Virtual LANs
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Overview of Port-based VLANs
Port-based VLANs are the simplest and most common form of a VLAN. In
a port-based VLAN configuration, each port of the switch is assigned to a
specific VLAN. For example, you can designate port 1, 2, and 3 as part of
the engineering VLAN and ports 5, 6, and 7 as part of the marketing
VLAN.
A port-based VLAN can have as many or as little ports as needed. The
VLAN can consist of all the ports on the AT-FS7016 or AT-FS7024 Smart
Switch, or just a few ports.
Ports in a port-based VLAN are referred to as “untagged ports” and the
frames received on the ports as “untagged frames”. The term
“untagged” is based on that fact that the frames received on a port will
not contain any information that indicates VLAN membership, and that
VLAN membership will be determined only by the port’s PVID.
Port VLAN
Identifier
Each port in a port-based VLAN must have a Port VLAN Identifier (PVID).
The switch associates a frame to a port-based VLAN by the PVID
assigned to the port on which the frame is received and forwards the
frame only to those ports with the same PVID. Consequently, all the
ports of a port-based VLAN must had the same PVID.
Some switches and switch management programs require that you
assign the PVID value for each port manually. However, the AT-S67 and
AT-S68 management software performs this task automatically. The
software automatically assigns a PVID to a port, making it identical to the
VID of the VLAN to which the port is a member.
Special VLAN
Configuration
Feature
The AT-FS7016 and AT-FS7024 Smart Switches provide an enhanced
port-based VLAN feature, which allows a port to be a member of more
than one port-based VLAN. This feature allows you to configure a single
uplink port (for example, to a router) on every VLAN for the purpose of
connecting to a remote location without compromising the basic
security features of a multiple VLAN configuration.
An example of this implementation would be a hotel network which
requires all rooms to be isolated from each other but allow all rooms to
access the internet through a common router.
