What is the function of a switch in an Ethernet network?

In an Ethernet network, the primary function of a switch is to segment collision domains. This means that each port on the switch creates its own collision domain, allowing devices connected to the switch to communicate simultaneously without interference. By doing this, switches enhance the overall performance and efficiency of the network.

When a switch receives a data frame, it examines the MAC address in the frame to determine its destination. Based on this address, the switch forwards the frame only to the specific port connected to the destination device. This selective forwarding helps to reduce unnecessary traffic on the network and optimizes bandwidth usage.

This segmentation allows multiple devices to communicate independently at the same time, significantly reducing collision occurrences compared to a hub-based setup, where all devices share a single collision domain. Thus, the ability of a switch to create separate collision domains is essential for maintaining effective communication between devices in an Ethernet network.