Abstract: With the rapid development of information technology, network security has become the focus of attention of governments. In order to combat the growing network attacks on critical infrastructures in the field of the government, national defense and industrial control, many countries in the world to carry out technology research and application of network range. This paper describes the definition and characteristics of network range, introduces the construction contents of the network range and the present situation of the United States and other developed countries, puts forward some enlightenments to our country network range construction.

Key words: network range, situation in foreign countries, enlightenment