Abstract: INTRUSION DETECTION SYSTEM [IDS] are the process of identifying and responding to malicious activity targeted to computing and network resources. Intrusions are the activities that violate the security policy of system. The process used to identify intrusions. Today network securities are used in various applications like protect vital information while still allowing access to those who need Trade secrets, Medical records etc. In this paper going to see about different types of attacks, mechanisms to prevent the attacks and simulations.

Keywords: Intrusion Detection System, Methods of IDS, Protocols, Attacks.