A Virtual LAN (VLAN) is a logical grouping of devices on a network that appear to be on the same physical LAN, regardless of their physical location.
- VLANs are implemented to segregate network traffic for better security, performance, and manageability.
- Devices on different VLANs cannot communicate directly unless explicitly allowed.
Benefits of Virtual LANs
- It provides improved security by reducing unauthorized access and potential data breaches
- It enhances network performance by minimizing unnecessary network congestion and reducing broadcast traffic.
- It is cost-effective as it reduces the need for additional network hardware, utilizing existing equipment for logical segmentation.
- It simplifies network management by allowing logical segmentation of networks without the need for physical cabling reconfiguration.
- It offers flexibility and scalability by enabling the grouping of devices based on function, department, or project, regardless of their physical location.
How VLANs Work
Logical Segmentation:
- A VLAN groups devices logically, not based on physical hardware connections. For example, employees in the same department can be on the same VLAN, even if they are in different buildings.
Tagging with VLAN IDs:
- VLANs use VLAN IDs to label packets. This tagging is typically done at the switch level using protocols like IEEE 802.1Q. The tag ensures that data is routed to the correct VLAN.
Switch Configuration:
- Managed switches are configured to support VLANs by assigning ports or devices to specific VLANs. Each VLAN is treated as a separate network.
Inter-VLAN Communication:
- Communication between VLANs is handled by a router or a Layer 3 switch. Without such a setup, devices on different VLANs cannot communicate.
