CISSP Practice Exam 2025 – Complete Prep Guide

The primary characteristic of Virtual Local Area Networks (VLANs) is that they permit the establishment of multiple logical networks on a single physical network infrastructure. This means that VLANs can compartmentalize network segments, which enhances security, improves traffic management, and reduces broadcast domains without requiring separate physical hardware for each segment.

VLANs utilize tagging protocols, such as IEEE 802.1Q, to differentiate between the various logical networks as data packets traverse the same physical media. This capability allows organizations to segment networks by department, function, or any other criteria, creating more efficient network configurations and improving overall network organization and performance.

The other choices describe concepts that are less aligned with the foundational purpose of VLANs. While VLANs can lead to improved network performance by reducing unnecessary broadcast traffic, stating that they always increase network speed lacks nuance, as network performance depends on various factors. Additionally, VLANs do not have to be associated with additional hardware; instead, they work within existing switches and routers to create logical separations over physical infrastructure. The premise of physical networks does not accurately reflect the function of VLANs, which are fundamentally about logical separation rather than physical constructions.