WESM zl Management and Configuration Guide WT.01.28 and greater

8-6
Configuring Network Address Translation (NAT)
Overview
Dynamic NAT for Wired Traffic
You can configure dynamic NAT for traffic bound from the wired network to the
wireless network. In this case, the Wireless Edge Services zl Module translates wired
devices’ IP addresses to one of the module’s own IP addresses.
You might use dynamic NAT on wired traffic when your wireless network receives
a great deal of public traffic. You can then conceal the IP addresses of devices in your
private network from the wireless users. (See Figure 8-3.)
Figure 8-3. Dynamic Source NAT
Again, whether you apply dynamic NAT to inside or outside traffic depends on how
you have defined interfaces. In this example, you have defined the VLAN used in
the wired network as an outside interface, so you configure outside dynamic NAT.
If you want to allow wireless users to access internal servers, you must configure
destination NAT to translate the publicly known IP address back to the servers’
internal addresses. (See “Static NAT on Destination Addresses” on page 8-7.)
In fact, instead of configuring dynamic source NAT to conceal private addresses, you
might want to configure only destination NAT. The Wireless Edge Services zl Module
automatically performs source NAT on the traffic returning from the server.