802.1Q (or Virtual LAN) is a venture under IEEE (Institute of Electrical and Electronics Engineers) 802 standards. This project provides a mechanism with the capacity to bridge several networks to share a physical network link while prohibiting data leakage between them.

802.1Q is also an interchangeable term used to refer to the standard issued by this project. It also pertains to procedures applied in the mechanism of Ethernet networks.

As a standard, IEEE’s 802.1Q screens large networks into smaller components to minimize bandwidth use by broadcast and multicast traffic. This standard also contributes to a higher level of privacy between various internal segments within networks.

The 802.1Q procedure provides a typical way of introducing VLAN membership data to Ethernet frames. In a Local Area Network (LAN), multicast and datalink-layer broadcast traffic transmitted to every end station. The traffic does not pass the LAN boundaries despite the fact that the perimeter shares cables or hubs.

IEEE 802.1Q explains the meaning of VLAN based on the specific model bridging at MAC (Media Access Control) level and the 802.1D spanning tree protocol. This procedure allows individual VLAN communication using Layer-3 routers.

If a company’s IT department wants to offer individual logical networks per specific department within the company while using one corporate network, VLAN will enable this route. Edge switches in the corporate network insert specific VLAN tags into the data frames coming from the equipment to and from any given department. The edge switches also removes the VLAN tags before the frames reach the specific department’s equipment (after switching off the frames in the corporate network). This ensures protection of one department from another.