Research On ARP Flooding Suppression In Multi-Controller SDN Networks

The SDN network abandons the traditional closed network architecture model and adopts a flexible three-layer SDN network architecture.It has been gradually applied in CENI test bed,AT&T network and Google data center and other scenarios.In the SDN network,the process of establishing end-to-end communication still adopts the ARP protocol mechanism to discover the destination terminal.As the scale of the network continues to expand,ARP broadcast packets occupy a large amount of bandwidth,and the problem of broadcast storms has become an urgent problem to be solved in network deployment and implementation.At present,there are two main difficulties in the research on ARP flood suppression:one is the poor expansion performance,the performance of controllers registering a large number of terminals or the performance of switches processing terminal messages is restricted,and it is difficult to meet the needs of large-scale networks.Another is that it consumes many resources.Proactively collecting host information affects the controller overhead,occupies too many controller resources,increases maintenance costs,and has low performance.Focusing on the problem of ARP flood suppression in SDN networks,we analyze many problems existing in the process of ARP flood suppression in existing research,and build an overall framework for ARP flood suppression based on distributed multi-controller SDN networks.Then,we propose two flood suppression methods in the ARP flood request phase and the ARP unicast response phase.In the ARP flooding stage,due to insufficient network scalability,excessive control plane resource consumption,the inability of a single controller to support network robustness,and limited software architecture capabilities.We propose a multi-controller SDN network ARP flood suppression method,design an ARP flood suppression algorithm based on IP address similarity,use the setting of IP address prefix threshold,and implement the management of storage entries between multiple controllers through a strong consistency model,and then divide the flooding range and reduce ARP requests Messages flood the SDN network.Then through the test bed to carry out the experimental verification.With the collection of ARP flooding request packet information,the scope of flooding is more accurate,and the flooding packets of the entire network are gradually reduced,effectively reducing the impact of ARP flooding on multicontroller SDN networks.In the ARP response stage,because it has the same problem as the ARP flood stage,we propose a two-stage ARP flood suppression method based on "store-block",and design a "store-block" two-stage suppression algorithm.The ARP suppression table entry among multiple controllers uses a strong consensus mechanism to achieve information synchronization,and then blocks matching ARP flooding request messages,achieving the goal of ARP request flooding suppression in SDN networks.Through comparative experiments on flooding time,flooding range and controller overhead,this method can effectively suppress ARP flooding packets and reduce the generation of broadcast storms.