Research Of Load Balance And DDOS Attack Detection Technology Based On SDN

Nowadays, with the popularization of the Internet, computer network technology is at a stage of rapid development. With explosive growth of Internet in a variety of business, users have higher requirements in network transmission bandwidth, speed and safety. In traditional network, the wide range of network protocols and network architecture is complex, maks it difficult that network managers timely and effective maintenance the faults and safety issues of network. How to improve comprehensive performance of network and designe to be able to fit the flexible network architecture becomes what researchers need to solve. In recent years, SDN (Software Defined Networking) technology provides some new ideas and methods for network innovation research.Compared with traditional network, SDN network separates the data plane and control plane. Switches in the network just provide data-forwarding capabilities and global network management is finished by controllers. Controllers developers master the network parameters by controllers and use the controllers to provide application layer interface programming for the network flow. Controller controls data transmission in the network by distribute flows, to achieve flexible and efficient allocation of network resources. SDN network is based on open programming and it does not need to rely on specific hardware devices, thereby it significantly reduces busines deployment and maintenance costs.OpenFlow Protocol is the core technology of SDN network, it is the most important south open protocol standards of SDN. In SDN network, controllers communicates with the switchs by OpenFlow Protocol. This paper outlines the current situation and development of SDN, describes SDN network architecture, Open vSwitch and Mininet. Requirements for SDN network, we combined traditional network load balancing and DDOS attacks detection technology research. The main tasks are as follows:Firstly, this paper proposes a server load balancing technology based on traffic in SDN network environment. As traditional network load balancing technology is unable to quickly response and dynamic adjust to network emergencies, the scheme uses SDN controllers to detect the flow of each switch port, calculates the value of velocity imbalance of the entire network topology the Z score method and determines whether the network needs to be load-balanced by the way of threshold detection. It determines the server redirects the data flow by a mixture of exponential smoothing method to calculate the velocity value, SDN controller distributes flow tables to complete the diversion of traffic and implements load-balance of servers. The experiment shows that this technology implements the dynamic adjustment of the load on the server and reduces "jitter" phenomenon of frequent traffic scheduling between servers.Secondly, this paper presentes a DDOS attacks detection based on traffic characteristics in SDN network. As SDN network may appeares numerous DDOS attacks problem based on flow characters, the paper makes SVM-KNN algorithm by introducing the Relief algorithm for weighted improvement. At last, it makes algorithm applied to the SDN network environment under DDOS attacks detection based on traffic characteristics. The experiment that is built by SDN network simulation environment validate this algorithm has a highe attack detection rate and it can be well used under the environment of SDN.