Netopia 4000 Series, Software Manual

Page: 67 / 314

Multiple Network Address Translation 3-1
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Netopia Firmware Version 5.4 offers advanced Multiple Network Address Translation functionality.
You should read this chapter completely before attempting to configure any of the advanced NAT features.
This chapter covers the following topics:
■ Over view on page 3-1
■ MultiNAT Configuration on page 3-6
■ Easy Setup Profile configuration on page 3-6
■ Ser ver Lists and Dynamic NAT configuration on page 3-7
■ Adding Ser ver Lists on page 3-15
■ Binding Map Lists and Ser ver Lists on page 3-21
■ NAT Associations on page 3-25
■
IP Passthrough on page 3-27
■
MultiNAT Configuration Example on page 3-31
Overview
NAT (Network Address Translation) is a means of mapping one or more IP addresses and/or IP ser vice por ts
into different values.
This mapping ser ves two functions:
■
It allows the addresses of many computers on a LAN to be represented to the public Internet by only one or
a few addresses, saving you money.
■ It can be used as a security feature by obscuring the true addresses of impor tant machines from potential
hackers on the Internet.
To help you understand some of the concepts discussed here, it may be helpful to introduce some NAT
terminology.
The term mapping refers to rules that associate one or more private addresses on the Netopia Router’s LAN to
one or more public addresses on the Netopia Routers WAN inter face (typically the Internet).
The terms private and internal refer to addresses on the Netopia Router’s LAN. These addresses are
considered private because they are protected or obscured by NAT and cannot be directly accessed from the
WAN (or Internet) side of the Netopia Router unless specifically configured other wise.
The terms public and external refer to the WAN (or Internet) side of the Netopia Router.