The National Institute of Information and Communications Technology (NICT) operates a Japanese space forecast center for the International Space Environment Service (ISES). Information on space weather is exchanged daily among the space weather forecast centers all over the world. Researches of space weather need data on large areas of space from the Sun to the Earth's upper atmosphere. It is necessary for researchers of space weather to access various data and to communicate among various other researchers using a network. We describe experiments on the space weather network using the Japan Gigabit Network 2 (JGN2) operated by the NICT.