For example, your marketing personnel may be spread throughout a building, yet if they are all assigned to a single VLAN, they can share resources and bandwidth as if they were connected to the same segment. Such a logical grouping helps free IT managers from the restrictions of their existing network design and cabling infrastructure and offers a fundamental improvement in the ease with which LANs can be designed, administered and managed. Users and resources that communicate most frequently with each other can be grouped in common VLANs so that their traffic is contained. Software-based VLANs mean changes do not require a visit to the wiring closet. Logical groupings allow network structure to quickly and easily adapt to an addition, relocation or reorganization of nodes through a management console.
Employees move, business operations are restructured and new technologies emerge.
All of these changes add pressure to networks already straining under the requirements of more users, more powerful workstations and more demanding applications. By offering a highly flexible means of segmenting a corporate network, VLANs reduce the performance bottlenecks that occur when traditional backbone routers can't meet the demands of fast, switched networks. For example, all marketing personnel may be spread throughout a building. The resources of other departments can be invisible to the marketing VLAN members, accessible to all, or accessible only to specified individuals, at the IT manager's discretion. This logical grouping of network nodes helps free IT managers from the restrictions of their existing network design and cabling infrastructure.