ZyXEL Communications ZYWALL10 - Manual (Page 79)

ZyWALL 10 Internet Security Gateway
NAT 6-3
6.1.4 NAT Mapping Types
NAT supports five types of IP/port mapping. They are:
1. One to One: In One-to-One mode, the ZyWALL maps one local IP address to one global IP address.
2. 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 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 ZyWALL maps the multiple local IP
addresses to shared global IP addresses.
4. Many to Many No Overload: In Many-to-Many No Overload mode, the ZyWALL maps the each local
IP addresses to unique global IP addresses.
5. 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.
The following table summarizes these types.
Table 6-2 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-to-Many No Overload ILA1 !" IGA1
ILA2 !" IGA2
ILA3 !" IGA3
…
M:M No Ov