VLAN Full Form

Last Updated : 07 Nov, 2024

A Virtual Local Area Network (VLAN), is one of the network configuration technique. It allows for logical segmentation of the physical LAN into multiple distinct domains of broadcast. It enables a network manager to group the devices based on the function, department, or application regardless of the physical location. This leads to better organization and network efficiency. VLANs optimize the performance of a network by minimizing congestion and isolating traffic, thus proving better utilization of bandwidth, improvement in security, and better management of the network. VLANs help the business organizations adapt to growing demands of the network and reduce network complexity.

The IEEE 802.1D-2004 standard played a part in the evolution of Ethernet LANs to VLANs to keep up with the increasing transmission demands. This was made possible through the concept of bridging which divides a single physical LAN into two or more VLANs. Before this, it was impossible to have two systems have the same IP address on the same physical network.

Types of VLAN

Default VLAN: The VLAN all switch ports are by default a member of it unless any other VLAN has been configured (usually VLAN 1).
Data VLAN: A VLAN specifically used for data traffic usually to separate user devices by function or departments.
Voice VLAN: A VLAN dedicated for voice traffic like VoIP for high quality and low interference and data traffic.
Management VLAN: This VLAN is accessed for management interfaces of various networking devices such as switches and routers to ensure that they are accessed in a secure way.
Native VLAN: The VLAN used to carry traffic that's not tagged on a trunk port.
Private VLAN: The VLAN is so designed that devices within the same VLAN are isolated for better security.

Characteristics of VLAN

Each VLAN acts as a separate LAN. This reduces the congestion by sharing the traffic between the VLANs.
VLANs can span multiple switches.
VLANs make it easier to relocate terminals.

Advantages of VLAN

VLANs use bandwidth with more efficiency compared to LANs.
As they are confined to their respective broadcast domains, they reduce traffic on a network.
Each group is assigned a different broadcast domain hence there is added security to prevent confidential information from being seen by other groups.
It reduces the need for expensive routers hence they reduce the overall cost.

Disadvantages of VLAN

Managing larger networks can be complex.
When you need to add a new VLAN, you need to configure all the switches to accommodate it.
VLAN's interoperability can be complex as well.

VLAN Management and Configuration

VLANs can be implemented by various network switches and routers that support VLANs. The general process of implementing a VLAN generally encompasses:

VLAN IDs definition assign a unique VLAN ID to each VLAN.
Configure Ports: Give access or trunk ports for all VLANs.
Device Assignment: Assign devices to the VLAN appropriate for their functionality in the network.
Routing Between VLANs: If communicating devices reside on different VLANs, a Layer 3 device, such as a router, must route the traffic between VLANs.

VLAN Port

A VLAN port is a physical or logical interface on a switch that is set to be part of a given VLAN. There are two variants of VLAN ports.

Access Ports: An assigned port for one VLAN, to connect end devices like computers and printers to the VLAN.
Trunk Ports: These are types of ports which carry traffic from multiple VLANs on a link, usually between switches. A trunk port can carry traffic from all VLANs in the network.

Conclusion

VLAN is simply a networking solution that divides a physical LAN into multiple smaller, logical networks, which act as separate broadcast domains. The network performs better because there is less congestion, the network is more secure due to isolation of the traffic, and bandwidth efficiency is higher. VLANs offer flexibility because more than one logical network can coexist over the same physical infrastructure and, therefore, reduces costs associated with routers.