User`s guide

Chapter 11 Network Address Translation (NAT) Screens
P-2602HWUDL-D User’s Guide
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11.1.4 NAT Application
The following figure illustrates a possible NAT application, where three inside LANs (logical
LANs using IP alias) behind the ZyXEL Device can communicate with three distinct WAN
networks.
Figure 127 NAT Application With IP Alias
11.1.5 NAT Mapping Types
NAT supports five types of IP/port mapping. They are:
• One to One: In One-to-One mode, the ZyXEL Device maps one local IP address to one
global IP address.
• Many to One: In Many-to-One mode, the ZyXEL Device maps multiple local IP
addresses to one global IP address. This is equivalent to SUA (for instance, PAT, port
address translation), ZyXEL’s Single User Account feature that previous ZyXEL routers
supported (the SUA Only option in today’s routers).
• Many to Many Overload: In Many-to-Many Overload mode, the ZyXEL Device maps
the multiple local IP addresses to shared global IP addresses.
Internet
Corporation B
NAT Server
192.168.3.1
LAN3: 192.168.3.X
Network Server
“R&D”=192.168.3.1
WAN Addresses: LAN Addresses: (Default IPs)
IGA 1 ---------------> 192.168.1.1
IGA 2 ---------------> 192.168.2.1
IGA 3 ---------------> 192.168.3.1
NAT Server
192.168.2.1
LAN2: 192.168.2.X
Network Server
“Sales”=192.168.2.1
Server in
R&D Network
=IP3 (IGA 3)
NAT Server
192.168.1.1
LAN2: 192.168.1.X
Network Server
“Admin=192.168.1.1
Corporation A
Server in
Sales Network
=IP2 (IGA 2)
Server in
Admin Network
=IP1 (IGA 1)