Network operating system for managing network and making network safe

PROBLEM TO BE SOLVED: To provide a system and a method for managing a network.SOLUTION: A method to be applied in a virtual environment maintains a view of a present state of a network in the case that the present state of the network characterizes a network component including network topology, a network entity and a network element. An event is notified in accordance with a change in a network state,and one or more network elements are set. A method for managing network traffic ensures other actions and transfers provided by a network element implementing globally declared network policy and refers to high-level names, independently of the network topology and the location of the network component. Routing is executed by using ACL, and a packet is intercepted to make a sleep mode connectable to a host.SELECTED DRAWING: Figure 2