CompTIA Network+ Practice Test

Which of the following best describes the role of a switch in a network?

1. Routes traffic between different subnets

2. Forwards traffic based on data link addresses

3. Encrypts data between two endpoints

4. Manages and controls network structure

The correct answer is: Forwards traffic based on data link addresses

A switch plays a crucial role in a network by forwarding traffic based on data link addresses, specifically using MAC (Media Access Control) addresses. When a data frame arrives at a switch, it examines the MAC address in the frame's header to determine the intended destination port. This allows the switch to intelligently direct traffic only to the appropriate device on the network, significantly improving efficiency and reducing unnecessary traffic on other segments. In contrast, routing traffic between different subnets is a function performed by routers, which operate at a higher layer in the OSI model. Encryption of data is typically handled by specialized devices or software designed for securing data transmissions, not by switches. Managing and controlling network structure encompasses a broad range of tasks that could involve various types of devices and protocols, not solely the function of a switch. Thus, the ability of a switch to forward traffic based on MAC addresses is its defining characteristic in network operations.