Now-a-day most of the work is done by internet. So web application have now become a essential part of daily life, such as online shopping, banking, social networking, enabling communication and management of personal information from anywhere. To acclimatize this increase in web application and data complexity, web services have shifted to multi-tire design. Wherein the web server executes an application front-end logic and data is outsourced to database or file server. DoubleGuard is an IDS system used to detect and prevent attacks.