WESM zl Management and Configuration Guide WT.01.03 and greater

1-16
Introduction
ProCurve Wireless Edge Services zl Module
2. The module applies controls to the traffic, if any are configured. The
controls can include:
• a user-based ACL or rate-limit assigned by ProCurve IDM
• a manual IP or MAC extended ACL applied to the uplink port
• a manual IP ACL applied to the VLAN interface
3. The module creates the correct 802.11 frame, drawing on information
specified in the association with the destination station. The module also
encrypts the frame, if necessary.
4. The module encapsulates the 802.11 frame. The encapsulation header
includes a tag for the Radio Port VLAN specified for the radio to which
the destination station has associated.
5. The module forwards the traffic toward its destination on its downlink port.
Layer 2 and Layer 3 Operation
You have been introduced to how the Wireless Edge Services zl Module
receives, processes, and forwards traffic. You can now become better
acquainted with specific operations that the module applies to traffic. For
example, the module might apply an ACL to the traffic or perform NAT on it.
To understand when the module performs specific functions, you must first
understand how the module (and adopted RPs) operate at Layer 2 and Layer 3.
The Wireless Edge Services zl Module’s downlink port and associated RPs
function as Layer 2 devices. The Wireless Edge Services zl Module itself, as
well as its uplink port, can operate at Layer 3 as well as Layer 2.
RP Operations
RPs typically function at Layer 2 and do not have IP addresses; the Wireless
Edge Services zl Module manages all communications with them.
In some configurations, however, an RP can receive an IP address and operate
at Layer 3. When an RP cannot reach a Wireless Edge Services zl Module at
Layer 2, it obtains a dynamic IP address and learns the module’s IP address.
In this case, the RP communicates with the module at Layer 3. See “Commu-
nications Between an RP and the Wireless Edge Services zl Module: Layer 2
and Layer 3 Adoption” on page 1-68.