User's Manual

15-9
Chapter 15 VLAN Configuration
15.1 VLAN Configuration
15.1.1 Introduction to VLAN
VLAN (Virtual Local Area Network) is a technology that divides the logical addresses of devices within the
network to separate network segments basing on functions, applications or management requirements. By
this way, virtual workgroups can be formed regardless of the physical location of the devices. IEEE
announced IEEE 802.1Q protocol to direct the standardized VLAN implementation, and the VLAN function of
switch is implemented following IEEE 802.1Q.
The key idea of VLAN technology is that a large LAN can be partitioned into many separate broadcast
domains dynamically to meet the demands.
Figure 15-1 A VLAN network defined logically
Each broadcast domain is a VLAN. VLANs have the same properties as the physical LANs, except VLAN is a
logical partition rather than physical one. Therefore, the partition of VLANs can be performed regardless of
physical locations, and the broadcast, multicast and unicast traffic within a VLAN is separated from the other
VLANs.
With the aforementioned features, VLAN technology provides us with the following convenience:
 Improving network performance
 Saving network resources
 Simplifying network management
 Lowering network cost
 Enhancing network security
Switch
Switch
Switch
Server Server Server
PC
PC PC
PC PC
Laser Printer
VLAN1
VLAN2
VLAN3