User's Manual

Key Concepts 501
Figure 259 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 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 end station must be updated
manually. With a VLAN setup, if an end station 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.
■ VLANs help to control traffic. If a bridge port in a traditional LAN
switching device receives a packet with a broadcast, multicast, or
unknown destination address, it forwards the packet to all other
bridge ports. This process is referred to as bridge flooding. As