3Com 3824 - Benefits of VLANs

64 CHAPTER 8: SETTING UP VIRTUAL LANS
Figure 16 A network setup showing three VLANs
Benefits of VLANs The main benefit of VLANs is that they provide a network segmentation
system that is far more flexible than any traditional network. Using VLANs
also provides you with three other benefits:
■ VLANs ease the movement of devices on networks
With traditional networks, network administrators spend much of
their time dealing with moves and changes. If users move to a
different subnetwork, the addresses of each endstation must be
updated manually.
With a VLAN setup, if an endstation in VLAN Marketing for example is
moved to a port in another part of the network, and retains its original
subnet membership, you only need to specify that the new port is in
VLAN Marketing. You do not need to carry out any re-cabling.
■ VLANs provide extra security
Devices within each VLAN can only communicate with other devices in
the same VLAN. If a device in VLAN Marketing needs to communicate
with devices in VLAN Finance, the traffic must pass through a routing
device or Layer 3 Switch.
VLAN 1
VLAN 3
VLAN 2
Marketing Department
Development Department
Finance Department
Switch A
Switch B
Backbone connecting multiple switches
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