A national intranet is an Internet protocol-based walled garden network maintained by a nation state as a national substitute for the global Internet, with the aim of controlling and monitoring the communications of its inhabitants, as well as restricting their access to outside media. Other names have been used, such as the use of the term "halal internet" in Islamic countries.
North Korea's Kwangmyong network, dating back to 2000, is the best-known of this type of network. Cuba and Myanmar also use a similar network system that is separated from the rest of the Internet.
In April 2011, a senior Iranian official, Ali Agha-Mohammadi announced government plans to launch its own "halal internet", which would conform to Islamic values and provide "appropriate" services. Creating such a network, similar to the North Korean example, would prevent unwanted information from outside Iran getting into the closed system. The Iranian walled garden would have its own localized email service and search engine.
A primary insight flows from our research and it pertains to the stability of China’s internet: the internet in China is a walled garden in terms of structure yet at the same time dependent upon Western Europe and the United States for foreign connectivity. Put plainly, in terms of resilience, China could effectively withdraw from the global public internet and maintain domestic connectivity (essentially having an intranet). This means the rest of the world could be restricted from connecting into China, and vice versa for external connections for Chinese businesses/users. 
List of National Intranets
- Christopher Rhoads and Farnaz Fassihi (May 28, 2011). "Iran Vows to Unplug Internet". Wall Street Journal. Retrieved 2012-09-24.
- "Iran clamps down on Internet use", Saeed Kamali Dehghan, The Guardian, 5 January 2012
- Ryan Paul (April 10, 2012). "Iran moving ahead with plans for national intranet". Ars Technica. Retrieved 2012-09-24.
- Dave Allen (July 19, 2019). "Analysis by Oracle Internet Intelligence Highlights China's Unique Approach to Connecting to the Global Internet". Oracle. Retrieved 2020-07-30.