Pass the HP Aruba ACNT HPE3-U01 Questions and answers with CertsForce

 Adjacent Channel Interference (ACI) is a type of interference that occurs when two or more wireless devices use channels that are close to each other in the same frequency band. ACI reduces the signal quality and throughput of the wireless devices, as they have to compete for the same spectrum and deal with the noise from the neighboring channels12

The 5 GHz band has more non-overlapping channels than the 2.4 GHz band, which means that there is less chance of ACI in the 5 GHz band. However, ACI can still occur in the 5 GHz band if the wireless devices use wider channel bandwidths, such as 40 MHz or 80 MHz, which are supported by 802.11n and 802.11ac standards. Wider channel bandwidths can increase the data rate and performance of the wireless devices, but they also occupy more spectrum and reduce the number of available channels134

Therefore, one condition that allows 5 GHz channels to avoid ACI is to transmit at 20 MHz bandwidth, which is the narrowest channel bandwidth supported by 802.11a/n/ac standards. By transmitting at 20 MHz bandwidth, the wireless devices can use more non-overlapping channels in the 5 GHz band and minimize the impact of ACI. However, this alsomeans that the wireless devices will have lower data rates and performance than using wider channel bandwidths134

Another condition that can help avoid ACI in the 5 GHz band is to use channel bonding, which is a technique that combines two or more adjacent channels into one wider channel. Channel bonding can increase the data rate and performance of the wireless devices, but it also requires careful planning and coordination to avoid overlapping with other wireless devices. Channel bonding can be done with 40 MHz or 80 MHz channel bandwidths, but not with 20 MHz channel bandwidths134 References: 

https://www.ti.com/pdfs/bcg/80211_acr_wp.pdf

https://www.ti.com/pdfs/bcg/80211_acr_wp.pdf

Full-duplex is a switchport feature that allows simultaneous transmission and reception of data on a link, without causing collisions. Collisions occur when two devices try to send data at the same time on a shared medium, such as a half-duplex link or a hub. Full-duplex eliminates the need for collision detection and avoidance mechanisms, such as CSMA/CD, and increases the effective bandwidth of the link. Full-duplex requires both ends of the link to support and be configured for full-duplex mode. If one end is configured for full-duplex and the other for half-duplex, the result is a duplex mismatch, which causes performance issues and errors. Auto speed is a switchport feature that allows the switch to negotiate the speed of the link with the connected device, such as 10 Mbps, 100 Mbps, or 1000 Mbps. VLANs are logical groups of devices that share the same broadcast domain, regardless of their physical location or connection. VLANs can reduce collisions by segmenting the network and limiting the scope of broadcasts. However, VLANs alone do not prevent collisions on a link, as they depend on the duplex mode of the switchport. Half-duplex is a switchport feature that allows only one direction of data transmission at a time on a link, either sending or receiving. Half-duplex requires collision detection and avoidance mechanisms, such as CSMA/CD, to coordinate the access to the shared medium. Half-duplex reduces the effective bandwidth of the link by half, as only one device can use the link at a time. Half-duplex can cause collisions if two devices try to send data at the same time on the same link. References:

Aruba Certified Network Technician (ACNT) | HPE Aruba Networking

Aruba Documentation Portal

switch port collisions - Cisco Community

Why is a switch port a collision domain? - Cisco Community

The PCs are not able to successfully establish bidirectional communication because they are on different subnets and their default gateways are not configured correctly. The default gateway is the IP address of the router interface that connects to the same subnet as the PC. The default gateway allows the PC to send packets to destinations outside its own subnet. In this case, PC-1 and PC-2 are on the 172.16.30.0/24 and 172.16.31.0/24 subnets respectively, and the router interfaces are 172.16.30.254 and 172.16.31.254 respectively. Therefore, the correct default gateway for PC-1 is 172.16.30.254 and the correct default gateway for PC-2 is 172.16.31.254. Changing PC-2’s default gateway to 172.16.31.254 will enable the communication between PC-1 and PC-212 References:

Aruba Certified Network Technician (ACNT) - HPE Certification and Learning

Aruba Certified Network Technician (ACNT) - Aruba Networks.

 The 5 GHz band is a radio frequency band used for Wi-Fi communications. It has a higherdata bandwidth than the 2.4 GHz band, but a shorter range and less penetration through walls. The 5 GHz band is divided into several sub-bands, each with a different set of channels. One of these sub-bands is the U-NII-3 band, which covers the frequency range from 5725 MHz to 5850 MHz. This sub-band contains 24 non-overlapping channels, numbered from 149 to 172. Channels 149 to 161 are part of the 5 GHz band and can be used for Wi-Fi communications. Channels 165 and 169 are restricted to indoor use only, and channel 173 is not allowed in some regions. Channels 12, 13, and 14 are not part of the 5 GHz band, but belong to the 2.4 GHz band, which has a different set of channels and regulations. U-NII-5 is not a valid sub-band name, but a proposed extension of the 5 GHz band to include the frequency range from 5925 MHz to 7125 MHz. This extension is not yet approved or implemented, and therefore not part of the 5 GHz band. References: List of WLAN channels, What’s the Difference Between 2.4 and 5 GHz Wi-Fi (and Which Should I Use)?, What is the difference between 2.4 GHz, 5 GHz, and 6 GHz wireless frequencies?

The IP address 10.0.128.0/23 is a Class A private address with a subnet mask of 255.255.254.0. This means that the network prefix is 10.0.128.0 and the host identifier is the last 9 bits of the address. To find the number of IP assignable addresses, we need to subtract 2 from the total number of possible hosts, which is29=512. This is because the network address (10.0.128.0) and the broadcast address (10.0.129.255) are reserved and cannot be assigned to any host. Therefore, the number of IP assignable addresses is 512 - 2 = 510.References:IP Subnet Calculator,CIDR Calculator for IPv4 addresses,Free online IPv4 subnet calculator

The subnet mask 255.255.252.0 is equivalent to the CIDR notation /22, which means that 22 bits are used for the network prefix and 10 bits are used for the host part. To calculate the number of addresses that this subnet mask provides, we can use the formula2n−2, wherenis the number of bits in the host part. In this case,n=10, so the number of addresses is210−2=1024−2=1022. The subtraction of 2 is because the first and the last addresses are reserved for the network identifier and the broadcast address, respectively. Therefore, the subnet mask 255.255.252.0 provides 1022 usable addresses for hosts, plus 2 reserved addresses, for a total of 1024 addresses.References:IP Subnet Calculator,How many host addresses are available on the network … - ITExamAnswers

An omnidirectional antenna is an antenna that radiates almost equal power in all directions in the horizontal plane, which is also called the azimuth plane1. This means that the antenna has a 360-degree coverage in the horizontal plane, but a narrow coverage in the vertical plane, which is also called the elevation plane2. An omnidirectional antenna is suitable for indoor environments where the clients are distributed around the access point3. Therefore, statement D accurately describes an omnidirectional antenna. Statements A, B, and C are incorrect because they describe different types of antennas. Statement A describes an isotropic antenna, which is a theoretical antenna that radiates equal power in all directions in both the horizontal and vertical planes. Statement B describes a vertical antenna, which is an antenna that radiates almost equal power in all directions in the vertical plane, but a narrow coverage in the horizontal plane. Statement C describes a directional antenna, which is an antenna that radiates more power in a specific angle and less power in others, creating a focused beam of radio waves. References: 1: Aruba Certified Network Technician (ACNT) Study Guide, page 872: Aruba Certified Network Technician (ACNT) Study Guide, page 883: Aruba Certified Network Technician (ACNT) Study Guide, page 89. : Aruba Certified Network Technician (ACNT) Study Guide, page 87. : Aruba Certified Network Technician (ACNT) Study Guide, page 88. : Aruba Certified Network Technician (ACNT) Study Guide, page 89.

 The TCP three-way handshake is a process that is used in a TCP/IP network to create a connection between a client and a server. It involves the exchange of three packets: SYN, SYN-ACK, and ACK. The goal of the TCP three-way handshake is to establish a reliable, flow-controlled connection between the two endpoints. This means that the connection is able to ensure that the data is transmitted without errors, losses, or duplications, and that the data is sent at a rate that both sides can handle.

The TCP three-way handshake works as follows:

The client initiates the connection by sending a SYN packet to the server. The SYN packet contains a random sequence number that indicates the starting point of the data that the client will send.

The server responds to the client by sending a SYN-ACK packet. The SYN-ACK packet contains the server’s own sequence number and an acknowledgment number that is equal to the client’s sequence number plus one. This indicates that the server has received the client’s SYN packet and is ready to receive data from the client.

The client completes the handshake by sending an ACK packet to the server. The ACK packet contains an acknowledgment number that is equal to the server’s sequence number plus one. This indicates that the client has received the server’s SYN-ACK packet and is ready to send data to the server.

After the TCP three-way handshake is completed, the connection is established and the data transfer can begin.

References: The answer can be verified by using the following resources:

TCP 3-Way Handshake Process - GeeksforGeeks

TCP 3-Way Handshake (SYN, SYN-ACK,ACK) - Guru99

Akamai Blog | What is a TCP Three-Way Handshake?

What is a Three-Way Handshake? - Definition from Techopedia

What is TCP 3-Way Handshake, Benefits, and Drawbacks? - Networking Signal

The digits in the ArubaOS-CX switch interface numbering represent the member, slot, and port numbers of the physical ports and their corresponding logical software interfaces. The format is member / slot / port, where:

Member: Member number of the switch in a Virtual Switching Framework (VSF) stack. Range: 1 to 8. The primary switch is always member 1. VSF is a technology that allows multiple switches to operate as a single logical device, providing high availability, scalability, and simplified management.

Slot: Slot number of the module on the switch chassis. Range: 1 to 6. The 6400 Switch Series has six slots for line cards, while the 8320, 8325, and 8400 Switch Series have four slots for line cards and two slots for management modules.

Port: Port number of the interface on the module. Range: 1 to 48 for 1G/10G ports, 1 to 32 for 25G ports, and 1 to 8 for 40G/100G ports.

For example, interface 1/1/1 refers to the first port on the first module of the first switch in a VSF stack.

References:

Identifying switch ports and interfaces

ArubaOS-CX 10.05 Command-Line Interface Guide 6200 Switch Series

ArubaOS-CX 10.04 Virtual Switching Extension (VSX) Guide

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/