Abstract: Currently, research on the domain name system mainly focuses on domain name classification, domain name security, domain name server performance, and other aspects, while research on the relationships between domain name servers is relatively rare. Through a measurement experiment lasting 31 days on over 8 million DNS servers, basic information on 250 million recursive query events, including the relationship between over 1.3 million recursive servers, was obtained. Statistical analysis of recursive query events was carried out based on capacity, response specification level, and other mea- surements. Statistical analysis was carried out on servers that support recursive queries using two classification methods: function and response status. A server stability measurement is proposed to describe the stability of server responses. The relationships between DNS servers are displayed using an undirected graph. Finally, attempts are made to explain and analyze unreasonable phenomena that appeared in the statistical results of server classification

Key words: public DNS service, Internet measurement, recursive query, stability