With the increase in the use of internet, the job of malicious people has been made easy to exploit vulnerabilities in existing system. Intrusion Detection System (IDS) plays a major role in computer/network security in recognizing such malicious activity called intrusion. IDSs' quick and correct detection of unknown intrusions help in reducing damage/loss to the sensitive information. IDS with such quality need to be encouraged. An IDS must analyze a different set of attributes to decide upon a monitored information as normal or abnormal.