P-662H/HW-D Series User’s Guide
Chapter 9 Network Address Translation (NAT) Screens
157
C
H A P T E R
9
Network Address Translation
(NAT) Screens
This chapter discusses how to configure NAT on the ZyXEL Device.
9.1 NAT 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 to a different IP address known within another network.
9.1.1 NAT Definitions
Inside/outside denotes where a host is located relative to the ZyXEL Device, for example, the
computers of your subscribers are the inside hosts, while the web servers on the Internet are
the outside hosts.
Global/local denotes the IP address of a host in a packet as the packet traverses a router, for
example, the local address refers to the IP address of a host when the packet is in the local
network, while the global address refers to the IP address of the host when the same packet is
traveling in the WAN side.
Note that inside/outside refers to the location of a host, while global/local refers to the IP
address of a host used in a packet. Thus, an inside local address (ILA) is the IP address of an
inside host in a packet when the packet is still in the local network, while an inside global
address (IGA) is the IP address of the same inside host when the packet is on the WAN side.
The following table summarizes this information.
NAT never changes the IP address (either local or global) of an outside host.
Table 52
NAT Definitions
ITEM
DESCRIPTION
Inside
This refers to the host on the LAN.
Outside
This refers to the host on the WAN.
Local
This refers to the packet address (source or destination) as the packet travels on the
LAN.
Global
This refers to the packet address (source or destination) as the packet travels on the
WAN.
Summary of Contents for 802.11g ADSL 2+ 4-Port Security Gateway HW-D Series
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Page 10: ...P 662H HW D Series User s Guide 10 Customer Support ...
Page 24: ...P 662H HW D Series User s Guide 24 Table of Contents ...
Page 32: ...P 662H HW D Series User s Guide 32 List of Figures ...
Page 38: ...P 662H HW D Series User s Guide 38 List of Tables ...
Page 64: ...P 662H HW D Series User s Guide 64 Chapter 2 Introducing the Web Configurator ...
Page 84: ...P 662H HW D Series User s Guide 84 Chapter 4 Bandwidth Management Wizard ...
Page 108: ...P 662H HW D Series User s Guide 108 Chapter 5 WAN Setup ...
Page 122: ...P 662H HW D Series User s Guide 122 Chapter 6 LAN Setup ...
Page 156: ...P 662H HW D Series User s Guide 156 Chapter 8 DMZ ...
Page 202: ...P 662H HW D Series User s Guide 202 Chapter 11 Firewall Configuration ...
Page 210: ...P 662H HW D Series User s Guide 210 Chapter 12 Anti Virus Packet Scan ...
Page 214: ...P 662H HW D Series User s Guide 214 Chapter 13 Content Filtering ...
Page 232: ...P 662H HW D Series User s Guide 232 Chapter 14 Content Access Control ...
Page 238: ...P 662H HW D Series User s Guide 238 Chapter 15 Introduction to IPSec ...
Page 273: ...P 662H HW D Series User s Guide Chapter 17 Certificates 273 Figure 144 My Certificate Details ...
Page 292: ...P 662H HW D Series User s Guide 292 Chapter 18 Static Route ...
Page 304: ...P 662H HW D Series User s Guide 304 Chapter 19 Bandwidth Management ...
Page 308: ...P 662H HW D Series User s Guide 308 Chapter 20 Dynamic DNS Setup ...
Page 332: ...P 662H HW D Series User s Guide 332 Chapter 22 Universal Plug and Play UPnP ...
Page 338: ...P 662H HW D Series User s Guide 338 Chapter 23 System ...
Page 344: ...P 662H HW D Series User s Guide 344 Chapter 24 Logs ...
Page 350: ...P 662H HW D Series User s Guide 350 Chapter 25 Tools ...
Page 364: ...P 662H HW D Series User s Guide 364 Chapter 27 Troubleshooting ...
Page 368: ...P 662H HW D Series User s Guide 368 Product Specifications ...
Page 372: ...P 662H HW D Series User s Guide 372 Appendix C Wall mounting Instructions ...
Page 408: ...P 662H HW D Series User s Guide 408 Appendix F Wireless LANs ...
Page 420: ...P 662H HW D Series User s Guide 420 Appendix H Command Interpreter ...
Page 436: ...P 662H HW D Series User s Guide 436 Appendix L NetBIOS Filter Commands ...
Page 462: ...P 662H HW D Series User s Guide 462 Appendix M Internal SPTGEN ...
Page 484: ...P 662H HW D Series User s Guide 484 Appendix P Triangle Route ...