DNS Linux – Introduction

Abu Syams — Thu, 15 Oct 2009 10:42:57 +0000

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Introduction

Domain Name System (DNS) converts the name of a Web site (www.sekolahlinux.com) to an IP address. This step is important, because the IP address of a Web site’s server, not the Web site’s name, is used in routing traffic over the Internet. This blog will explain how to configure your own DNS server to help guide Web surfers to your site.

Introduction to DNS

Before you dig too deep in DNS, you need to understand a few foundation concepts on which the rest of the chapter will be built.

DNS Domains

Everyone in the world has a first name and a last, or family, name. The same thing is true in the DNS world: A family of Web sites can be loosely described a domain. For example, the domain sekolahlinux.com has a number of children, such as www.sekolahlinux.com and mail.sekolahlinux.com for the Web and mail servers, respectively.

BIND

BIND is an acronym for the Berkeley Internet Name Domain project, which is a group that maintains the DNS-related software suite that runs under Linux. The most well known program in BIND is named, the daemon that responds to DNS queries from remote machines.

DNS Clients

A DNS client doesn’t store DNS information; it must always refer to a DNS server to get it. The only DNS configuration file for a DNS client is the /etc/resolv.conf file, which defines the IP address of the DNS server it should use. You shouldn’t need to configure any other files. You’ll become well acquainted with the /etc/resolv.conf file soon.

Authoritative DNS Servers

Authoritative servers provide the definitive information for your DNS domain, such as the names of servers and Web sites in it. They are the last word in information related to your domain.

How DNS Servers Find Out Your Site Information

There are 13 root authoritative DNS servers (super duper authorities) that all DNS servers query first. These root servers know all the authoritative DNS servers for all the main domains – .com, .net, and the rest. This layer of servers keep track of all the DNS servers that Web site systems administrators have assigned for their sub domains.

For example, when you register your domain my-site.com, you are actually inserting a record on the .com DNS servers that point to the authoritative DNS servers you assigned for your domain. (You can also read more basic networking in network systems).

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