ZyXEL Communications P-660HN-TxA - Manual (Page 148)

Chapter 9 Network Address Translation (NAT)
P-660HN-TxA User’s Guide
148
9.6.4 NAT Application
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.
Figure 72 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 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.