5.2.1.4 NAT Mapping Types
NAT supports five types of IP/port mapping. They are:
1. One-to-One: In One-to-One mode, the DSL-2120/2120W maps one local IP address to
one global IP address.
2. Many-to-One: In Many-to-One mode, the DSL-2120/2120W maps multiple local IP
addresses to one global IP address.
3. Many-to-Many Overload: In Many-to-Many Overload mode, the DSL-2120/2120W
maps multiple local IP addresses to shared global IP addresses.
4. Many-to-Many No Overload: In Many-to-Many No Overload mode, the
DSL-2120/2120W 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
ILA2 IGA2
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Revision: V1.0
Apr. 23, 2008