The Domain Name System contributes a lot to today's internet infrastructure and has been developed over several decades. Unfortunately, the behavior of DNS resolvers is not fully defined by the RFC standards and therefore depends on the implementation. This causes problems for developers of DNS-related applications. Varying caching rules are one of the problematic points. This book provides an analysis of caching behavior for two resolver implementations, Bind9 and Unbound, to facilitate the development of applications using DNS caches, e.g. Stateless DNS.
Author: Dietrich Valentin