Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

8-4
Configuring Network Address Translation (NAT)
Overview
Figure 8-1. Dividing Interfaces into Inside and Outside Interfaces
The Wireless Edge Services xl 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 xl 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 xl 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 xl 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.