CCNP Routing and Switching ROUTE 300-101 Official Cert Guide

The Impact of NAT/PAT

Although classless public IP address assignment does help extend the life of the IPv4 address space, NAT probably has a bigger positive impact, because it enables an enterprise to use such a small number of public addresses. NAT allows an enterprise to use private IP addresses for each host, plus a small number of public addresses. As packets pass through a device performing NAT—often a firewall, but it could be a router—the NAT function translates the IP address from the private address (called an inside local address by NAT) into a public address (called an inside global address).

Note

For the purposes of this book, the terms NAT, PAT, and NAT overload are used synonymously. There is no need to distinguish between static ...