Free Practice Questions for HP HPE6-A47 Exam

This answer is correct because it follows the best practice design for routing the wireless traffic in a VHD wireless solution. By having the MCs act at Layer2, the architectcan enable the use of clustering, which provides high availability, load balancing, and seamless roaming for wireless users. By having the core routing switches act as the default gateway, the architect can avoid tunneling the wireless traffic to the MCs, which reduces the network overhead and latency. This also allows the core routing switches to apply security policies and QoS to the wireless traffic based on the user roles assigned by the MCs. References:

Aruba Certified Design Professional Official Certification Study Guide (HPE6-A47) - Chapter 6)

Aruba Validated Reference Design: Very High Density 802.11ac Networks - Chapter 4)

Aruba Mobility Controller Clustering - Data sheet)

The architect should recommend the use of Virtual Switching Framework (VSF) in this network because it simplifies the topology and eliminates the need for spanning tree. VSF is a technology that allows multiple Aruba switches to operate as a single logical device, providing high availability, scalability, and simplified management. By using VSF, the architect can reduce the number of links and devices in the network, and avoid the complexity and inefficiency of spanning tree protocol (STP), which is used to prevent loops in a network. VSF also enables faster convergence and recovery in case of link or device failures, as well as load balancing and link aggregation across the switches.

The other options are not valid reasons for using VSF in this network:

Option A is incorrect because VSF does not enable software-defined network monitoring in conjunction with AirWare. AirWare is a network management platform that provides visibility and control over the entire network, including wired and wireless devices, applications, and users. VSF does not directly affect the functionality of AirWare, nor does it provide any additional features for software-defined network monitoring.

Option B is incorrect because VSF does not transform switches into virtual extensions of the MCs to simplify MST management. MCs are mobility controllers that provide centralized control and configuration for wireless access points and gateways. VSF does not integrate the switches with the MCs, nor does it affect the MST (Multiple Spanning Tree) protocol, which is an enhancement of STP that allows multiple instances of STP to run on different VLANs.

Option C is incorrect because VSF does not enable administrators to manage all 18 switches as a single switch. VSF allows the switches to operate as a single logical device, but they still retain their individual identities and configurations. Administrators can use the VSF commander switch as a single point of management for the VSF members, but they still need to access each switch separately for some tasks, such as firmware updates, backups, and restores.

References:

ArubaOS-Switch and ArubaOS-CX Transceiver Guide)

ArubaOS-Switch Management and Configuration Guide for WC.16.10)

ArubaOS-Switch Virtual Switching Framework Configuration Guide for WC.16.10)

The architect should propose one LIC-MM-VA-500 license package for the customer. This license package allows the customer to deploy up to two VMMs and manage up to 500 MCs and 10,000 APs. The customer does not need any additional licenses for the MCs or the APs, as they are included in the LIC-MM-VA-500 package. The other options are either insufficient or excessive for the customer’s needs.

Option A is insufficient because six LIC-MM-VA-50 licenses only allow the customer to manage up to 300 MCs and 6,000 APs. The customer needs to manage 300 APs and six MCs, so this option does not meet the requirement.

Option B is excessive because one LIC-MC-VA-250 and one LIC-MC-VA-50 licenses allow the customer to deploy up to 300 MCs and 6,000 APs, which is more than what the customer needs. Moreover, one LIC-MM-VA-500 license allows the customer to deploy up to two VMMs and manage up to 500 MCs and 10,000 APs, which is also more than what the customer needs. Therefore, this option is wasteful and unnecessary.

Option D is also excessive because one LIC-MC-VA-250 and one LIC-MC-VA-50 licenses allow the customer to deploy up to 300 MCs and 6,000 APs, which is more than whatthe customer needs. Additionally, six LIC-MM-VA-500 licenses allow the customer to deploy up to 12 VMMs and manage up to 3,000 MCs and 60,000 APs, which is way more than what the customer needs. Therefore, this option is also wasteful and unnecessary.

References:

ArubaOS 8.5 Licensing Guide)

Aruba Mobility Master Data Sheet)

Aruba 7000 Series Mobility Controllers Data Sheet)

Aruba Central Managed Portal (MSP) is a cloud-based network management platform that enables service providers to centrally manage and monitor multiple tenant accounts from a single interface1. MSP mode is a multi-tenant operational mode that Aruba Central accounts can be converted into, provided these accounts have subscribed to the Aruba Central app2. MSP mode allows service providers to provision and manage tenant accounts, assign devices to tenant accounts, manage subscription keys and perform other functions such as configuring network profiles and viewing alerts3. MSP mode is suitable for the scenario where a service provider needs to manage multiple customer networks, as it simplifies tenant network operations using capabilities such as zero-touch setup, historical data reporting, PCI compliance monitoring, and troubleshooting2. References:

1: MSP Overview - Aruba

2: MSP Architecture - Aruba

3: Managed Service Portal - Aruba

A wide sector directional antenna is a type of antenna that radiates or receives radio waves in a sector-shaped pattern, covering a wide angle of a circle. The width of the sector is determined by the horizontal beamwidth (H-plane) of the antenna, while the height of the sector is determined by the vertical beamwidth (E-plane) of the antenna12. A wide sector directional antenna is usually used to provide regional coverage for wireless networks, such as Wireless Internet Service Providers (WISP) or similar applications2.

According to the antenna specifications given, Antenna 3 has the widest horizontal beamwidth of 100 degrees, which means it can cover a large sector of a circle. Antenna 4 has a narrower horizontal beamwidth of 60 degrees, which means it can cover a smaller sector of a circle. Antenna 1 and Antenna 2 have a horizontal beamwidth of 360 degrees, which means they are omnidirectional antennas, not directional antennas. Therefore, Antenna 3 is the best choice for the plan that specifies wide sector directional antennas.

References:

1: https://en.wikipedia.org/wiki/Sector_antenna

2: https://lcantennas.com/directional-antennas/

 Aruba AirWare is a network management solution that provides real time statistics and assessment of call quality for Skype for Business UC solution. It integrates with Skype for Business SDN API to monitor and troubleshoot voice and video calls, and optimize network performance and user experience. It also provides visibility into network health, application performance, and user behavior across wired and wireless networks. Aruba Central is a cloud-based network management solution that does not support Skype for Business integration. Aruba Mobility Master (MM) is a network controller that manages Aruba access points and switches, but does not provide call quality statistics or assessment. Aruba ClearPass is a network access control solution that provides secure authentication and policy enforcement, but does not monitor or optimize Skype for Business calls. References: Aruba AirWave Network Management), Aruba AirWave and Microsoft Skype for Business Integration Guide)

 A collision domain is a logical area of the network where devices share the same wireless medium and may interfere with each other’s transmissions. In a WLAN, a collision domain is defined by the channel and the coverage area of an AP or a client. Devices that operate on the same channel and are within range of each other belong to the same collision domain and must contend for access to the medium using the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. Devices that operate on different channels or are out of range of each other belong to different collision domains and do not interfere with each other.

In this scenario, the architect plans 12 APs for an auditorium that is 325 square meters (3,498 square feet). Each AP has one 2.4 GHz radio and one 5 GHz radio. Both types of radios use 20 MHz channels. Assuming that DFS channels can be used in this design, the question is how many 5 GHz collision domains does this design provide.

To answer this question, we need to consider the following factors:

The number of available 5 GHz channels in the regulatory domain of the auditorium. Different countries have different regulations on the use of the 5 GHz band, which affects the number and availability of channels for WLANs. For example, in the United States, there are 25 non-overlapping 20 MHz channels in the 5 GHz band, but some of them are subject to Dynamic Frequency Selection (DFS) requirements, which means that they must avoid interfering with radar systems by detecting and switching to another channel if radar signals are present. In other countries, such as Japan, there are 19 non-overlapping 20 MHz channels in the 5 GHz band, but some of them are restricted to indoor use only. Therefore, the number of available 5 GHz channels for the design depends on the regulatory domain of the auditorium.

The channel assignment and distribution of the 12 APs in the auditorium. The channel assignment and distribution of the APs affect the number and size of the collision domains in the WLAN. Ideally, the APs should be assigned to non-overlapping channels and distributed evenly across the auditorium to provide optimal coverage and capacity, while minimizing co-channelinterference and adjacent channel interference. Co-channel interference occurs when devices on the same channel interfere with each other, while adjacent channel interference occurs when devices on nearby channels interfere with each other. Both types of interference degrade the performance and quality of the WLAN. Therefore, the channel assignment and distribution of the APs should follow the best practices of RF design, such as using a channel reuse plan, avoiding channel overlap, and adjusting the transmit power and antenna gain of the APs to match the coverage and capacity requirements of the auditorium.

The coverage and capacity requirements of the auditorium. The coverage and capacity requirements of the auditorium affect the number and placement of the APs and the transmit power and antenna gain settings of the radios. The coverage requirement refers to the minimum signal strength and signal-to-noise ratio (SNR) that the APs and clients need to maintain a reliable wireless connection. The capacity requirement refers to the maximum number of clients and the minimum throughput and quality of service (QoS) that the APs and clients need to support the applications and services of the auditorium. The coverage and capacity requirements of the auditorium depend on the size and shape of the space, the density and distribution of the clients, the types and characteristics of the applications and services, and the performance and capabilities of the devices. Therefore, the coverage and capacity requirements of the auditorium should be determined by conducting a site survey and a network analysis, and then used to guide the design and configuration of the APs and radios.

Based on these factors, we can estimate the number of 5 GHz collision domains in the design as follows:

Assuming that the auditorium is located in the United States and that DFS channels can be used in the design, there are 25 non-overlapping 20 MHz channels in the 5 GHz band. However, not all of them may be available or suitable for the design, depending on the presence and activity of radar systems in the area, the compatibility and support of the APs and clients, and the interference and noise level of the environment. Therefore, we will use a conservative estimate of 15 available 20 MHz channels in the 5 GHz band for the design.

Assuming that the 12 APs are assigned to non-overlapping channels and distributed evenly across the auditorium, each AP will have its own 5 GHz collision domain, as there will be no co-channel interference or adjacent channel interference among the APs. Therefore, there will be 12 5 GHz collision domains in the design, corresponding to the 12 APs.

Assuming that the coverage and capacity requirements of the auditorium are moderate and that the transmit power and antenna gain settings of the radios are adjusted accordingly, each AP will cover an area of about 27 square meters (290 square feet), which is roughly the size of a small classroom. This means that the APs will provide adequate signal strength and SNR for the clients, while avoiding excessive overlap and interference among the APs. Therefore, there will be no need to further divide or merge the 5 GHz collision domains in the design, as they will match the coverage and capacity requirements of the auditorium.

Hence, the number of 5 GHz collision domains in the design is 12, which is the answer option C. References:

RF Design | Validated Solution Guide - Aruba

Configuring 2.4 Ghz and 5 Ghz Radios - Aruba

Chapter T-5: Understanding RF Collision Domains - Aruba

[Aruba Certified Design Professional Official Certification Study Guide (HPE6-A47)]

 A metal firewall is a significant RF obstacle that can be difficult to see visually and might require access to blueprints. A metal firewall is a type of fire-resistant barrier that is made of metal or metal-clad materials and is used to separate different sections of a building or a network. A metal firewall can block or attenuate RF signals that pass through it, causing coverage gaps, signal degradation, or interference in the wireless deployment. A metal firewall can also reflect RF signals, creating multipath fading or distortion in the wireless environment. Therefore, an architect needs to identify the location and thickness of any metal firewalls in the building and account for their impact on the RF design. A metal firewall may require additional access points, antennas, or cabling to provide adequate coverage and performance across the wireless deployment. A metal firewall may also affect the channel planning, transmit power settings, and antenna orientation of the access points and radios. A metal firewall can be difficult to see visually, as it may be hidden behind walls, ceilings, or floors, or blended with other materials.Therefore, an architect might need access to blueprints or other sources of information to locate and measure any metal firewalls in the building. References:

RF Design | Validated Solution Guide - Aruba

Managing and Optimizing RF Spectrum for Aruba WLANs | PDF - SlideShare

RF Optimization - Aruba

Advanced RF Design & Troubleshooting | PPT - SlideShare

For a VHD wireless network at a large events venue, the architect should ensure that the DHCP and DNS servers are carrier-grade and support a low transaction time. This is because the DHCP and DNS servers are responsible for providing IP addresses and name resolution for the wireless devices, and they need to handle a high volume of requests and responses in a short time. A low transaction time reduces the latency and improves the user experience. A carrier-grade server is a server that meets the high standards of reliability, availability, and scalability required by telecom operators and service providers. A carrier-grade server can handle a large number of concurrent connections, provide redundancy and fault tolerance, and offer high performance and security.

Option A is incorrect because the DHCP server can support a high number of scopes with a /24 size, but this does not guarantee a low transaction time or a carrier-grade service. A scope is a range of IP addresses that the DHCP server can assign to the clients. A /24 size means that each scope can have up to 254 hosts. However, the number of scopes does not affect the speed or quality of the DHCP service. Option B is incorrect because a third-party firewall integrates with ClearPass to filter the guest user traffic, but this does not affect the DHCP and DNS services. A firewall is a device that monitors and controls the network traffic based on predefined rules. ClearPass is a network access control solution that provides secure authentication and policy enforcement. A firewall integration with ClearPass can enhance the security and visibility of the guest user traffic, but it does not improve the performance or reliability of the DHCP and DNS servers. Option C is incorrect because a domain CA is set up to deploy certificates to a high volume of guest devices, but this does not affect the DHCP and DNS services. A certificate authority (CA) is an entity that issues digital certificates that verify the identity and authenticity of the devices. A domain CA is a CA that is part of a domain and can issue certificates to the domain members. A certificate deployment is a process of distributing and installing the certificates to the devices. A certificate deployment can improve the security and trust of the wireless network, but it does not improve the speed or quality of the DHCP and DNS servers. References: Aruba Validated Design: Very High Density 802.11ac Networks), Aruba Validated Design: Campus Wired LAN), Aruba Validated Design: Guest Access)