Abstract: In today enterprise environment, Security is a big issue for everybody. Methods such as cryptography, VPN, etc have been developed to secure the network channel and have a complete privacy over the Internet, among them the use of, encryption, firewalls, and virtual private networks is also very common. To this era of technology Intrusion detection has come up with new expectations. Intrusion detection system also commonly called as IDS provides a complete protection to the system from attack, compromise, and misuse. It is also most commonly used for monitoring network activities. For understanding and improving the performance and security of our cyber infrastructure, Network traffic monitoring is considered as an essential function.