User`s guide

Chapter 9 Network Address Translation (NAT)

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Device keeps track of the original addresses and port numbers so incoming reply packets can have

their original values restored. The following figure illustrates this.

Figure 90 How NAT Works

9.6.4 NAT Application

The following figure illustrates a possible NAT application, where three inside LANs (logical LANs

using IP alias) behind the Device can communicate with three distinct WAN networks.

Figure 91 NAT Application With IP Alias

9.6.5 NAT Mapping Types

NAT supports five types of IP/port mapping. They are:

192.168.1.13

192.168.1.10

192.168.1.11

192.168.1.12

192.168.1.10

IGA1

Inside Local

IP Address

192.168.1.10

192.168.1.11

192.168.1.12

192.168.1.13

Inside Global

IP Address

IGA 1

IGA 2

IGA 3

IGA 4

NAT Table

WAN

LAN

Inside Local

Address (ILA)

Inside Global

Address (IGA)