Before exploring the details of
Network Address Translation (NAT)
operations, configuration,
and troubleshooting, it’s important to thoroughly understand what it is, the terminology associated
with it, its advantages and disadvantages, and the traffic types it supports. NAT is a protocol
that maps an inside IP address used in the local, or inside, network environment to the
outside network environment and vice versa. There are many reasons for using NAT in your
network environment. Some of the benefits you will receive from NAT include the following:
Enabling a private IP network to use unregistered IP addresses to access an outside network
such as the Internet
Providing the ability to reuse assigned IP addresses that are already in use on the Internet
Providing Internet connectivity in networks where there are not enough individual Internetregistered
IP addresses
Appropriately translating the addresses in two merged intranets such as two merged companies
Translating internal IP addresses assigned by old Internet service providers (ISPs) to a new
ISP’s newly assigned addresses without manually configuring the local network interfaces