NetComm NB712 manual Nat/Dmz

8.6 NAT/DMZ

NAT (Network Address Translation) is the translation of an Internet Protocol address (IP address) used within one network to a different IP address known within another network. One network is designated as the inside network and the other is the outside. Typically, a company maps its local inside network addresses to one or more global outside IP address and changes the global IP addresses of incoming packets back into local IP addresses. This ensures security since each outgoing or incoming request must go through a translation process that also offers the opportunity

to qualify or authenticate the request or match it to a previous request. NAT also conserves the number of global IP addresses that a company needs and lets the company use a single IP address for its communication in the Internet world.

DMZ (demilitarized zone) is a computer host or small network inserted as a “neutral zone” between a company private network and the outside public network. It prevents outside users from getting direct access to a server that has company private data.

In a typical DMZ configuration for an enterprise, a separate computer or host receives requests from users within the private network to access Web sites or other companies accessible on the public network. The DMZ host then initiates sessions for these requests to the public network. However, the DMZ host is not able to initiate a session back into the private network. It can only forward packets that have already been requested.

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