Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

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Wireless Local Area Networks (WLANs)
VLAN Assignment
VLAN Assignment
The instructions for configuring a WLAN include the basic mechanics for
assigning all traffic from a WLAN to a VLAN.
This section will explain in more depth when and why you would assign one
WLAN to one VLAN and another WLAN to another VLAN. You will also learn
about the ability of the Wireless Edge Services xl Module to assign individual
wireless users to VLANs—an ability that provides a high degree of flexibility
and control at the edge of the network.
To understand the importance of the VLAN assignment, consider role of the
Wireless Edge Services xl Module as the guard between the wireless and wired
portions of your network. RPs encapsulate wireless traffic with Ethernet
headers so wireless users can access the wired network, but the module
controls this traffic so that wireless users receive the appropriate network
access.
In a traditional Ethernet network, one of the primary ways in which adminis-
trators control network rights is by assigning users to various subnetworks,
or VLANs. Traditionally, administrators used hardware-based rules to enforce
these assignments: they plugged a user’s workstation into a switch port
configured to carry traffic on the appropriate VLAN. However, you cannot
control mobile users in a wireless network in this way, because wireless users
do not connect through a set port. Instead:
■ Users may connect through different ports at different times.
■ Traffic from many different users may arrive on the same port.
When you configure VLAN assignment on a Wireless Edge Services xl Module,
you enable the module to take over, for wireless stations, the role of assigning
users to the correct VLANs. In other words, you establish the foundation for
control over mobile users’ network rights. The module acts as an intelligent
door to your network, opening on the correct subnetwork for each wireless
user.
You have a choice about how to treat the VLANs to which the module assigns
wireless traffic. If you want your wired infrastructure devices to handle this
traffic, make sure that on the wireless-services enabled switch you tag the
module’s internal uplink port for these VLANs. If you want the Wireless Edge
Services xl Module to route the wireless traffic into VLANs used on the wired
network, you should not tag the internal uplink port for the VLANs for wireless