Nat Application; Nat Mapping Types - ZyXEL Communications P-660H-61 User Manual

9.6.4 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 69 NAT Application With IP Alias

9.6.5 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.
• Many-to-Many No Overload: In Many-to-Many No Overload mode, the ZyXEL Device maps
each local IP address to a unique global IP address.
• Server: This type allows you to specify inside servers of different services behind the NAT to be
accessible to the outside world.
Port numbers do NOT change for One-to-One and Many-to-Many No Overload NAT mapping
types.
ADSL Router Series User's Guide
Chapter 9 Network Address Translation (NAT)
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