DNS overview and general references

• what is DNS
• what are domains and domain names
• what kinds of information are stored in the DNS

The Domain Name System (abbreviated DNS) is an Internet directory service. DNS is how domain names are translated into IP addresses, and DNS also controls email delivery. If your computer cannot access DNS, your web browser will not be able to find web sites, and you will not be able to receive or send email.

The DNS system consists of three components: DNS data (called resource records), servers (called name servers), and Internet protocols for fetching data from the servers.

The billions of resource records in the DNS are split into millions of files called zones. Zones are kept on authoritative servers distributed all over the Internet, which answer queries based on the resource records stored in the zones they have copies of. Caching servers ask other servers for information and cache any replies. Most name servers are authoritative for some zones and perform a caching function for all other DNS information. Large name servers are often authoritative for tens of thousands of zones, but most name servers are authoritative for just a few zones.

This is a list of DNS overview documents and general references. For more detailed information, DNS-related references are collected in the DNSRD documents repository.

Simple DNS Configuration Example (RIPE-192)

Probably the quickest way to get going, if you are using BIND 8 on Unix. Just cut and paste the examples and make a few changes for a working setup.

Keeping track of names

`Keeping track of names and information: the domain system', Section 5 of Introduction to the Internet Protocols by Charles L. Hedrick, from 1987. (checked 27-Jan-2008)

What DNS Is Not by Paul Vixie

A succinct tirade against some of the worst abuses of DNS by third parties. From November 2009.

What is a domain? by Mark R. Horton

Introductory paper, similar in scope but easier to read than the fundamental RFC 1034. (Original Postscript file.)