ZyXEL Communications Prestige 645R-A Series, User Manual, Page: 59 / 251

Prestige 645R-A Series User’s Guide
NAT 6-3
6.1.4 NAT Application
The following figure illustrates a possible NAT application, where three inside LANs (logical LANs using IP
Alias) behind the Prestige can communicate with three distinct WAN networks. More examples follow at the
end of this chapter.
Figure 6-2 NAT Application With IP Alias
6.1.5 NAT Mapping Types
NAT supports five types of IP/port mapping. They are:
1. One to One : In One-to-One mode, the Prestige maps one local IP address to one global IP address.
2. Many to One : In Many-to-One mode, the Prestige 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).
3. Many to Many Overload : In Many-to-Many Overload mode, the Prestige maps the multiple local IP
addresses to shared global IP addresses.