引入区块链的SDN路由一致性检测  

Routing Consistency Detection with Blockchain for SDN

作　　者：刘宇宸 唐菀[1] 杨喜敏[1] 张艳 LIU Yuchen;TANG Wan;YANG Ximin;ZHANG Yan(College of Computer Science,South-Central Minzu University,Wuhan 430074,China)

机构地区：[1]中南民族大学计算机科学学院,武汉430074

出　　处：《计算机工程》2023年第11期160-168,共9页Computer Engineering

基　　金：湖北省自然科学基金(2020CFB629);中南民族大学中央高校基本科研业务费专项资金(CZY22016)。

摘　　要：为使软件定义网络(SDN)能满足复杂多样的应用层网络需求,SDN控制层采用多控制器结构,然而新制定的路由策略与已有路由策略间存在路由一致性问题,可能会导致数据层流表项存储冗余和网络流量的转发环路。提出一种基于区块链的SDN路由策略一致性检测方案RCDB-SDN,利用区块链不可篡改特性存储SDN流表项特征属性等网络信息,采用基于投票的实用拜占庭容错共识机制在控制层实现对流表项集的一致性验证,并降低路由策略一致性问题给网络带来的不良影响。通过验证输出端流表项的一致性,比较新制定的路由策略与已有策略的转发效果,检测造成存储冗余的重叠路径。根据有向图的环路检测算法及转发路径关键节点上的流表项,检测引起网络流量转发环路的环路路径。基于Multichain平台针对导致路径重叠和路径环路的流表项进行仿真实验,结果表明RCDB-SDN方案的检测精确率高于WedgeTail方案,达到95%以上,并且能在一定程度上减少控制层与数据层间的消息传递次数。A multi-controller structure is adopted for the Software-Defined Network(SDN)control layer to meet complex and diverse application layer network requirements.However,there is still the problem of routing consistency between the latest and existing routing policies,which may lead to storage redundancy of flow entries in the data layer and flow forwarding loops.To address this issue,Routing strategy Consistency Detection based on Blockchain for SDN(RCDB-SDN)is proposed,whereby network information,such as feature attributes of flow entries stored in SDN switches,can also be obtained benefiting from the tamper-proof characteristics of the blockchain.By leveraging blockchain technology,RCDB-SDN can reduce the adverse impact of routing policy inconsistency on networks.The RCDB-SDN scheme verifies the consistency of flow entry sets at the control layer through a Practical Byzantine Fault Tolerant(PBFT)consensus mechanism based on voting.To detect whether path overlaps lead to storage redundancy,the proposed RCDB-SDN scheme compares the forwarding effectiveness of the newly formulated and existing routing policies by verifying the consistency of new and existing output flow entries.A circuit detection algorithm is applied with direction graphs and flow entry detection on key nodes of the forwarding path,to determine whether a path loop causes a flow forwarding loop in the current network.Experiments are carried out on flow entries leading to path overlaps and loops on the multichain platform.The results demonstrate that the detection accuracy of the RCDB-SDN scheme is higher than that of the WedgeTail scheme and can reach more than 95%,reducing the messaging times between control and data layers to a certain extent.

关 键 词：软件定义网络 区块链 路由一致性 共识机制 流表项 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]