This paper presents an approach in order to build an intrusion detection and monitor system for a local network area (LAN). This system is designed to monitor network and system activities for malicious or unwanted behavior and can react, in real-time, to block or prevent those activities. When an attack is detected, it can drop the offending packets and bring the message to network administrator.This paper presents an approach in order to build an intrusion detection and monitor system for a local network area (LAN). This system is designed to monitor network and system activities for malicious or unwanted behavior and can react, in real-time, to block or prevent those activities. When an attack is detected, it can drop the offending packets and bring the message to network administrator.