The concepts of private and public IP addressing tie in directly to the proper configuration of NAT. The purpose of NAT is to translate between private networks and the public Internet. Many users with NAT enabled see no difference in the connection and surf as if they have a public IP address. It is your job as an administrator to ensure that NAT operates seamlessly and to troubleshoot any issues for these users. You can further review the topics from today on pages 39–68 and 255–292 of CCNA Flash Cards and Exam Practice Pack (CCENT Exam 640-822 and CCNA Exams 640-816 and 640-802), Third Edition.