3Com Switch 8800 Family Configuration Guide

7
VLAN CONFIGURATION
VLAN Overview Virtual local area network (VLAN) groups the devices in a LAN logically, not
physically, into segments to form virtual workgroups. IEEE issued the IEEE 802.1Q
in 1999 to standardize the VLAN implementations.
The VLAN technology allows network administrators to logically divide a physical
LAN into different broadcast domains or the so-called virtual LANs. Every VLAN
contains a group of workstations with the same demands. The workstations,
physically separated, are not necessarily on the same physical LAN segment.
You can establish VLANs of the following types on switches:
■ Port-based
■ IP multicast-based (A multicast group can be a VLAN.)
■ Network layer-based (A VLAN can be established by the network layer
addresses or protocols of the hosts.)
With the VLAN technology, the broadcast and unicast traffic within a VLAN will
not be forwarded to other VLANs. This is helpful to control network traffic, save
device investment, simplify network management and enhance security.
Configuring VLAN The following sections describe VLAN configuration tasks:
■ “Creating/Deleting a VLAN”
■ “Specifying a Description Character String for a VLAN or VLAN interface”
■ “Naming the Current VLAN”
■ “Shutting down/Bringing up a VLAN Interface”
■ “Configuring Port-Based VLAN”
Creating/Deleting a
VLAN
You can use the following commands to create/delete a VLAN. If the VLAN to be
created exists, the system will enter the VLAN view directly. Otherwise, the system
will create the VLAN first, and then enter the VLAN view.
Perform the following configuration in system view.
Tab le 34 Create/Delete a VLAN or VLANs
Operation Command
Create a VLAN and enter the VLAN view vlan vlan-id
Create VLANs in batch vlan vlan-id-list
Delete an VLAN or VLANs undo vlan { vlan-id [ to vlan-id ] | all }