VLAN stands for “Virtual Local Area Network” and refers to a virtual, purely logical network that is based on a physical network infrastructure. It acts as a smaller segment within a large, wired network and enables location-independent connection in the same LAN.
VLANs are usually implemented using managed switches. Each VLAN has its own broadcast domain, which enables the transmission of broadcasts/data packets. There are different variants of VLANs, with port-based VLANs and tagged VLANs being the most common. Port-based VLANs perform a logical segmentation in which individual ports are assigned to a VLAN. This configuration is mainly used in small networks, whereby the implementation does not necessarily take place on a single switch. In this case, additional switches must be connected to each other with a cable. Tagged VLANs, on the other hand, work at frame level, whereby a “tag” within the message frame is responsible for the assignment. This tag contains all the information about the location and enables communication. A port can be assigned to several VLANs.
This structure facilitates the organization in a company, as data exchange can be made more flexible and clearer. Spatial flexibility is also provided, as users remain in the same VLAN despite a change of location. In addition, managing the bandwidth via the VLAN enables targeted control of broadcast traffic, which leads to efficient use of network resources. Overall, VLANs also offer basic security through the separation of data traffic and increased resistance compared to physical networks.