Page 74
Allied Telesis AT-8000S Switch
Web Browser Interface User’s Guide
Configuring VLANs
This section describes how to create and configure Virtual LANs (VLANs).
VLANs are logical subgroups with a Local Area Network (LAN) which combine user stations and network devices
into a single unit, regardless of the physical LAN segment to which they are attached. VLANs allow network traffic
to flow more efficiently within subgroups. VLANs use software to reduce the amount of time it takes for network
changes, additions, and moves to be implemented.
VLANs have no minimum number of ports, and can be created per unit, per device, or through any other logical
connection combination, since they are software-based and not defined by physical attributes.
VLANs function at Layer 2. Since VLANs isolate traffic within the VLAN, a Layer 3 router working at a protocol
level is required to allow traffic flow between VLANs. Layer 3 routers identify segments and coordinate with
VLANs. VLANs are Broadcast and Multicast domains. Broadcast and Multicast traffic is transmitted only in the
VLAN in which the traffic is generated. VLAN tagging provides a method of transferring VLAN information between
VLAN groups. VLAN tagging attaches a 4-byte tag to packet headers. The VLAN tag indicates to which VLAN the
packets belong. VLAN tags are attached to the VLAN by either the end station or the network device. VLAN tags
also contain VLAN network priority information.
Combining VLANs and Generic Attribute Registration Protocol (GARP) allows network managers to define
network nodes into Broadcast domains.
When configuring VLANs ensure the following:
•When using this feature, the management VLAN must exist on each 8000S Series device that you want to
manage.
•All of the devices in an enhanced stack must use the same management VLAN. Consequently, you must use
the following procedure to specify the management VLAN on each slave and master device of an enhanced
stack.
•The uplink and downlink ports on each device that are functioning as the tagged or untagged data links
between the devices must be either tagged or untagged members of the management VLAN.
•The port on the device to which the management station is connected must be a member of the management
VLAN.
This section contains the following topics:
•Defining VLAN Properties
•Defining VLAN Interface Settings
•Defining GVRP