ZyXEL Communications P-660HN-F1A, User Manual

Page: 186 / 430

Chapter 9 Network Address Translation (NAT)
P-660HN-F1A User’s Guide
186
9.6.4 NAT Application
The following figure illustrates a possible NAT application, where three inside LANs
(logical LANs using IP alias) behind the P-660HN-F1A can communicate with three
distinct WAN networks.
Figure 73 NAT Application With IP Alias
9.6.5 NAT Mapping Types
NAT supports five types of IP/port mapping. They are:
• One to One: In One-to-One mode, the P-660HN-F1A maps one local IP address
to one global IP address.
• Many to One: In Many-to-One mode, the P-660HN-F1A 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 P-660HN-F1A
maps the multiple local IP addresses to shared global IP addresses.
• Many-to-Many No Overload: In Many-to-Many No Overload mode, the P-
660HN-F1A 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.