64 CHAPTER 8: SETTING U P VIRTUAL LANSFigure 14 A network setup showing three VLANsBenefits of VLANs The main benefit of VLANs is that they provide a network segmentationsystem that is far more flexible than any traditional network. Using VLANsalso provides you with three other benefits:■ VLANs ease the movement of devices on networksWith traditional networks, network administrators spend much oftheir time dealing with moves and changes. If users move to adifferent subnetwork, the addresses of each endstation must beupdated manually.With a VLAN setup, if an endstation in VLAN Marketing for example ismoved to a port in another part of the network, and retains its originalsubnet membership, you only need to specify that the new port is inVLAN Marketing. You do not need to carry out any re-cabling.■ VLANs provide extra securityDevices within each VLAN can only communicate with other devices inthe same VLAN. If a device in VLAN Marketing needs to communicatewith devices in VLAN Finance, the traffic must pass through a routingdevice or Layer 3 Switch.VLAN 1VLAN 3VLAN 2Marketing DepartmentDevelopment DepartmentFinance DepartmentSwitch A Switch BBackbone connecting multiple switches1 12 23 34 45 56 67 78 8
