Introduction

DNS : Domain Name System

Distributed System for names and addresses

Before DNS : a centralized file HOSTS.txt at NIC, and FTP transfer by every network administrator for updates.

Internet growing during eighties and SMTP deployment justified the DNS design .

First Motivations :
   [host name -> IP address],
   [SMTP address -> IP addresses of mail servers],
but many other Data types exist.

IAB Protocol Standard (STD13) : RFC1034, RFC1035 (1987);
first specification : RFC882, RFC883 (1983).

DNS = Naming Scheme + Distributed Data Base System

Naming Tree is globally Unique.

Very High Distribution :

• for Data,
• for Data Access,
• for management responsibility.

Vital element in the Internet operational behavior;
Many extensions are under discussion or experiment at IETF;
Also strategical and political stake from business users : " Internet governance";

=> big concerns with respect to DNS evolution or design of new features ...