Abstract: The network address translation technology is mainly used to realize the network addresses conversion between internal and external. The technology, a practical and essential skill of network engineering mastered by the computer students, can effectively save IP address space and realize the sharing and utilization of IP addresses,which is widely used in various enterprise campus network design project. However, the network address translation protocol research and analysis on the physics experiment equipment has such problems as difficult operation, unfavorable for students to observe and understand, which greatly hinders the improvement of the quality of network engineering practice teaching. In order to effectively solve the problem of the contradiction between the practical teaching of network engineering and the existing laboratory equipment conditions, the article first analyzes the working principle and classification of the Network address translation protocol. Then, the network scenario is designed on the enterprise network simulation platform for experimental simulation, and the details are given. Two kinds of simulation experiment design and realization process of network address translation protocol are presented. Finally, the experimental analysis shows that this method of experimental teaching under the virtual platform can better deepen students' understanding of the principles of the NAT protocol and mastery of practical skills, and provide a solution to the problem of contradiction between teaching needs and experimental equipment conditions.

Key words: network address translation protocol, static address translation, dynamic address translation, simulation experiment