Allied Telesis AT-S82 - Manual (Page 40)

Chapter 5: VLANs
40
VLAN Overview
This VLAN overview contains the following sections:
ˆ “VLAN Name,” next
ˆ “VLAN Identifier” on page 40
ˆ “VLAN Port Members” on page 40
ˆ “Incoming and Outgoing Tagged and Untagged Frames” on page 41
ˆ “Guidelines for Creating a VLAN” on page 42
VLAN Name
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.
VLAN Identifier
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. The factory default VID is 1 for all
ports.
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.
For example, if you had a VLAN titled Marketing that spanned three
AT-GS950/8 switches, you would assign the Marketing VLAN on each
switch the same VID.
VLAN Port
Members
You need to specify which ports on the switch are to be members of a
VLAN. A port can be specified as a member of one or more VLANs up to
255, the maximum number of VLANs supported by the switch. The factory
default VID is 1. Therefore, each port is initially configured to be a member
of VLAN 1, which is known as the default VLAN.
Note
The switch is preconfigured with the Default VLAN only. All ports on
the switch are initially members of the Default VLAN.
If a port is assigned to be a new member of a VLAN, its membership can
be defined as either tagged or untagged.