User Manual

Moxa’s Managed Switch Next Generation OS (v3.x) User Manual

IEEE 802.1Q Overview

The IEEE 802.1Q is a network communication protocol that falls under the IEEE 802.1 standard regulation,

allowing various segments to use a physical network at the same time to block broadcast packets by

different segmentations. It specifies the VLAN tagging for Ethernet frames on switches that can control the

path process.

How A VLAN Works

What is a VLAN?

A VLAN is a group of devices that can be located anywhere on a network, but which communicate as if they

are on the same physical segment. With VLANs, you can segment your network without being restricted by

physical connections—a limitation of traditional network design. With VLANs you can segment your network

into:

• Departmental groups—You could have one VLAN for the marketing department, another for the

finance department, and another for the product development department.

• Hierarchical groups—You could have one VLAN for directors, another for managers, and another for

general staff.

• Usage groups—You could have one VLAN for email users and another for multimedia users.

Benefits of VLANs

The main benefit of VLANs is that they provide a network segmentation system that is far more flexible than

traditional networks. Using VLANs also provides you with three other benefits:

• VLANs ease the relocation of devices on networks: With traditional networks, network

administrators spend much of their time dealing with changes. If users move to a different subnetwork,

the addresses of each host must be updated manually. With a VLAN setup, if a host originally on the

Marketing VLAN is moved to a port on another part of the network, and retains its original subnet

membership, you only need to specify that the new port is on the Marketing VLAN. You do not need to

do any re-cabling.

• VLANs provide extra security: Devices within each VLAN can only communicate with other devices

on the same VLAN. If a device on the Marketing VLAN needs to communicate with devices on the

Finance VLAN, the traffic must pass through a routing device or Layer 3 switch.

• VLANs help control traffic: With traditional networks, congestion can be caused by broadcast traffic

that is directed to all network devices, regardless of whether or not they need it. VLANs increase the

efficiency of your network because each VLAN can be set up to contain only those devices that need to

communicate with each other.