What Are Virtual Local Area Networks (VLANs)?

By George Rouse

Also known as Virtual Local Area Networks, VLANs are one of those key technologies in modern computer and internet connectivity that many people don’t fully appreciate or understand. We’re here to clear up some of the mystery by establishing what VLAN technology is, how it's used, and the role it plays in your daily tech needs.

A basic definition of a VLAN

Simply put, a Virtual Local Area Network is a logically interconnected collection of devices that are partitioned in a group. VLAN group members can be in the same building, different buildings, across campuses, or widely dispersed geographic locations that recognize their peers to be a part of the same Local Area Network. In essence, VLANs are not constrained by the means of connectivity used by the group member: physical wires, wireless, or cellular technologies.

What is the purpose of a VLAN?

In addition to device association, VLANs deliver data protection and security to enable confident connectivity and sharing between critical resources.

So, what are VLANs used for? As an example, a library or laboratory might have a number of computers, printers, and other devices connected together through cables and wireless connections for sharing files and documents among each other. These devices and their connectivity – through a router – together form a single local area network, or virtual LAN.

VLANs are extremely useful connectivity solutions for large, medium, and small businesses. In businesses, a number of different departments have their own local computing networks and want to connect them with each other without having to suffer the potential security breaches of openly using wider internet connectivity (even though many of these devices might indeed individually be connected to the internet).

The power of VLAN technology

With VLANs, you can have clusters of LAN-connected devices working all together across several different segments and departments as if they were each part of a single LAN. Each LAN segment is then separated from the other LAN segments of the VLAN by a router, switch, or bridging device.

This allows an organization to maintain secure internal communications across multiple departments without worrying as much as it otherwise would about data breaches or leaks. Many organizations use VLAN technology as the primary method of separating responsibilities and securing intellectual property to specific teams.

Another major use case of VLAN technology is collision avoidance for enormous amounts of data sharing. If you’re working with just a LAN, two or more devices on that same network trying to share data with other devices can easily cause collisions between the transmitted data.

These bottlenecks can then propagate all through the local area network and slow down data flow. If you expand the LAN more, this collision problem is likely to get worse, which would be a bad outcome for any busy, digital device-filled workplace.

What VLANs can do to help avoid this problem is expand connectivity and transmission options virtually, so that collisions happen less frequently. Data sent from one workstation through a VLAN passes through a virtual switch instead of a physical one. Each of these virtual switches is able to operate completely independently from other virtual switches in the network—this is crucial to how VLANs let multiple devices in the various LANs in the network send data amongst each other with minimal collisions.

VLANs offer more robust connectivity than normal LANs and let organizations group devices without worrying too much about their physical locations. As a result, devices can be grouped based on arbitrary criteria like project types, departments, work segments and more, without worrying about physical locations for each device.

So why would I want to use a VLAN?

There are many logically sound reasons why VLANs might work for your organization. VLANs offer flexibility while reducing logistical complexity or physical connectivity needs. Some other reasons they are useful include:

Cost effectiveness: With VLANs, many devices can communicate through virtual switches instead of physical routers or cables. This lets these device networks handle increased data loads with fewer bottlenecks and fewer physical installation or device costs.

Flexibility: Assign devices based on ports, protocols, arbitrary criteria or work requirements. This lets you control network connectivity criteria without the need for physical considerations like those of a LAN.

Lower administrative and IT logistics: Because VLANs rely on virtual connectivity, they require less IT involvement in reconfiguring network connection maps whenever the structure or workflows in your organization change. This reduces administrative expenses as your clients grow and evolve.

If you think that a VLAN is something your organization might benefit from offering to its growing IT clients, contact the professional client IT management experts at Datto for more information.

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