Measurement And Analysis Of Dependency In Name Resolvtion

As an important infrastructure of the Internet,the security of DNS is very important of Internet services.As a result of the DNS hierarchy structure design,the resolution of a domain often involve many authoritative server and other domains.In this paper,we measured and analyzed the dependency relationship in name resolution from the perspective of recursive resolver,research how the dependency and the connection between the authoritative servers caused by dependency affect the security and the performance of the Internet.Our work is divided into the following four parts.We designed and implemented a system of resolution data acquisition,which can acquire all possible messages of a name resolution.This system acquires data for dependency analysis,and can make the preliminary statistics of the data,gets which domains and servers are depended on heavily in current DNS.We found that except common top level domains,the servers and domains belong to Dynamic Network Service and Cloudflare are depended on heavily.We classified the name and dependencies,visual dependencies between names which directed graph for easily understanding.We proposed a method of presentation and construction of resolving path graph through which analyzing the connection of servers can be efficient.Based on resolving path graph,we calculated the least and the most time of queries in name resolution,quantified the how dependency affect the efficiency of resolution.We proposed a method of evaluate the importance of servers in the process of resolution,to reflect how the dependency affect the security of DNS.We found that hot domains pay more attention to the resolution efficiency,and most of the domains depend on some servers particularly.We found three bad configuration that exist in the domain name management,including circular dependencies,inconsistent responses between the authority servers,and invalid redundancy.By measuring for a long period of time,the dynamic changes of DNS responses and the above three kinds of bad configuration was analyzed.Although responses continuous changing,proportion of the existence of three kinds of bad configuration is almost the same.These bad configurations didn't attract enough attention.