Virtual LAN (VLAN)

Virtual LANs (VLANs) is a concept wherein a physical LAN is divided into logical "LANs" that share the same physical wiring. Devices communicating on the same Virtual LAN are able to communicate with one another, but are logically separated from devices communicating on the same wire, but utilizing a different VLAN ID.

VLANs may be created by:

• Assigning a port on a switch with a particular VLAN ID or set of IDs
• Assigning MAC addresses to particular VLANs
• Mapping ▲layer 3 protocols to a particular VLAN
• Mapping Ethernet packets to ATM cells by using LAN Emulation (LAME)

VLANs are defined in IEEE 802.1Q.