However the continually increase of network security threats can also be one of the most frequent reasons for this network condition. Reasons for all these can be different, such as poor configuration of network architecture, or use of unrequired routing protocols, etc. Slowdowns in the network performance, connectivity loss or shutting down of terminals within the network for unknown reasons, are among the other problems. There is no Intrusion Detection System IDS that can alarm or inform for attacks or malfunctioning of the network. Network performance decreased during last days and the reason is unknown. Imagine a working environment comprised of a number of switches, routers, some terminals and file servers.
