This paper examines how the Network Management Systems could aid in the detection of the DDoS attacks so that the losses from these could be minimized. The classifications of DDoS Attacks and their Defense Techniques have been classified in this paper to have a close look at the DDoS Problem and its severity. | ISSN:2249-5789 Manish Saxena et al , International Journal of Computer Science & Communication Networks,Vol 2(5), 607-614 Classification of DDoS Attacks and their Defense Techniques using Intrusion Prevention System Mohd. Jameel Hashmi1, Manish Saxena2 and Dr. Rajesh Saini3 1 Research Scholar, Singhania University, Pacheri Bari, Jhujhunu, Rajasthan, India. Pin - 333515 jam_yas@ 2 Asst. Professor, MCA Department, FGIET, Raebareli, UP, India. Pin - 229001 , URL : 3 Asst. Professor, Singhania University, CSE Department, Pacheri Bari, Jhujhunu, Rajasthan, India. Pin - 333515 Abstract Distributed Denial of Service (DDoS) Attacks has been increasingly found to be affecting the normal functioning of organizations causing billions of dollars of losses. Organizations are trying their best to minimize their losses from these systems. However, most of the organizations widely use the Intrusion Prevention System (IPS) to observe and manage their networks. One of the major functional areas of a IPS is DDoS detection and DDoS Management. This paper examines how the Network Management Systems could aid in the detection of the DDoS attacks so that the losses from these could be minimized. The classifications of DDoS Attacks and their Defense Techniques have been classified in this paper to have a close look at the DDoS Problem and its severity. Keywords: DDoS, Intrusion Prevention System, Classification of DDoS Attacks, Classification of DDoS Defense Systems. 1. Introduction One of the Internet's largest security concerns is its intrinsic inability to deal with certain denial-of-service (DoS) type of attacks [1]. The term DoS referring to a situation, where a legitimate requestor of service, or a client, cannot receive the requested service for one reason or the other [2]. DoS attacks can very well be launched both locally and remotely and they range from software exploits to bandwidth .