Configuring vlans – Allied Telesis AT-S95 WEB User Manual
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Page 118
Allied Telesis
AT-S95 Management Software Web Browser Interface User’s Guide
Configuring VLANs
This section describes how to create and configure Virtual LANs (VLANs).
VLANs are logical subgroups within 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-aware devices. VLAN tagging attaches a 4-byte tag to frame headers. The VLAN tag indicates to
which VLAN the frames 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 AT-S95 Series device that you want to
manage.
•
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 Interface Settings
•