HPE3-U01 Practice Exam Questions with Answers Aruba Certified Network Technician Exam (ACNT) Certification

A BSSID is a 48-bit label that identifies a basic service set (BSS) within a wireless network. A BSS is a subgroup of devices that share physical-layer medium access characteristics, such as radio frequency, modulation scheme, and security settings. A BSSID is usually the MAC address of the access point (AP) that creates the BSS, or a randomly generated value in an ad hoc network. A BSSID is different from an SSID, which is the name of the wireless network that users see and connect to. An SSID can have multiple BSSIDs associated with it, depending on the number and location of the APs. A BSSID is used to differentiate between different BSSs and to facilitate roaming and load balancing among them. References: https://internetspeedtest.world/wiki/bssid

https://www.minthaik.com/bssid-basic-service-set-identifier/

 A Wi-Fi frame is a unit of data transmission in a wireless network that follows the 802.11 standard. There are three types of Wi-Fi frames: management, control, and data. Management frames are used to establish and maintain the connection between wireless devices, such as access points (APs) and stations (STAs). Control frames are used to coordinate the access to the wireless medium and avoid collisions. Data frames are used to carry the actual information between wireless devices1

A Service Set Identifier (SSID) is a name that identifies a wireless network. A Basic Service Set Identifier (BSSID) is a unique identifier for a wireless access point within a wireless network. A BSSID is usually the MAC address of the wireless interface of the AP. An SSID can be associated with multiple BSSIDs, forming an Extended Service Set (ESS). For example, a wireless network with multiple APs can have the same SSID but different BSSIDs for each AP23

A beacon is a type of management frame that is periodically broadcasted by an AP to announce its presence and provide information about the wireless network, such as the SSID, the BSSID, the supported data rates, the security parameters, and the channel number. A beacon is used by STAs to discover and join a wireless network, as well as to synchronize their clocks with the AP. A beacon is usually sent every 100 milliseconds on a fixed interval45

Therefore, the Wi-Fi frame that announces the SSID to BSSID mapping is the beacon, as it contains both the SSID and the BSSID fields in its frame format. The other options are not correct because:

• An association request is a type of management frame that is sent by a STA to an AP to request to join a wireless network. It contains the SSID of the network that the STA wants to join, but not the BSSID of the AP. The BSSID is specified in the association response frame that is sent by the AP to the STA to accept or reject the request4
• A probe request is a type of management frame that is sent by a STA to scan for available wireless networks. It can contain the SSID of a specific network that the STA wants to join, or it can be blank to request information from all networks. It does not contain the BSSID of any AP. The BSSID is specified in the probe response frame that is sent by the AP to the STA to provide information about the network4
• A network allocation vector (NAV) is not a type of Wi-Fi frame, but a mechanism to avoid collisions in a wireless network. It is a timer that indicates how long the wireless medium will be busy for a transmission. Each Wi-Fi frame contains a duration field that specifies the NAV value for that transmission. The NAV value is updated by the wireless devices based on the duration field of the received frames. A wireless device will not transmit any frame if the NAV value is greater than zero, meaning that the medium is occupied.

References: 1: Wi-Fi Frames: A Brief Intro - Cisco Blogs 2: SSID vs BSSID: What’s the Difference? - Actiontec.com 3: Difference Between BSSID and SSID | Difference Between 4: 802.11Management Frames - Tutorialspoint 5: [Beacon frame - Wikipedia] : [Association Request frame - 802.11 Wireless Networks: The Definitive Guide, 2nd Edition [Book]] : [Probe Request frame - 802.11 Wireless Networks: The Definitive Guide, 2nd Edition [Book]] : [Network Allocation Vector - an overview | ScienceDirect Topics] : [NAV (Network Allocation Vector) - GeeksforGeeks]

The management plane is the logical path of all traffic related to the management of the device. Examples of protocols processed in the management plane are Simple Network Management Protocol (SNMP), Telnet, HTTP, Secure HTTP (HTTPS), and SSH. These management protocols are used for monitoring and for command-line interface (CLI) access12. Therefore, HTTPS and SSH are protocols that operate on the management plane, while the other options are not. TCP is a transport layer protocol that provides reliable data delivery for various applications, but it is not specific to the management plane3. ARP is a network layer protocol that resolves IP addresses to MAC addresses, but it is not used for device management4. STP is a data link layer protocol that prevents loops in switched networks, but it is not related to the management plane5. References: 1: Management Plane Protection - Cisco 2: Planes of Operation > IP Routing on Cisco IOS, IOS XE, and IOS XR: How … 3: [Transmission Control Protocol - Wikipedia] 4: [Address Resolution Protocol - Wikipedia] 5: [Spanning Tree Protocol - Wikipedia] : https://en.wikipedia.org/wiki/Transmission_Control_Protocol : https://en.wikipedia.org/wiki/Address_Resolution_Protocol : https://en.wikipedia.org/wiki/Spanning_Tree_Protocol

To enable internet access on a multilayer switch, you need to configure a default route that points to the ISP router as the next hop. A default route is a special type of static route that matches any destination IP address that is not found in the routing table. The syntax for adefault route is ip route 0.0.0.0 0.0.0.0 , where 0.0.0.0 0.0.0.0 means any IP address and any subnet mask. Alternatively, you can use the slash notation 0.0.0.0/0 to represent the same thing. Therefore, the correct configuration line to enter on the switch is ip route 0.0.0.0/0 172.16.31.254, which means that any traffic that is not destined for a local network will be forwarded to the ISP router at 172.16.31.254.

The other options are incorrect because they either use the wrong syntax or the wrong IP address. Option A uses the route command instead of the ip route command, which is not valid on a multilayer switch. Option C uses the routing command instead of the ip route command, which is also not valid on a multilayer switch. Option D uses the ip routing command instead of the ip route command, which is used to enable routing on the switch, not to configure a default route. Option D also omits the dots in the IP address and the subnet mask, which makes it invalid.

References:

• What Is a Multilayer Switch and How to Use It?
• Inter-VLAN Routing Configuration - 2024 Step-by-Step Tutorial
• Multilayer Switch - Configuring IP Multilayer Switching

According to the Ethernet cable standards, Cat 6 UTP-based cabling can support 1 Gbps data rates up to 100 meters (328 feet) of cable length. This is the maximum recommended distance for a single cable run between a host and the switch where it is plugged in. If the cable length exceeds 100 meters, the signal quality may degrade and cause errors or lower performance. Cat 6 UTP-based cabling can also support 10 Gbps data rates up to 37-55 meters (121-180 feet), depending on the alien crosstalk atmosphere. However, for 10 Gbps data rates, Cat 6a UTP-based cabling is preferred, as it can support the full 100 meters of cable length. References https://networkengineering.stackexchange.com/questions/81114/degradation-of-signal-quality-as-a-function-of-cat-6-cable-length

https://www.howtogeek.com/813419/how-long-can-an-ethernet-cable-be/

To save the switch configuration changes, so they survive a switch reboot, you can use either the write memory or the save memory command. Both commands perform the same function, which is to copy the running configuration to the startup configuration. The running configuration is the current active configuration in the switch’s RAM, while the startup configuration is the configuration that is loaded when the switch boots up. By saving the configuration changes to the startup configuration, you ensure that they are preserved after a reboot12. The other commands are not valid for saving the configuration changes. The copy running-config checkpoint backup and copy running-config checkpoint startup-config commands are used to create checkpoints, which are snapshots of the running configuration that can be used to roll back changes in case of errors3. The store memory command does not exist in Aruba switches. References: 1: Saving Configuration Changes - Aruba 2: [ArubaOS-Switch 16.10 CLI Reference Guide] 3: [ArubaOS-Switch 16.10 Configuration and Management Guide] : https://www.arubanetworks.com/techdocs/ArubaOS-Switch_16.10/5200-6928.pdf : https://www.arubanetworks.com/techdocs/ArubaOS-Switch_16.10/5200-6929.pdf

 The header in the exhibit belongs to the Internet Protocol version 4 (IPv4), which is the most widely used protocol for routing and delivering packets across networks. IPv4 is a connectionless and unreliable protocol that operates at the network layer of the OSI model. The IPv4 header consists of 20 bytes (160 bits) of fixed fields and up to 40 bytes (320 bits) of optional fields. The fixed fields include:

• Version: 4 bits that indicate the version of the IP protocol, which is 4 for IPv4.
• IHL (Internet Header Length): 4 bits that indicate the length of the IP header in 32-bit words, which is 5 for the minimum header size of 20 bytes.
• Type of Service: 8 bits that indicate the quality of service (QoS) parameters for the packet, such as precedence, delay, throughput, and reliability.
• Total Length: 16 bits that indicate the total length of the IP packet in bytes, including the header and the data.The maximum value is 65535 bytes.
• Identification: 16 bits that identify the packet for fragmentation and reassembly purposes.
• Flags: 3 bits that control the fragmentation of the packet. The first bit is reserved and must be zero. The second bit is the Don’t Fragment (DF) bit, which indicates whether the packet can be fragmented or not. The third bit is the More Fragments (MF) bit, which indicates whether the packet is the last fragment or not.
• Fragment Offset: 13 bits that indicate the position of the fragment in the original packet, measured in units of 8 bytes.
• TTL (Time To Live): 8 bits that indicate the maximum number of hops that the packet can traverse before being discarded. The TTL is decremented by one at each hop, and the packet is dropped if the TTL reaches zero.
• Protocol: 8 bits that indicate the protocol of the data carried in the packet, such as TCP, UDP, ICMP, etc. The protocol numbers are defined in the List of IP protocol numbers.
• Header Checksum: 16 bits that provide error detection for the IP header. The checksum is calculated by adding the 16-bit words of the header and taking the one’s complement of the result.The checksum is recomputed and verified at each hop.
• Source IP Address: 32 bits that indicate the IP address of the sender of the packet.
• Destination IP Address: 32 bits that indicate the IP address of the receiver of the packet.
• Options: Variable-length field that contains optional information for the IP packet, such as security, routing, timestamp, etc. The options are padded with zeros to make the header length a multiple of 32 bits.

The IPv4 header can be distinguished from other protocol headers by the value of the Version field, which is 4 for IPv4. Other protocol headers have different values for the Version field or do not have a Version field at all. For example, the IPv6 header has a Version field of 6, the UDP header does not have a Version field, the Ethernet header has a Type field instead of a Version field, and the TCP header has a Data Offset field instead of a Version field. References:

• Aruba Certified Network Technician (ACNT) | HPE Aruba Networking
• Aruba Documentation Portal
• Introduction and IPv4 Datagram Header - GeeksforGeeks
• Protocol header - Oxford Reference
• List of IP protocol numbers - Wikipedia

The end command is used to exit from any configuration context and return to the manager context. The manager context is indicated by the # symbol at the end of the prompt. The manager context allows you to execute commands that do not require saving changes to the configuration, such as show or clear commands. The disable command is used to exit from the manager context and return to the operator context, which is indicated by the > symbol. The quit and exit commands are used to exit from the current context and return to the parent context, such as from config-if to config. However, these commands do not move you directly to the manager context from any configuration context. Therefore, the correct answer is A. end. References: Navigating to the manager context (#) - Aruba, Manager context (#) - Aruba

Layer 2 encapsulation is the process of adding a header and a trailer to the data coming from the upper layer (Layer 3) before sending it over the physical medium. The header and the trailer contain information such as source and destination MAC addresses, error detection, and protocol type. The devices that perform Layer 2 encapsulation are usually switches, bridges, or network interface cards (NICs). In the given network diagram, the PC is sending a message to the server. The PC first adds a Layer 2 header and trailer to the data and sends it to Switch-1. Switch-1 performs Layer 2 encapsulation again before forwarding it to the router. The router operates at Layer 3 and does not perform Layer 2 encapsulation. It only removes the Layer 2 header and trailer, checks the destination IP address, and forwards the packet to the next hop. The packet then reaches Switch-2, where Layer 2 encapsulation occurs again before it is sent to the server. The server also performs Layer 2 de-encapsulation by removing the header and trailer and passing the data to the upper layer. Therefore, the devices that have performed Layer 2 encapsulation by the time the message arrives at the server are Switch-1 and Switch-2. References: Understanding Data Link Layer Encapsulation, How Data Encapsulation & De-encapsulation Works?, HDLC Protocol and Encapsulation method Explained

The Institute of Electrical and Electronics Engineers (IEEE) is an organization that develops and publishes international standards for various fields of engineering, including electrical, electronic, computer, software, and telecommunications. IEEE standards are widely used and recognized by the industry, academia, and governments. IEEE standards cover topics such as wireless networking, Ethernet, power systems, smart grid, cybersecurity, robotics, biomedical engineering, and more. IEEE standards are developed by consensus among experts from different sectors and regions, and are reviewed and updated regularly to reflect the latest technologies and best practices. IEEE standards aim to promote innovation, interoperability, safety, reliability, and efficiency in engineering applications. References: IEEE Standards Association, IEEE - Wikipedia, IEEE Standards - Creative Safety Supply

 A switch is a device that operates at the data link layer (Layer 2) of the OSI model. It is responsible for forwarding frames based on the MAC addresses of the source and destination devices. A switch can also perform media access control, VLAN tagging, QoS, and other Layer 2 functions. A router, on the other hand, operates at the network layer (Layer 3) and routes packets based on their IP addresses. A transceiver is a device that converts electrical signals to optical signals and vice versa, and operates at the physical layer (Layer 1). A UTP cable is a type of twisted pair cable that is also used at the physical layer to transmit data. References: Data link layer - Wikipedia, Data Link Layer | Layer 2 | The OSI-Model, What is Layer 2? - Definition from Techopedia, An Overview of Layer 2 Ethernet – What is it and why does it matter?

 Aruba Central is a cloud-based networking solution that offers simplicity, security, and scalability for managing Aruba network infrastructure. It uses HTTPs to communicate with networking equipment such as wireless, wired, VPN, and SD-WAN devices. It also provides AI-powered insights, workflow automation, and advanced security features to unifyoperations across campus, branch, data center, and remote work environments. Aruba Central does not require an on-premises server, nor does it use SNMP for management. It also does not support third-party networking equipment, as it is designed for Aruba ESP (Edge Services Platform). References: Aruba Central for Cloud-managed networking, About Aruba Central, Aruba Central data sheet