Introduction to VLAN, Its types, Range and Advantages.

In networking, as we know, switches are used to create networks, while routers are used to connect different networks. By default, switches forward both broadcast and multicast out of every port but not the originating one. However, if you require to divide a single broadcast domain into smaller ones with security in some networks, then it is possible with the VLAN concept. In this blog, we will understand what is VLAN and everything else you need to know about it.

A broadcast sent from a host can easily reach all network devices in the absence of VLANs. Every device will process received broadcast frames. It can potentially increase CPU overhead on each device while decreasing overall network security.

In case you place some interfaces on switches into separate VLANs, a broadcast from one host can reach only devices available inside the same VLAN. Hosts of VLANs will not even be aware that the communication took place, and all departments or groups work separately with their broadcast domain.

Before VLAN working of a switch

After VLAN working of a switch

What is VLAN?

VLAN stands for Virtual Local Area Networks; they are nothing but a logical grouping of switch ports to have separate broadcast domains. VLAN reduces the size of broadcast domains while increasing the number of broadcast domains.

VLANs are typically configured on switches by assigning some interfaces to one broadcast domain and others to another. Each VLAN serves as a subset of the switch ports on an Ethernet LAN.

VLANs can be configured on multiple switches, with each VLAN being treated as its own subnet or broadcast domain. The broadcasted frames onto the network will only be switched between the same VLAN ports.

VLAN Basics

• VLANs in networking are identified by a unique number called VLAN ID.
• A Valid ID range is 1-4094. On a VLAN switch, you assign ports with the proper VLAN ID.
• The switch then allows data that must be sent between various ports with the same VLAN ID.

Let's take a deep dive into VLAN, starting with VLAN Range.

VLAN Range

Moving on, let's understand the advantages of VLAN.

Advantages of VLAN

• Broadcast Control – eliminates unnecessary broadcast traffic by improving network performance and scalability.
• Improves Performance by reducing the size of the broadcast domain.
• Security – logically separates users and departments, allowing administrators to configure separate security for each VLAN.
• Flexibility – removes the physical boundaries of a network, allowing a user to exist anywhere.

These are some advantages of VLAN. It's time to understand different types of VLAN.

Types of VLAN

1. Default VLAN

When the switch first boots up, all switch ports are added to the default VLAN. Generally, all switches have default VLAN as VLAN 1. VLAN1 allows any network device connected to any switch port to connect with other devices on other switch ports. The VLAN1, i.e., Default VLAN, can't be renamed or deleted.

2. Data VLAN

Data VLAN is also known as a user VLAN. The data VLAN is only used for data generated by users. This VLAN carries data only. It does not carry management traffic or voice.

3. Voice VLAN

Voice VLAN is configured to carry voice traffic. Voice VLANs typically have higher transmission priority than most other types of network traffic. We need a separate voice VLAN to save bandwidth for other applications.

4. Management VLAN

A management VLAN is used to configure the switch for management purposes. It manages system logging and monitoring. By default, VLAN 1 is the management VLAN.

5. Native VLAN

This VLAN is used to carry untagged (not belonging to any VLAN) traffic.

These are the five types of VLAN. Now, let's get an overview of VLAN ports.

VLAN Ports

There are two types of ports used in VLANs -

1. Access Port

The access port is a member of only a single VLAN. By default, all switch ports on the Cisco switch are access ports. So, any device connected to any switch port becomes a member of that VLAN.

2. Trunk Port

When VLANs are configured on multiple switches, a mechanism is required to identify which VLAN a frame belongs to. This is accomplished through frame tagging, which adds a VLAN ID in each frame. These tagged frames are sent over Trunk ports.

If you are still with us, we are sure you have learned most things about VLAN. If you have any suggestions or feedback for us, you can comment down in the comment box. We would love to hear from you.

For more useful insights, you can also check out this video,

Conclusion – In this article, we have discussed what is VLAN, what are the different types of VLAN, its advantages and range. You can Join our CCNA Training for a better understanding of VLAN. Our CCNA training is rated among the top CCNA training in India and we have also launched a free CCNA program to help all aspiring network engineers.

To conclude, VLAN is showing a promising future in the networking field and this knowledge will be beneficial for any network engineer.