Analysis of SLD DNS servers state

The publication contains a brief introduction into the system of domain names on the Internet (DNS) and into DNS protocol and its functioning. The main part is a methodology for systematic examination of a domain name and its name servers, offering criteria for checking validity of DNS records and functionality and availability of DNS servers. This methodology is then implemented as a web application that allows us to perform an on-line analysis of a domain name and the evaluation of discovered errors and other problems. The second part of the implementation is a tool for bulk analysis of large number of domain names, which was subsequently used for analysis of all domain names under TLD CZ; its short results are mentioned in the end of the work