Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.01.03 or 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. You will also learn about
the Wireless Edge Services xl Module’s ability 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 the Wireless
Edge Services xl Module’s role as the guard between the wireless and wired
portions of your network. RPs transform wireless traffic into Ethernet traffic
so that wireless users can access your network, but the Wireless Edge Services
xl Module controls this traffic so that wireless users receive the appropriate
network access.
In a traditional Ethernet network, one of the primary ways that administrators
control network rights is by assigning users to various subnets, 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:
■ 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 subnet for each wireless user.
The Wireless Edge Services xl Module determines the VLAN to which to assign
traffic based on one of two criteria:
■ the wireless station’s WLAN
■ the wireless user’s identity
You configure WLAN-based VLAN assignment manually. (See “VLAN” on
page 3-33)