How VLANs work in networking

network vlans

Virtual Local Area Networks (VLANs) are a crucial component of modern computer networking. They provide network administrators with the ability to logically segment a single physical network into multiple virtual networks, each with its own set of security, traffic management, and broadcast domains. In this blog post, we’ll take a closer look at VLANs and how they work.

What are VLANs?

VLANs are a way of dividing a single physical network into multiple virtual networks. Each VLAN operates as a separate network, with its own set of rules and configurations. The devices within each VLAN can communicate with each other as if they were on a single physical network, but they are isolated from other VLANs, providing increased security and control over network traffic.

How do VLANs work?

VLANs work by tagging each network packet with a VLAN identifier (VID) that specifies which virtual network the packet belongs to. The VLAN identifier is stored in the packet’s header and is used by network switches to determine the VLAN to which the packet belongs.

Network switches use the VLAN identifier to route network traffic to the appropriate VLAN, allowing the switch to segregate traffic between VLANs. This means that a device in one VLAN cannot communicate directly with a device in another VLAN, unless a router is used to bridge the traffic between the two VLANs.

VLAN Configuration

VLAN configuration is usually done at the network switch level, although some network devices may also have VLAN configuration options. The process of configuring a VLAN involves creating a VLAN, assigning ports to the VLAN, and configuring the VLAN’s properties.

When configuring a VLAN, administrators can specify the VLAN identifier, which is used to identify the VLAN and differentiate it from other VLANs. Additionally, administrators can configure the VLAN’s traffic management and security settings, such as defining which ports can communicate with the VLAN, setting up firewall rules, and controlling broadcast domains.

Benefits of VLANs

VLANs provide several benefits, including:

  1. Increased security: VLANs allow administrators to segment a network into multiple isolated virtual networks, reducing the risk of unauthorized access to sensitive information.
  2. Better traffic management: VLANs allow administrators to control the flow of network traffic, making it easier to manage the network and avoid congestion.
  3. Improved scalability: VLANs allow administrators to add new devices to the network without affecting the existing network configuration, making it easier to scale the network as needed.
  4. Simplified network administration: VLANs provide a way to manage network resources and control network access, making it easier for administrators to manage the network.

VLANs are a key component of modern computer networking, providing network administrators with the ability to segment a single physical network into multiple virtual networks, each with its own set of security, traffic management, and broadcast domains. By using VLANs, administrators can improve network security, manage traffic more effectively, and simplify network administration.