ZMap performance in open DNS resolver discovery

ZMap is a famous host discovery tool. Since open DNS resolvers (ODNSes) are a specific concern host, ZMap is also widely used to discover ODNSes. This study investigates whether ZMap is suitable for large-scale ODNS discovery. For this intention, our study designs a controlled experiment to compare ZMap with our self-built system. The experiment results show that the number of ODNSes that ZMap gets is less than our self-built system. To figure out the reason for this, we have summarized three influencing factors and verified the factors by a series of experiments. Additionally, based on the research, we propose some suggestions for making ZMap perform better in ODNS discovery.