Allied Telesis AT-S82 - Manual (Page 44)

Chapter 6: VLANs
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VLAN Overview
This VLAN overview contains the following sections:
ˆ “VLAN Name,” next
ˆ “VLAN Identifier” on page 44
ˆ “VLAN Port Members” on page 44
ˆ “Incoming and Outgoing Tagged and Untagged Frames” on page 45
ˆ “Guidelines for Creating a VLAN” on page 46
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 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, the VID for the VLAN on the different
switches should be the same. Then the switches are 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 members of a VLAN. A
port can be specified as a member of one or more VLANs up to 255 which
is 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.