PT-7728 User’s Manual
Featured Functions
3-40
Benefits of VLANs
The main benefit of VLANs is that they provide a network segmentation system that is far more
flexible than traditional networks. Using VLANs also provides you with three other benefits:
y
VLANs ease the relocation of devices on networks.
With traditional networks, network
administrators spend much of their time dealing with moves and changes. If users move to a
different subnetwork, the addresses of each host must be updated manually. With a VLAN
setup, if a host on VLAN
Marketing,
for example, is moved to a port in another part of the
network, and retains its original subnet membership, you only need to specify that the new
port is on VLAN
Marketin
g. You do not need to carry out any re-cabling.
y
VLANs provide extra security.
Devices within each VLAN can only communicate with
other devices on the same VLAN. If a device on VLAN
Marketing
nePT to communicate with
devices on VLAN
Financ
e, the traffic must pass through a routing device or Layer 3 switch.
y
VLANs help control traffic.
With traditional networks, congestion can be caused by
broadcast traffic that is directed to all network devices, regardless of whether or not they need
it. VLANs increase the efficiency of your network because each VLAN can be set up to
contain only those devices that need to communicate with each other.
VLANs and the PowerTrans
Your PT-7728 provides support for VLANs using IEEE Std 802.1Q-1998. This standard allows
traffic from multiple VLANs to be carried across one physical link. The IEEE Std 802.1Q-1998
standard allows each port on your PT-7728 to be placed as follows:
y
In a single VLAN defined on the PT-7728
y
In several VLANs simultaneously using 802.1Q tagging
The standard requires that you define the
802.1Q VLAN ID
about each VLAN on your PT-7728
before the switch can use it to forward traffic:
Managing a VLAN
A new or initialized PT-7728 contains a single VLAN—the Default VLAN. This VLAN has the
following definition:
y
VLAN Name
—Management VLAN
y
802.1Q VLAN ID
—1 (if tagging is required)
All the ports are initially placed in this VLAN, and it is the only VLAN that allows you to access
the management software of the PT-7728 over the network.
Communication Between VLANs
If devices connected to a VLAN need to communicate to devices on a different VLAN, a router or
Layer 3 switching device with connections to both VLANs needs to be installed. Communication
between VLANs can only take place if they are all connected to a routing or Layer 3 switching
device.
