Chapter 10 Network Address Translation (NAT)
Figure 99 NAT Application With IP Alias
10.1.5 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.
The following table summarizes these types.
Table 55 NAT Mapping Types
TYPE | IP MAPPING |
One-to-One | ILA1ÅÆ IGA1 |
| |
Many-to-One (SUA/PAT) | ILA1ÅÆ IGA1 |
| ILA2ÅÆ IGA1 |
| … |
| |
| 149 |
P-660HW-Tx v3 User’s Guide |
| |