Nat Application; Nat Mapping Types - ZyXEL Communications eircom D1000 User Manual

Chapter 9 Network Address Translation (NAT)
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
LAN
192.168.1.12
192.168.1.11

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:
132
192.168.1.13
SA
192.168.1.10
Inside Local
Address (ILA)
192.168.1.10
NAT Table
Inside Local Inside Global
IP Address
IP Address
192.168.1.10
IGA 1
192.168.1.11
IGA 2
192.168.1.12
IGA 3
192.168.1.13 IGA 4
SA
IGA1
Inside Global
Address (IGA)
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WAN