JMU
The Domain Name System (DNS)
An Introduction


Prof. David Bernstein
James Madison University

Computer Science Department
bernstdh@jmu.edu


Overview
DNS Names
DNS Names (cont.)
DNS Name Servers
The Distributed Approach that is Used
Types of DNS Servers
Recursive Queries
Recursive Queries (cont.)
images/dns_recursive.gif
Non-Recursive Queries (a.k.a. Referrals)
Non-Recursive Queries (cont.)
images/dns_non-recursive.gif
Transport Layer Protocols
Message Format
Format of Resource Records (RRs)
Interacting with DNS