ZyXEL Communications P-870HW-I ユーザーズマニュアル

P-870HW-I1 User’s Guide

Appendix D NAT

383

The following figure illustrates a possible NAT application, where three inside LANs (logical 
LANs using IP Alias) behind the ZyXEL Device can communicate with three distinct WAN 
networks. More examples follow at the end of this chapter.

Figure 265   NAT Application With IP Alias

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 (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 ZyXEL Device maps 

the multiple local IP addresses to shared global IP addresses.

• Many One-to-One: In Many-One-to-One 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.