Root Mirror Sites Identification and Service Area Analysis

The operation of today’s Internet can only be achieved with the domain name system (DNS), and the essential part of the DNS is the root servers. Adding anycast mirrors has been used to maintain the security of root servers, but many problems accompany this technique. In this paper, we used 36198 probe points deployed worldwide to probe 1160 root mirror sites and analyzed the data with root mirrors’ identification and localization (RMIL). RMIL is a method to identify and locate root mirrors. It contains probing and analyzing the network services ID (NSID) and traceroute data to identify and locate root mirror sites. Using this method, 821 (70.78% of the total) sites were accurately identified and located, and city-level localization was achieved for 281 other sites. Finally, the identification results were used in the service area analysis. The analysis contained multiple dimensions: locations, autonomous system numbers (ASN), internet service providers (ISP), and IPV4 prefixes. As such, we helped identify and locate root mirror sites more precisely and discover which ones have a greater service area in different dimensions.