An intrusion detection system (IDS) monitors events occurring in a computer system or a network and analyzes them for signs of intrusions. Intrusion detection (ID) is a type of security management system for computers and networks. An ID system gathers and analyzes information from various areas within a computer or a network to identify possible security breaches, which include both intrusions (attacks from outside the organization) and misuse (attacks from within the organization). A network-based IDS (NIDS) often consists of a set of single-purpose sensors or host computers placed at various points in a network. These units monitor network traffic, performing local analysis of that traffic and reporting attacks to a central management console. Network-based intrusion detection is generally implemented using two approaches: rule-based and anomaly-based.