13 minA VLAN is a logical Layer 2 broadcast domain created by configuration on managed switches. VLANs let one physical network behave as multiple isolated networks, controlling which devices can talk to which others, reducing broadcast traffic, and supporting the segmentation that security and compliance frameworks require. This guide covers what VLANs are, how they work at the protocol level, the common VLAN types, configuration patterns across vendors, troubleshooting, real-world use cases, and how to monitor multi-VLAN environments at scale.
