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

8-9
Configuring Network Address Translation (NAT)
Overview
Configure destination NAT to allow wireless users to send traffic toward a
server’s publicly known address. The Wireless Edge Services xl Module trans-
lates the traffic’s destination address to the correct local address. When the
server replies, the module automatically translates the source address back
to the address to which the traffic was originally destined, and the private
address remains concealed.
For example, your company may have a Web server or an FTP server, which
is housed on your internal LAN. To access this server, wireless users enter a
URL, which is resolved through a Domain Name System (DNS) server to a
public IP address. When your Wireless Edge Services xl Module receives a
packet destined to this address, it translates the destination IP address and
forwards the packet toward the correct internal device.
For example, in Figure 8-4, a Web server on the internal LAN has an IP address
of 192.168.1.10. However, the IP address to which wireless stations send traffic
is 10.1.1.1. When the ProCurve Wireless Edge Services xl Module receives
packets with the destination address of 10.1.1.1, it translates the destination
address to the private IP address of the Web server: 192.168.1.10. The source
IP address is not affected. (See Figure 8-4.) Therefore, you must ensure that
devices in the wired network can route traffic back to the subnetwork used
in the wireless network.
Figure 8-4. Outside Destination NAT