The advantage of using private IP addresses is that it allows an organization to use private addressing in a
network, and use the Internet at the same time, by implementing Network Address Translation (NAT).
NAT is defined in RFC 1631 and allows a host that does not have a valid registered IP address to
communicate with other hosts through the Internet. Essentially, NAT allows hosts that use private addresses
or addresses assigned to another organization, i.e. addresses that are not Internet-ready, to continue to be
used and still allows communication with hosts across the Internet. NAT accomplishes this by using a valid
registered IP address to represent the private address to the rest of the Internet. The NAT function changes
the private IP addresses to publicly registered IP addresses inside each IP packet that is transmitted to a host
on the Internet.