ZyXEL Communications ZyXEL ZyAIR 100 - Manual (Page 126)

ZyWALL 10~100 Series Internet Security Gateway
9-4 NAT
The following figure illustrates a possible NAT application, where three inside LANs (logical LANs using IP
Alias) behind the ZyWALL can communicate with three distinct WAN networks. More examples follow at
the end of this chapter.
Figure 9-2 NAT Application With IP Alias
9.1.5 NAT Mapping Types
NAT supports five types of IP/port mapping. They are:
One to One: In One-to-One mode, the ZyWALL maps one local IP address to one global IP
address.
Many to One: In Many-to-One mode, the ZyWALL maps multiple local IP addresses to one global
IP address. This is equivalent to SUA (i.e., PAT, port address translation), ZyXEL’s Single User
Account feature (the SUA Only option).
Many to Many Overload: In Many-to-Many Overload mode, the ZyWALL maps the multiple
local IP addresses to shared global IP addresses.