VSG-1200 User’s Guide
Chapter 5 NAT Pool
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H A P T E R
5
NAT Pool
This chapter shows how to configure Network Address Translation (NAT) on the WAN for
VPN packets.
5.1 NAT Introduction
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.
5.1.1 NAT Definitions
Inside/outside denotes where a host is located relative to the VSG, 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 11
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 VSG-1200
Page 1: ...VSG 1200 Vantage Service Gateway User s Guide Version 1 08 1 2006 ...
Page 8: ...VSG 1200 User s Guide 8 Customer Support ...
Page 22: ...VSG 1200 User s Guide 22 List of Figures ...
Page 26: ...VSG 1200 User s Guide 26 List of Tables ...
Page 40: ...VSG 1200 User s Guide 40 Chapter 2 Hardware Installation and Connection ...
Page 45: ...VSG 1200 User s Guide Chapter 3 The Web Configurator 45 Figure 13 System Setting System ...
Page 52: ...VSG 1200 User s Guide 52 Chapter 3 The Web Configurator ...
Page 64: ...VSG 1200 User s Guide 64 Chapter 4 LAN WAN and Server Setup ...
Page 74: ...VSG 1200 User s Guide 74 Chapter 6 Authentication Figure 29 System Setting Authentication ...
Page 102: ...VSG 1200 User s Guide 102 Chapter 9 Dynamic Subscriber Accounts ...
Page 128: ...VSG 1200 User s Guide 128 Chapter 13 Subscriber Information Window ...
Page 136: ...VSG 1200 User s Guide 136 Chapter 14 Account Printout ...
Page 140: ...VSG 1200 User s Guide 140 Chapter 15 User Agreement Page ...
Page 144: ...VSG 1200 User s Guide 144 Chapter 16 Bandwidth Management ...
Page 158: ...VSG 1200 User s Guide 158 Chapter 19 LAN Devices ...
Page 162: ...VSG 1200 User s Guide 162 Chapter 20 Static Route ...
Page 170: ...VSG 1200 User s Guide 170 Chapter 21 Syslog and Session Trace ...
Page 174: ...VSG 1200 User s Guide 174 Chapter 22 SNMP ...
Page 198: ...VSG 1200 User s Guide 198 Chapter 25 Secure Socket Layer ...
Page 206: ...VSG 1200 User s Guide 206 Chapter 26 The SMT ...
Page 214: ...VSG 1200 User s Guide 214 Chapter 27 LAN and WAN Setup Using the SMT ...
Page 226: ...VSG 1200 User s Guide 226 Chapter 28 Configuration and Firmware Maintenance ...
Page 236: ...VSG 1200 User s Guide 236 Appendix B IP Address Assignment Conflicts ...
Page 238: ...VSG 1200 User s Guide 238 Appendix C Subscriber Login ...
Page 242: ...VSG 1200 User s Guide 242 Appendix D Vendor Specific Attributes ...
Page 252: ...VSG 1200 User s Guide 252 Appendix F Cable Types and Cable Pin Assignments ...
Page 264: ...VSG 1200 User s Guide 264 Appendix G Setting up Your Computer s IP Address ...
Page 272: ...VSG 1200 User s Guide 272 Appendix H IP Subnetting ...