Chapter 9 Vlan Configuration; Introduction To Vlan - Digitalchina Networks DCS-3950 series Manual

Chapter 9 VLAN Configuration

9.1 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 DCS-3950
series 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.
Switch
VLAN1
Server
VLAN2
IBM PC
Laser Printer
VLAN3
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
DCS-3950 series Ethernet switch manual
Server
IBM PC
Fig 9-1 A VLAN network defined logically
Switch
Server
Desktop PC
Switch
IBM PC
Desktop PC
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