SMC Networks SMC7204BRA manual Configuring Network Address Translation, Overview of NAT

CONFIGURING NETWORK ADDRESS TRANSLATION

This section provides an overview of Network Address Translation (NAT) and instructions for modifying the default configuration on your device.

Overview of NAT

Network Address Translation is a method for disguising the private IP addresses you use on your LAN as the public IP address you use on the Internet. You can define NAT rules that specify exactly how and when to translate between public and private IP addresses.

Definition: A private IP address is created by a network administrator for use only on a LAN, whereas

a public IP address is purchased from the Internet Corporation for Assigned Names and Numbers (ICANN) for use on the Internet. Typically, your ISP provides a public IP address for your entire LAN, and you define the private addresses

for computers on your LAN.

In a typical NAT setup, your ISP provides you with a single public IP address to use for your entire network. Then, you assign each computer on your LAN a unique private IP address. (Or, you define a pool of private IP addresses for dynamic assignment to your computers, as described in Configuring Dynamic Host Configuration Protocol.) On the ADSL Barricade, you set up a NAT rule to specify that whenever one of your computers communicates with

the Internet, (that is, it sends and receives IP data packets) its private IP address - which is referenced in each packet - will be replaced by the LAN's public IP address.

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