ZyXEL Communications P-2900-4HB User Manual

Page of 126
 Chapter 6 Network Address Translation (NAT) Screens
P-2900-4HB User’s Guide
65
6.3.4  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.
• 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 NAT mapping type. 
The following table summarizes these types.
Table 14   NAT Mapping Types
TYPE
IP MAPPING
One-to-One
ILA1ÅÆ IGA1
Many-to-One
ILA1ÅÆ IGA1
ILA2ÅÆ IGA1
Server
Server 1 IPÅÆ IGA1
Server 2 IPÅÆ IGA1
Server 3 IPÅÆ IGA1