Allied Telesis AT-S63 - Manual (Page 592)

Chapter 24: Port-based and Tagged VLANs
592 Section VI: Virtual LANs
Port-based VLAN Overview
As explained in “VLAN Overview” on page 590, 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-9400 Series switch is preconfigured with one port-based
VLAN. All ports on the switch are members of this VLAN, called the
Default_VLAN.
The parts that make up a port-based VLAN are:
ˆ VLAN name
ˆ VLAN Identifier
ˆ Untagged ports
ˆ Port VLAN Identifier
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.
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.