References: https://en.wikipedia.org/wiki/AAA_(computer_security) https://www.cisco.com/c/en/us/support/docs/security-vpn/remote-authentication-dial-user-service-radius/13838-10.html

The correct statement when comparing 5 GHz and 6 GHz channels with identical channel widths is that 5 GHz channels travel different distances and provide different throughputs to clients compared to 6 GHz channels. This statement reflects the fact that higher frequency signals tend to have higher attenuation Attenuation is a general term that refers to any reduction in signal strength during transmission over distance or through an object or medium . Higher attenuation means that higher frequency signals have shorter range and lower throughput than lower frequency signals. Some facts about this statement are:

• 5 GHz channels have lower frequency than 6 GHz channels, which means they have lower attenuation than 6 GHz channels.
• Lower attenuation means that 5 GHz channels can travel longer distances and provide higher throughputs to clients than 6 GHz channels with identical channel widths.
• However, the difference in distance and throughput between 5 GHz and 6 GHz channels may not be significant in indoor environments where there are many obstacles and reflections that affect signal propagation.
• The advantage of using 6 GHz channels over 5 GHz channels is that they offer more spectrum availability, less interference, and more non-overlapping channels than 5 GHz channels.

The other options are not correct because:

• 5 GHz channels travel the same distances and provide different throughputs to clients compared to 6 GHz channels: This option is false because 5 GHz channels do not travel the same distances as 6 GHz channels due to higher attenuation of higher frequency signals.
• 5 GHz channels travel the same distances and provide the same throughputs to clients compared to 6 GHz channels: This option is false because 5 GHz channels do not travel the same distances or provide the same throughputs as 6 GHz channels due to higher attenuation of higher frequency signals.
• 5 GHz channels travel different distances and provide the same throughputs to clients compared to 6 GHz channels: This option is false because 5 GHz channels do not provide the same throughputs as

6 GHz channels due to higher attenuation of higher frequency signals.

References: https://www.wi-fi.org/discover-wi-fi/wi-fi-certified-6e https://www.wi-fi.org/file/wi-fi-alliance-spectrum-needs-study https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/82068-power-levels.html https://www.cisco.com/c/en/us/products/collateral/wireless/spectrum-expert-wi-fi/prod_white_paper0900aecd807395a9.html

OSPF Open Shortest Path First. OSPF is a link-state routing protocol that uses a hierarchical structure to create a routing topology for IP networks. OSPF routers exchange routing information with their neighbors using Hello packets, which are sent periodically on each interface. To establish an adjacency Adjacency is a relationship formed between selected neighboring routers for the purpose of exchanging routing information., OSPF routers must agree on several parameters, including Hello timers, which specify how often Hello packets are sent on an interface. If the Hello timers do not match between neighboring routers, they will not form an adjacency and will not exchange routes. References:https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/osfp/osfp.htm

Layer: 1) Physical layer Phase of Message Processing: d) Organize the data into bits

Layer: 2) Data Link layer Phase of Message Processing: c) Organize the data into frames

Layer: 3) Network layer Phase of Message Processing: b) Organize the data into packets

Layer: 4) Transport layer Phase of Message Processing: a) Organize the data into segments

The OSI model divides the networking process into seven layers, each representing a different step of the transmission chain. Each layer has its own function and is responsible for well-defined tasks. User data passes sequentially from the highest layer down through the lower layers until the device transmits it externally. The lowest layer, the physical layer, converts the data into bits that can be sent over a physical medium. The second layer, the data link layer, organizes the bits into frames that can be transmitted over a link between two nodes. The third layer, the network layer, organizes the frames into packets that can be routed across a network of nodes. The fourth layer, the transport layer, organizes the packets into segments that can provide reliable and error-free communication between two end points12. References: 1 https://www.linode.com/docs/guides/introduction-to-osi-networking-model/  2 https://en.wikipedia.org/wiki/OSI_model

Only: Daisy chain plus MAD and ring are the recommended VSF topologies for Aruba switches. They provide high availability and redundancy for the VSF stack. MAD (Multiple Active Detection) is a mechanism to detect and resolve split-brain scenarios in a VSF stack. References:https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6790/GUID-D6EF042E-EEEF-49F7-B67E-4CAC41CCB24D.html

The ideal access switch for a large hospital with distribution racks of over 400 ports in a single VSF stack is the CX 6300. This switch provides the following benefits:

• The CX 6300 supports up to 48 ports per switch and up to 10 switches per VSF stack, allowing for a total of 480 ports in a single stack. This meets the requirement of having over 400 ports in a single VSF stack.
• The CX 6300 supports high-performance switching with up to 960 Gbps of switching capacity and up to 714 Mpps of forwarding rate. This meets therequirement of having high throughput and low latency for mobile equipment and patient data.
• The CX 6300 supports advanced features such as dynamic segmentation, policy-based routing, and role-based access control. These features enhance the security and flexibility of the network by applying different policies and roles to different types of devices and users.
• The CX 6300 supports Aruba NetEdit, a network configuration and orchestration tool that simplifies the management and automation of the network. This reduces the complexity and human errors involved in network configuration and maintenance.

The other options are not ideal because:

• OCX 6400: This switch is designed for data center applications and does not support VSF stacking. It also does not support dynamic segmentation or policy-based routing, which are useful for network security and flexibility.
• OCX 6200: This switch is designed for small to medium-sized businesses and does not support VSF stacking. It also has lower switching capacity and forwarding rate than the CX 6300, which may affect the performance of the network.
• OCX 6100: This switch is designed for edge applications and does not support VSF stacking. It also has lower switching capacity and forwarding rate than the CX 6300, which may affect the performance of the network.

References: https://www.arubanetworks.com/assets/ds/DS_CX6300Series.pdf https://www.arubanetworks.com/assets/ds/DS_OC6400Series.pdf https://www.arubanetworks.com/assets/ds/DS_OC6200Series.pdf https://www.arubanetworks.com/assets/ds/DS_OC6100Series.pdf

Aruba AirMatch is a feature that optimizes RF Radio Frequency. RF is any frequency within the electromagnetic spectrum associated with radio wave propagation. When an RF current is supplied to an antenna, an electromagnetic field is created that then is able to propagate through space. performance and user experience by using machine learning algorithms and historical data to dynamically adjust AP power levels, channel assignments, and channel width. AirMatch performs live firmware upgrades on Aruba APs by partitioning all the APs based on RFneighborhood data and minimizing the impact on clients. AirMatch uses a rolling upgrade process that upgrades one partition at a time while ensuring that adjacent partitions are not upgraded simultaneously. References: https://www.arubanetworks.com/assets/ds/DS_AirMatch.pdf https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/arm/AirMatch.htm

Wireless client roaming decisions are made by the client device based on its own criteria, such as signal strength, noise level, data rate, etc. The network can influence the client’s roaming decision by providing information such as neighbor reports, load balancing, band steering, etc., but the final decision is up to the client. References:https://www.arubanetworks.com/techdocs/Instant_86_WebHelp/Content/instant-ug/wlan-roaming/client-roaming.htm

 Virtual Switching Extension (VSX) is a feature that allows two Aruba CX switches to operate as a single logical device with a single control plane and data plane. VSX provides high availability, scalability, and simplified management for campus and data center networks3. In VSX, one switch is designated as the primary switch and the other as the secondary switch. The primary switch owns and responds to ARP Address Resolution Protocol. ARP is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite. requests for the virtual IP address of the VSX pair4. The virtual IP address is used as the default gateway for clients connected to the access switch. If the primary switch fails, the secondary switch takes over the virtual IP address and continues to forward traffic for the clients5. References: 3 https://www.arubanetworks.com/techdocs/AOS-CX_10_04/UG/Content/cx-ug/vsx/vsx-overview.htm  4 https://www.arubanetworks.com/techdocs/AOS-CX_10_04/UG/Content/cx-ug/vsx/vsx-ip-addressing.htm  5 https://www.arubanetworks.com/techdocs/AOS-CX_10_04/UG/Content/cx-ug/vsx/vsx-failover.htm

The status of “ALFOE” means that LACP Link Aggregation Control Protocol (LACP) is a network protocol that provides dynamic negotiation of link aggregation between two devices. LACP allows multiple physical links to be combined into a single logical link for increased bandwidth, redundancy, and load balancing. LACP is defined in IEEE 802.3ad standard. is working fine with no problems when checking LACP with “show lacp interfaces”. The status of “ALFOE” is an acronym that stands for:

• A: Active - The interface is actively sending LACP packets to negotiate link aggregation with the peer device.
• L: Link Up - The interface has physical connectivity with the peer device.
• F: Aggregatable - The interface can be aggregated with other interfaces into a single logical link.
• O: Synchronized - The interface has successfully negotiated link aggregation parameters with the peer device and can transmit or receive traffic on the logical link.
• E: Collecting/Distributing - The interface is collecting incoming traffic from the peer device and distributing outgoing traffic to the peer device on the logical link.

The other options are not correct because:

• The interface on the local switch is configured as static-LAG: This option is false because static-LAG does not use LACP to negotiate link aggregation. Static-LAG requires manual configuration of link aggregation parameters on both devices and does not have any status indicators.
• LACP is not configured on the peer side: This option is false because if LACP is not configured on the peer side, the status of the interface would be “ALF–” instead of “ALFOE”. This means that the interface would not be synchronized or collecting/distributing with the peer device.
• LACP is in a synchronizing process: This option is false because if LACP is in a synchronizing process, the status of the interface would be “ALF-O” instead of “ALFOE”. This means that the interface would not be collecting/distributing with the peer device.

References: https://www.arubanetworks.com/techdocs/AOS-CX_10_08/NOSCG/Content/cx-noscg/lag/lag-overview.htm https://www.arubanetworks.com/techdocs/AOS-CX_10_08/NOSCG/Content/cx-noscg/lag/lag-lacp.htm https://www.arubanetworks.com/techdocs/AOS-CX_10_08/NOSCG/Content/cx-noscg/lag/lag-lacp-status.htm

The main characteristic of the 6 GHz band that is true among the given options is that in North America, the 6 GHz band offers more 80 MHz channels than there are 40 MHz channels in the 5 GHz band. This characteristic provides more spectrum availability, less interference, and higher throughput for wireless devices that support Wi-Fi 6E Wi-Fi Enhanced (Wi-Fi 6E) is an extension of Wi-Fi 6 (802.11ax) standard that operates in the newly available unlicensed frequency spectrum around 6 GHz in addition to existing bands below it. Some facts about this characteristic are:

• In North America, there are up to seven non-overlapping channels available in each of three channel widths (20 MHz, 40 MHz, and 80 MHz) in the entire unlicensed portion of the new spectrum (5925–7125 MHz). This means there are up to 21 non-overlapping channels available for Wi-Fi devices in total.
• In comparison, in North America, there are only nine non-overlapping channels available in each of two channel widths (20 MHz and 40 MHz) in the entire unlicensed portion of the existing spectrum below it (2400–2483 MHz and 5150–5825 MHz). This means there are only up to nine non-overlapping channels available for Wi-Fi devices in total.
• Therefore, in North America, there are more than twice as many non-overlapping channels available in each channel width in the new spectrum than in the existing spectrum below it.
• Specifically, there are more than twice as many non-overlapping channels available at 80 MHz width (seven) than at 40 MHz width (three) in the existing spectrum below it.

The other options are not true because:

• Less RF signal is absorbed by objects in a 6 GHz WLAN: This option is false because higher frequency signals tend to be more absorbed by objects than lower frequency signals due to higher attenuation Attenuation is a general term that refers to any reduction in signal strength during transmission over distance or through an object or medium . Therefore, RF signals in a 6 GHz WLAN would be more absorbed by objects than RF signals in a lower frequency WLAN.
• The 6 GHz band is fully backward compatible with existing bands: This option is false because Wi-Fi devices need to support Wi-Fi 6E standard to operate in the new spectrum around 6 GHz . Existing Wi-Fi devices that do not support Wi-Fi 6Estandard cannot use this spectrum and can only operate in existing bands below it.
• Low Power Devices are allowed for indoor and outdoor usage: This option is false because Low Power Indoor Devices (LPI) are only allowed for indoor usage under certain power limits and registration requirements . Outdoor usage of LPI devices is prohibited by regulatory authorities such as FCC Federal Communications Commission (FCC) is an independent agency of United States government that regulates communications by radio, television, wire, satellite, and cable across United States . However, outdoor usage of Very Low Power Devices (VLP) may be allowed under certain power limits and without registration requirements.

References: https://www.wi-fi.org/discover-wi-fi/wi-fi-certified-6e https://www.wi-fi.org/file/wi-fi-alliance-spectrum-needs-study https://www.cisco.com/c/en/us/products/collateral/wireless/spectrum-expert-wi-fi/prod_white_paper0900aecd807395a9.html https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/82068-power-levels.html https://www.wi-fi.org/file/wi-fi-alliance-unlicensed-spectrum-in-the-us

QoS Quality of Service (QoS) is a set of techniques that manage network resources and provide different levels of service to different types of traffic based on their requirements. QoS can improve network performance, reduce latency, increase throughput, and prevent congestion. concept and its definition. Here is my answer:

QoS Concept:

• Best Effort Service
• Class of Service
• Differentiated Services
• WMM ====================== Definition:

d) A method where traffic is treated equally in a first-come, first-served manner a) A method for classifying network traffic at Layer 2 by marking 802.1Q VLAN Ethernet frames with one of eight service classes b) A method for classifying network traffic at Layer 3 by marking packets with one of 64 different service classes c) A method for classifying network traffic using access categories based on the IEEE 802.11e QoS standard

Short But Comprehensive Explanation of Correct Answer Only: The correct match between QoS concept and its definition is as follows:

• Best Effort Service: This is a method where traffic is treated equally in a first-come, first-served manner without any prioritization or differentiation. This is the default service level for most networks and applications that do not have specific QoS requirements or guarantees. Best Effort Service does not provide any assurance of bandwidth, delay, jitter, or packet loss.
• Class of Service: This is a method for classifying network traffic at Layer 2 by marking 802.1Q VLAN Ethernet frames with one of eight service classes (0 to 7). These service classes are also known as IEEE 802.1p priority values or PCP Priority Code Point (PCP) is a 3-bit field in the 802.1Q VLAN tag that indicates the priority level of an Ethernet frame . Class of Service allows network devices to identify and handle different types of traffic based on their priority levels. Class of Service is typically used in LAN Local Area Network (LAN) is a network that connects devices within a limited geographic area, such as a home, office, or building environments where Layer 2 switching is predominant.
• Differentiated Services: This is a method for classifying network traffic at Layer 3 by marking packets with one of 64 different service classes (0 to 63). These service classes are also known as DiffServ Code Points (DSCP) DiffServ Code Point (DSCP) is a 6-bit field in the IP header that indicates the service class of a packet . Differentiated Services allows network devices to identify and handle different types of traffic based on their service classes. Differentiated Services is typically used in WAN Wide Area Network (WAN) is a network that connects devices across a large geographic area, such as a country or continent environments where Layer 3 routing is predominant.
• WMM: This is a method for classifying network traffic using access categories based on the IEEE 802.11e QoS standard. WMM stands for Wi-Fi Multimedia and it is a certification program developed by the Wi-Fi Alliance to enhance QoS for wireless networks. WMM defines four access categories (AC): Voice, Video, Best Effort, and Background. These access categories correspond to different priority levels and contention parameters for wireless traffic. WMM allows wireless devices to identify and handle different types of traffic based on their access categories.

References: https://en.wikipedia.org/wiki/Quality_of_service https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_dfsrv/configuration/xe-16/qos-dfsrv-xe-16-book/qos-dfsrv-overview.html https://www.cisco.com/c/en/us/support/docs/quality-of-service-qos/qos-packet-marking/10103-dscpvalues.html https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/81831-qos-wlan.html https://www.wi-fi.org/discover-wi-fi/wi-fi-certified-wmm