DNS/Domain Name System

The Domain Name System

The domain name system is one of the essential parts of the internet, Weather you enter a domain name into your browser, or you send an email message, You are using DNS to find the address.

The internet is basically addressed by numbers, every machine that is connected to the internet has a number or more specifically and IP address (currently IPv4 or IPv6), DNS is the way we give those numbers names we can remember, So now saying easywebdns.com is like saying 75.125.124.243, i would bet you prefer to memorize the name and not the number.

But there is more to DNS than mapping names to numbers, Some of the uses include load balancing between servers (Round robin for example), Or dynamic name allocation (See Wildcard A records for example), Even more, Using names rather than numbers allowed us to have fewer numerical addresses serve many different purposes and save our limited IPv4 addresses (See virtual hosts).

DNS is a distributed system and a hierarchy, every part of the system refers you somewhere else until you (or software like your browser) know/Knows the exact address you need to request data from or send data to.

The decentralized hierarchy allows everyone to manage there own zones (You will get more familiar with the words zones and records very soon), and since everyone can manage there own zones, this makes life much easier and faster for everyone who works in making the Internet's infrastructure.

There are 2 parts of this system, Just like the client and server model, DNS has a similar model, DNS servers, and DNS resolvers in more or less the same way.

Now to some magic, Ready, Steady, Go (Ready, Set, Go)

1- A short History lesson : When it comes to DNS, History is not about irrelevant things from the past, it is rather a very helpful background to how DNS worked, Evolved, is evolving, and where it is going, My advice would be not to skip the section just because we are internet people who think history is a waste of time.

2- A short introduction to DNS : This article explains DNS in the simplest of terms, Not going into any detail about the system.

3- DNS Servers : DNS servers are softwares that are responsible for storing and serving address information for Zones.

4- DNS Resolvers : DNS servers store information about addresses pointed to by DNS records, Resolvers are the softewares that querry for those addresses.

5- Setting up bind : BIND is the defacto standard nameserver, Here i will setup Linux Debian Lenny on my network on an old P3 computer i have, and then install BIND, You can install bind in a virtual machine on your computer as well if you like.

5.1- Configuring the bind resolver

Unorganized topics

x- Glue Records