TestOut LabSim A+ Certification Practice Exam

Which of the following LAN devices receives a signal on one port and forwards that signal only to the port where the destination device is connected?

1. Router

2. Hub

3. Switch

4. Bridge

The correct answer is: Switch

A switch is a critical device in local area networks (LANs) that operates on the data link layer of the OSI model. It functions by allowing multiple devices to communicate on a network by intelligently forwarding data only to the port associated with the specific destination device. This means that when a switch receives a signal on one of its ports, it examines the data packet's MAC address and consults its MAC address table, which maps each MAC address to the corresponding port. It then forwards the data only to the intended recipient's port, reducing unnecessary traffic and collisions on the network. In contrast, a hub broadcasts incoming data packets to all connected devices, regardless of the intended recipient, leading to potential network congestion and collisions. A router, while capable of directing data across different networks based on IP addresses, functions at a higher network layer and does not operate at the requisite depth for intra-LAN communication. A bridge, while it can connect and filter traffic between two network segments, does not have the same level of efficiency as a switch in managing multiple devices on a single network. Thus, the switch is the most effective device for this task.