What is VLAN and what are its most important functions?

macfranc007 September 27, 2017 Nigeria News today & Breaking news ▷ Read Nigerian newspapers 24/7 Francis Ladipo

For the last decade, VLANs have played an major role in allowing companies to separate their network into multiple segments. However, the concept of a VLAN is still shrouded in mystery in the eyes of an ordinary PC user. Do you want to find out what is a VLAN and its purpose? Continue reading this article to learn all about VLAN!

What is VLAN?

A VLAN (or a Virtual Local Area Network) is a subnetwork that create numerous groups, consisting of individual devices that are originally connected to different physical LANs. Virtual LANs are most commonly used by huge corporations or IT companies that require re-grouping and dividing their primary network for security and more streamlined traffic management.

As we enter the era of cloud networks, understanding the mechanics of what does a VLAN do is even more important. They are essential in managing the ever-increasing virtualization of the business world.

Let’s explain the main difference between the two types of local networks by using a couple of pictures. First, let’s look at how information is shared without a VLAN.

Without a virtual LAN, a file that was sent through a physical network would reach all the devices connected to the switch. Thus, there’s nothing you can do if the information was meant only for a particular person.

Now let’s take a look at how the same process works on a virtual network.

As you can see, this time the data only reached the host B, bypassing all the unnecessary devices.

Interesting fact: Both the Ethernet and Wi-Fi physical networks support the creation of VLANs.

If you hired a professional to create a VLAN, it could bring numerous benefits to the overall workflow of a company’s network. Let’s list the three most significant advantages of using a VLAN:

They allow setting up groups of devices that transfer data to each other on a constant basis.
They handle the traffic split between devices from different physical networks with more elegance and speed by using switches.
They grant more security, as you have control over who receives what information.

Tip: If you want to add even more efficiency to the workflow, combine using a VLAN with server virtualization. This way you can combine and share information from different physical servers.

We won’t explain VLAN configuration in detail, but it needs to be mentioned that there are three ways of configuring a virtual network – static, dynamic and port-centric. The main process of configuration happens on switches, where you can combine different devices into numerous domains. You can also transmit a VLAN across multiple switches.

There’s no clear best option here. Although, the accepted rule is that static configuration is better for security, while a dynamic VLAN allows more flexibility.

The static variant demands the administrator to allocate separate ports on the network switch to a VN. This option has a disadvantage as any device that is assigned to that port automatically becomes a part of the same VLAN. In most cases, that shouldn’t be too much of a problem, but a dynamic virtual network is still preferable. It allows adding and deleting network members based on the various features of the devices used and not on the location of the switch.

It’s also important to know that each port on a particular switch can be set to act either as an access point or a trunk port. The first one can be assigned to a single VLAN, while the latter acts as a bridge between switches and is used to transfer data over multiple VLANs.

For some time, there was also a debate between those who use IP subnetting and the more progressive VLAN users. The key benefit of using the latter is that it provides more security. And what is more important for a large company, especially in the IT sector, if not how secure their information is?

Purpose of Native VLAN

There are two main standards for virtual network administration: Native VLAN and Management VLAN. The one that usually raises more questions is the Native VLAN, so let’s talk more about it.

A Native LAN is a combination of all the untagged frames, and its default name is VLAN 1. The primary purpose of it is to serve as a trunk. When you buy a new switch, VLAN 1 (Native VLAN) is the only network that exists on it. Thus, all the ports are its members by default. Next, you begin to create other VLANs and a Native VLAN is used only to transfer unassigned information.

To help you understand this concept better, we’ll provide an example. Imagine that you have a port hosting VLANs 3, 4, and 5, while VLAN 1 is your native one. Any data received on that port that has a specific tag (3, 4 or 5) will be sent to that VLAN. However, if the data is untagged, it will be transferred to VLAN 1.

Tip: The general rule is not to use VLAN 1 as your native network, as it leads to security problems. It’s better to rename it to a different number, to avoid any problems. This way, if an intruder or an uninvited guest makes his way to VLAN 1, there’s nothing there to steal.

Now you know the main functions and benefits of using a VLAN. As you can see, virtual networks are going to stay in our lives for a while, so be sure to share this information with your friends.