Health Assessment of 1485 Top Level Domain's Name Servers

Domain Name System (DNS) has evolved as a critical component in the accessibility of Internet services and has therefore become a key attack vector in major Internet attacks. It is essential to monitor various DNS communications parameters, take corrective actions when needed, and prevent abuse. We propose a new set of metrics that could be monitored to assess the health of a given Top Level Domains (TLDs) nameserver. We then conduct passive probes and determine the values of the proposed parameters for the nameservers serving the 1485 TLDs of the Internet. The values of the identified metrics help to detect sluggishness in performance and form the basis for arriving at a score of their health. The presented approach is scalable across the DNS hierarchy and can be repeated periodically to detect and prevent DNS abuses.