Allied Telesis AT-S79 manual Port-based Vlan Overview, Vlan Name Vlan Identifier

Chapter 7: Virtual LANs

Port-based VLAN Overview

VLAN Name

VLAN Identifier

As explained in “VLAN Features” on page 72, a VLAN consists of a group of ports on one or more Ethernet switches that form an independent traffic domain. Traffic generated by the end nodes of a VLAN remains within the VLAN and does not cross over to the end nodes of other VLANs unless there is an interconnection device, such as a router or Layer 3 switch.

A port-based VLAN is a group of ports on a Gigabit Ethernet switch that form a logical Ethernet segment. Each port of a port-based VLAN can belong to only one VLAN at a time.

A port-based VLAN can have as many or as few ports as needed. The VLAN can consist of all the ports on an Ethernet switch, or just a few ports. A port-based VLAN also can span switches and consist of ports from multiple Ethernet switches.

Note

The AT-GS950/16 and AT-GS950/24 switches are preconfigured with one port-based VLAN, called the Default VLAN. All ports on the switch are members of this VLAN.

A port-based VLAN consists of the following parts:

ˆVLAN name

ˆVLAN Identifier

ˆUntagged ports

ˆPort VLAN Identifier

To create a port-based VLAN, you must give it a name. The name should reflect the function of the network devices that are be members of the VLAN. Examples include Sales, Production, and Engineering.

Every VLAN in a network must have a unique number assigned to it. This number is called the VLAN identifier (VID). This number uniquely identifies a VLAN in the switch and the network.

If a VLAN consists only of ports located on one physical switch in your network, you assign it a VID different from all other VLANs in your network.

If a VLAN spans multiple switches, then the VID for the VLAN on the different switches should be the same. The switches are then able to recognize and forward frames belonging to the same VLAN even though the VLAN spans multiple switches.

74 Section I: Using the Menus Interface