Installation guide

Product Description
38
Tagged and
Port-based
VLANs
A VLAN is a group of end nodes that form an independent subnetwork.
Each VLAN constitutes a separate broadcast domain, where the frames
of a VLAN are not allowed to cross the VLAN boundary.
VLANs can be extremely useful in improving network performance and
increasing network security. You can create VLANs to group the
workstations, servers, and other networking equipment connected to
your switches into logical workgroups. These VLAN groupings can be
based on similar data needs or security requirements. When networking
devices, such as workstations and servers, are grouped into a VLAN, data
is exchanged between only those members of the group.
Other advantages of VLANs include:
# You can group workstations logically or functionally, regardless of
their physical location on the network.
# You can change VLAN memberships anytime by software
configuration without moving the workstations physically or
having to move cables from one port to another on the switch.
# With VLAN tagging, network servers or other network resources
can be shared among several VLANs without loss of data isolation
or security.
# A VLAN can consist of ports limited to a single switch or ports from
multiple switches. This allows you to group together network
devices that, though physically separated by large distances, will
function as if they are a part of the same physical LAN.
The AT-8000 Series Fast Ethernet Switches support two types of VLANs:
# Port-based VLANs
# Tagged VLANs
The Fast Ethernet switches come configured with one port-based VLAN,
called the Default_VLAN. All ports on the switch are members of this
VLAN.
Basic VLAN
Mode
These Fast Ethernet switches support a special VLAN configuration
referred to as Basic VLAN Mode. When the Basic VLAN Mode is activated,
the switch forwards frames based only on MAC addresses. All VLAN
information, including port VLAN identifiers (PVIDs) and VLAN tags, is
ignored. Tagged frames are analyzed only for priority level.