WESM zl Management and Configuration Guide WT.01.XX and greater

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Introduction
ProCurve Wireless Edge Services zl Module
Wireless Edge Services zl Module Operations
The downlink port does not have an IP address; it is tagged for the Radio Port
VLAN, and the module does not require an IP address on this VLAN.
The Wireless Edge Services zl Module operates at Layer 2 on its downlink port.
On the downlink port, the module receives encapsulated 802.11 frames. It
decapsulates and processes these frames and then bridges them to an Ether-
net subnetwork (VLAN). When transmitting traffic back to wireless stations,
the module also acts at Layer 2, forwarding traffic based on the associations
to those stations.
After the module bridges a frame to a VLAN interface, the module can handle
the inner packet at Layer 3. Note that this VLAN interface may or may not be
tagged on the uplink port.
The module can also act at Layer 3 on traffic received on its uplink port, which
can be tagged for one or several VLANs.
Note Never tag the internal uplink and the downlink ports for the same VLAN.
In total, the Wireless Edge Services zl Module can support up to eight VLAN
interfaces with IP addresses and Layer 3 functionality. (The module can tag
traffic for these VLANs or for other VLANs that operate at Layer 2 only; in this
guide, a VLAN interface refers only to those VLANs that have been configured
with IP addresses.)
Whether traffic arrives on a VLAN interface on the uplink port or is bridged
to the VLAN from a WLAN, the module can handle the traffic as follows:
■ respond to or relay DHCP requests
■ apply IP ACLs to packets
■ perform NAT on packets
■ filter packets using the internal firewall
■ route packets to their destinations
The following section helps you to consider when your environment requires
your Wireless Edge Services zl Module to provide these services. The sections
that follow provide more information about each particular capability.