Understanding the Network: A Practical Guide to Internetworking

Network Address Translation

Internet access today (from both the home and office) is almost as commonplace as the telephone. With the demand for access to the Internet today almost doubling in size on a yearly basis, IPv4 address space is getting tight. Additionally, before Internet access became widespread. The TCP/IP protocol was widely used on many private enterprise networks. Since these networks were private (no Internet access), many administrators used "illegal" IP address ranges. These "illegal" address ranges, were IP addresses "assigned" to companies, by IANA for use on the public Internet. Other network administrators use the IANA provided "unregistered" IP address spaces to address their networks. Of course, in either instance, ...