A VLAN is a group of network services not restricted to a physical segment or LAN switch.

VLANs logically segment switched networks based on the functions, project teams, or applications of the organization regardless of the physical location or connections to the network. All workstations and servers used by a particular workgroup share the same VLAN, regardless of the physical connection or location.

Configuration or reconfiguration of VLANs is done through software. Physically connecting or moving cables and equipment is unnecessary when configuring VLANs.

A workstation in a VLAN group is restricted to communicating with file servers in the same VLAN group. VLANs function by logically segmenting the network into different broadcast domains so that packets are only switched between ports that are designated for the same VLAN. VLANs consist of hosts or networking equipment connected by a single bridging domain. The bridging domain is supported on different networking equipment. LAN switches operate bridging protocols with a separate bridge group for each VLAN.

VLANs are created to provide segmentation services traditionally provided by physical routers in LAN configurations. VLANs address scalability, security, and network management. Routers in VLAN topologies provide broadcast filtering, security, and traffic flow management. Switches may not bridge any traffic between VLANs, as this would violate the integrity of the VLAN broadcast domain. Traffic should only be routed between VLANs.

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