User`s guide

Chapter 9 Network Address Translation (NAT)
ericom D1000 modem User’s Guide
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• One to One: In One-to-One mode, the Device maps one local IP address to one global IP
address.
• Many to One: In Many-to-One mode, the Device maps multiple local IP addresses to one global
IP address.
• Many to Many Overload: In Many-to-Many Overload mode, the 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 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.
Port numbers do NOT change for One-to-One and Many-to-Many No Overload NAT mapping
types.
The following table summarizes these types.
Table 48 NAT Mapping 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
ILA3 IGA1
ILA4 IGA2
…
Many-to-Many No Overload ILA1 IGA1
ILA2 IGA2
ILA3 IGA3
…
Server Server 1 IP IGA1
Server 2 IP IGA1
Server 3 IP IGA1