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7.1.4 NAT Application
The following figure illustrates a possible NAT application, where three inside LANs (logical
LANs using IP Alias) behind the BIPAC-5100/5100W can communicate with three distinct
WAN networks. More examples follow at the end of this chapter.
7.1.5 NAT Mapping Types
NAT supports five types of IP/port mapping. They are:
1. One to One: In One-to-One mode, the BIPAC-5100/5100W maps one local IP address to
one global IP address.
2. Many to One: In Many-to-One mode, the BIPAC-5100/5100W maps multiple local IP
addresses to one global IP address. This is equivalent to SUA (for instance, PAT, port
address translation), Billion’s Single User Account feature that previous Billion routers
supported (the SUA Only option in today’s routers).
3. Many to Many Overload: In Many-to-Many Overload mode, the BIPAC-5100/5100W maps
the multiple local IP addresses to shared global IP addresses.
4. Many-to-Many No Overload: In Many-to-Many No Overload mode, the BIPAC-5100/5100W
maps each local IP address to a unique global IP address.
5. Server: This type allows you to specify inside servers of different services behind the NAT to
be accessible to the outside world.
The following table summarizes these types.
TYPE
IP MAPPING
One-to-One
ILA1
IGA1
Many-to-One (SUA/PAT)
ILA1
IGA1
ILA2
IGA1
…
Many-to-Many Overload
ILA1
IGA1
