Date Added: Dec 2011
Intrusion detection is the act of detecting unwanted traffic on a network or a device. A Intrusion Detection System (IDS) provides a layer of defense which monitors network traffic for predefined suspicious activity or patterns, and alert system administrators when potential hostile traffic is detected. Intrusion detection faces a number of challenges; an intrusion detection system must reliably detect malicious activities in a network and must perform efficiently to cope with the large amount of network traffic. Network based intrusion detection are the most deployed IDS. An IDS can be a piece of installed software or a physical appliance.