Functions of a VLAN: logically different users within the same physical LAN into different broadcast domains, help control the flow, reduce equipment investment, simplify network management, improve the security of the network.
VLAN features:
1) segment of: a segmented network, reducing the number of hosts for each zone, to improve network performance;
2) Flexibility: Under normal circumstances without changing the physical network and to add a new device to change the wiring system;
3) Safety: Communication between VLAN is done in a controlled manner.