Nat; Chapter 11 Nat; Overview; What You Can Do In This Chapter - ZyXEL Communications NXC2500 User Manual

11.1 Overview

NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP address of a host in
a packet. For example, the source address of an outgoing packet, used within one network is
changed to a different IP address known within another network. Use Network Address Translation
(NAT) to make computers on a private network behind the NXC available outside the private
network. If the NXC has only one public IP address, you can make the computers in the private
network available by using ports to forward packets to the appropriate private IP address.
Suppose you want to assign ports 21-25 to one FTP, Telnet and SMTP server (A in the example),
port 80 to another (B in the example) and assign a default server IP address of 192.168.1.35 to a
third (C in the example). You assign the LAN IP addresses and the ISP assigns the WAN IP address.
The NAT network appears as a single host on the Internet.
Figure 76 Multiple Servers Behind NAT Example

11.1.1 What You Can Do in this Chapter

The NAT screens (see
their configuration details. You can also create new NAT rules and edit or delete existing ones.

11.2 NAT Summary

The NAT summary screen provides a summary of all NAT rules and their configuration. In addition,
this screen allows you to create new NAT rules and edit and delete existing NAT rules. To access this
screen, login to the Web Configurator and click Configuration > Network > NAT. The following
screen appears, providing a summary of the existing NAT rules.
C
Section 11.2 on page 151) display and manage the list of NAT rules and see
NXC Series User's Guide
151
HAPTER
11

NAT