可扩展的网络验证技术:研究现状与发展趋势

Scalable Network Verification Technologies:State of the Art and Future

互联网作为国家信息基础设施的重要组成部分,已经在各个领域发挥着巨大的作用.随着其规模不断扩大和应用持续深入,我们也面临着意图不一致的网络行为可能导致的灾难性危害.为了确保互联网的正常运行和网络行为的一致性,我们迫切需要可部署的网络验证技术,以确保网络运行时的行为与网络运维人员的意图一致.当前已经有许多关于网络验证技术的研究,这些研究帮助用户实现自动检测网络错误,并进一步分析错误产生的原因.然而,为了满足互联网规模不断扩大的需求,可扩展性问题成为在互联网部署网络验证技术的一项重要挑战.即如何在满足时间和空间复杂度约束的前提下,快速发现并排查网络策略的错误,真正将网络验证技术应用于实际,成为一个研究热点.本文从数据面验证和控制面验证两个方面出发,深入研究和总结了现有的网络验证研究工作,并探索了基于时空优化的可扩展性技术,对这些方案的特点进行了系统性分析.最后,本文总结和展望了网络验证可扩展技术的未来研究趋势,为该领域的研究人员提供一定的参考.

The Internet,as a critical component of a nation's information infrastructure,has played a significant role in various domains.However,as its scale continues to expand and its applications deepen,we also face the potential cata⁃strophic consequences of inconsistent network behaviors.To ensure the normal operation of the Internet and the consisten⁃cy of network behaviors,there is an urgent need for deployable network verification technologies that align network opera⁃tions with the intentions of network operators.Extensive research has been conducted on network verification technologies,assisting users in automating the detection of network errors and analyzing their root causes.However,to meet the increas⁃ing demands of the expanding Internet,scalability has become a crucial challenge in deploying network verification technol⁃ogies.Specifically,how to quickly identify and diagnose errors in network policies,while satisfying time and space com⁃plexity constraints,has become a research hotspot in effectively applying network verification technologies in practice.To address this problem,this paper delves into and summarizes cutting-edge research on the temporal and spatial scalability of network verification.It begins by introducing the background knowledge related to network verification and then describes the current issues and challenges faced in network verification.Focusing on the core issue of scalability,the paper thor⁃oughly analyzes existing work in achieving scalable verification from both the data plane and control plane perspectives.It provides a systematic analysis of the characteristics of these approaches,showcasing the distinctions and connections among related studies.According to the existing researches,we find that:(1)The scalability of data plane verification is pri⁃marily constrained by header space and forwarding matching rules,while the scalability of control plane verification is mainly limited by the complexity of multiple protocols and policies.(2)Although both data plane and control plane re⁃search employ similar scalable verification techniques,they address different but interconnected targets.For example,incre⁃mental computation in the data plane primarily focuses on updating packet equivalence classes,while incremental computa⁃tion in the control plane primarily deals with network models affected by configuration changes.When applying network slicing techniques,both data plane and control plane independently validate the network by dividing it into multiple seg⁃ments.(3)Compared to spatial scalability,current research places greater emphasis on temporal scalability,where reducing verification time overhead appears to be the primary pursuit of verification tools.(4)Previous research predominantly ad⁃opted a centralized verification approach,which involved collecting control plane or data plane information and then per⁃forming centralized analysis and verification.However,there has been a recent trend towards distributed verification,such as Coral and Tulkun in control plane verification.Lastly,based on the current research landscape,the paper concludes by summarizing and forecasting the research trends in scalable network verification technologies,offering valuable insights for researchers in this field.In conclusion,this paper presents a comprehensive review and outlook on the topic of scalability in network verification.It emphasizes the importance of aligning network behaviors with the intentions of network operators to ensure the reliable and consistent operation of the Internet.By addressing the challenges of scalability,researchers can advance the development of network verification technologies that can effectively verify large-scale networks within the constraints of time and space complexity.Ultimately,this contributes to enhancing the reliability and security of the Inter⁃net as a critical information infrastructure.