The Domain Name System has become the largest distributed database in the world. Human usage of the internet would be difficult to imagine without something such as DNS to map IP addresses to human-readable names. We will examine the DNS structure and the query protocol. We will discuss many of the design decisions made when DNS was being conceived. We will then examine content distribution networks in the context of a creative and unforeseen use of DNS.
For another look at the idea of using DNS for CDNs (a not-very-happy look), check out Vixie2009.pdf in the Readings section.
By the end of this lesson, the student will be able to:
describe the DNS service, including mission, interaction model, nameservers, domains, zones, load distribution, and domain name types.
explain the DNS protocol, including message format, reliability, resource records, types, and caching mechanisms.
describe the navigation mechanisms of DNS nameservers.
describe the roles of the different nameservers in the DNS.
describe how a CDN operates, including goals, host-roles, URL rewriting and DNS redirection.