WESM zl Management and Configuration Guide WT.01.28 and greater

8-3
Configuring Network Address Translation (NAT)
Overview
Figure 8-1. Dividing Interfaces into Inside and Outside Interfaces
The Wireless Edge Services zl Module always performs NAT on traffic as the traffic
arrives on an interface. Because the module can apply NAT to both inside and outside
interfaces, it can perform NAT in both directions.
Note When the Wireless Edge Services zl Module maps wireless traffic to a VLAN, that
traffic is considered to have arrived on the VLAN interface.
Local and Global Addresses
In addition to identifying inside and outside networks, the Wireless Edge Services zl
Module distinguishes between an IP address as it appears before and after translation.
The Web browser interface and the command line interface (CLI) use two terms to
make this distinction:
■ local IP address—the IP address as it appears before translation
■ global IP address—the IP address as it appears after translation
As mentioned earlier, the Wireless Edge Services zl Module translates the IP address
in a packet’s IP header. Depending on how you implement NAT, the module can
translate a packet’s source IP address or its destination IP address.