Software Defined Networking (SDN) is a new network architecture that separates the control plane and the data plane and provides logically central control over the whole network. Because SDN controller combines the upper application layer and the underlying infrastructure layer, it may face the problem of single-point failure. If it is made unreachable by a Distributed Denial of Service (DDoS) ...

Distributed Denial of Service (DDoS) attacks are security attacks that prevent normal use of communication facilities. More and more DDoS attacks are occurring each day. Conventional DDoS attacks are typically based on flooding the server. Currently, other types of DDoS attacks have been observed, such as the mimicry DDoS attack. The mimicry attack is characterized by (1) gradual increase in th...

Recent events show that distributed denial-of-service (DDoS) attack imposes great threat to availability of Internet services. In this paper, we study and evaluate DDoS attacks in a random flow network model, a novel and general approach to DDoS attack prevention and tolerance. The model can be used to evaluate the effectiveness of a DDoS countermeasure framework. Following the random flow netw...

Distributed Denial of service (DDOS) attack is one of the biggest security threat to the Internet. This research paper attempts to study the DDOS attacks and its main types. The study will provide good knowledge to try for the defense measures for these attacks. The network is always vulnerable to this type of attack even after providing the security measures. This study will also focus on the ...

Distributed Denial of Service (DDoS) attacks have caused continuous critical threats to the Internet services. DDoS attacks are generally conducted at the network layer. Many DDoS attack detection methods are focused on the IP and TCP layers. However, they are not suitable for detecting the application layer DDoS attacks. In this paper, we propose a scheme based on web user browsing behaviors t...

In a Denial of Service (DoS) attack, legitimate users are prevented from access to services or network resources. Distributed DoS (DDoS) occurs if a group of attackers coordinate in DoS. When a DDoS attack occurs in a mobile ad hoc network (MANET), the attacker compromises a number of mobile nodes, which can follow different mobility patterns and have different speeds. This paper provides a sur...

A Distributed Denial of Service (DDoS) attack is a major threat to cyber security. It originates from the network layer or the application layer of compromised/attacker systems which are connected to the network. The impact of this attack ranges from the simple inconvenience to use a particular service to causing major failures at the targeted server. When there is heavy traffic flow to a targe...

Distributed denial of service (DDoS) attacks on the Internet have become an immediate problem. As DDoS streams do not have common characteristics, currently available intrusion detection systems (IDS) can not detect them accurately. In this paper, we propose a distributed approach to detect distributed denial of service attacks by coordinating across the Internet. Unlike traditional IDS, we det...

The nature of the threats posed by Distributed Denial of Service (DDoS) attacks on large networks, such as the Internet, demands effective detection and response methods. These methods must be deployed not only at the edge but also at the core of the network. This paper presents methods to identify DDoS attacks by computing entropy and frequency-sorted distributions of selected packet attribute...