Chapter 14 Nat; Overview; What You Can Do In This Chapter - ZyXEL Communications NXC5200 User Manual

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H A P T E R

14.1 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 89 Multiple Servers Behind NAT Example

14.1.1 What You Can Do in this Chapter

The NAT screens (see
NAT rules and see their configuration details. You can also create new NAT rules
and edit or delete existing ones.
NXC5200 User's Guide
Section 14.2 on page 218) display and manage the list of
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NAT
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