The flexibility of the modern world of work raises new challenges for administrators concerning planning and maintenance of network structures. The occupation of the rooms by leaseholders changes permanently in public office buildings, and also inside of a company, teams are often newly assembled. In both cases, the individual units must have an independent, protected LAN. But this task is very burdensome to realize by hardware changes, or even not at all, because e.g. only one single central cabling exists in the office building.
Virtual LANs enable to perform this task in a very smart way. Also when departments or companies change at a later time inside of the building, the network structure can be easily adjusted.
All network users in this example use the central Ethernet, which is, like the connected devices, supervised by a service provider. Company A has three departments on two floors. The sales department can communicate with the administration department via VLAN ID 3, the accounts department with the administration via VLAN ID 5. The networks of accounts department and sales do not see each other. Company B is also shielded by VLAN ID 11 against all other networks, only the service provider can access all devices for maintenance purposes.