ZyXEL Communications Internet Security Gateway ZyWALL 2 Series - Manual (Page 126)

ZyWALL 2 Series User’s Guide
8-4 NAT
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), the 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.
Many One to One: In Many-One-to-One mode, the ZyWALL 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-One-to-
One NAT mapping types.
TABLE 8-2 NAT MAPPING TYPES
TYPE IP MAPPING SMT ABBREVIATION
One-to-One ILA1 IGA1 1-1
Many-to-One (SUA/PAT) ILA1 IGA1
ILA2 IGA1
…
M-1
Many-to-Many Overload ILA1 IGA1
ILA2 IGA2
ILA3 IGA1
ILA4 IGA2
…
M-M Ov
Many-One-to-One ILA1 IGA1
ILA2 IGA2
ILA3 IGA3
…
M-1-1
Server Server 1 IP IGA1
Server 2 IP IGA1
Server 3 IP IGA1
Server
The following table summarizes these types.
8.2 Using NAT
You must create a firewall rule in addition to setting up SUA/NAT, to allow traffic
from the WAN to be forwarded through the ZyWALL.