HPE3-U01 Exam Dumps : Aruba Certified Network Technician Exam (ACNT)

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.

A collision occurs when two or more devices try to transmit data at the same time on a shared medium, such as a bus or a hub. Collisions degrade network performance and cause data loss. Switches mitigate collisions by creating separate collision domains for each port. This means that each port can transmit and receive data without interfering with other ports. Switches also use full-duplex communication, which allows simultaneous transmission and reception of data on each port, further reducing the chances of collisions. VLANs and L3 protocols do not affect collisions, as they operate at different layers of the network model. Proprietary features are not a general characteristic of switches, and may not be compatible with other vendors’ switches. References: Aruba Certified Network Technician (ACNT) | HPE Aruba Networking, Aruba Documentation Portal

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