Beginners Guide to DNS

DNS refers to Domain Name System, and is often a very difficult subject for beginners when it comes to configuring websites and servers. This article will help you understand the key terminologies associated with DNS so that you hit the ground running while setting up your website. It will also help you troubleshoot some basic problems related to websites and servers. After reading this beginner’s guide, you should be able to set up your own domain name as well as DNS server.

What is a DNS?

DNS is an abbreviation of Domain Name System. DNS helps us recognize unique addresses in a networking system in a human friendly way. A DNS links your domain name ( yourwebsite.com) to the IP address of the server where your domain is hosted. So, www.example.com will be linked to a unique address on the server ( 123.abc.982, for example) by the DNS.

What is an IP address?

Every domain is characterised by set of numbers on the internet. For example, the domain of your web hosting partner would be represented by this set of numbers called the IP address. So, if you are hosting your site on VPS server hosting, the IPV4 protocol is followed. This allows us to represent each domain by a group comprising 4 sets of numbers. In each such group, each set comprises 3 digits and each set is separated from the other by a dot (.). Therefore, the domain google.com would be represented by , say, 123.122.213.765( it is just an example). Since there are millions of domains all around the world, each IP address is unique.

Top Level Domains

Within a domain, you will always find a combination of letters beginning with.(dot). For example, in example.com, ,com is the top level domain. In example.net, .net is the top level domain and so on. Also called as TLDs, top level domains comprise .net. .com, .io. and .(dot) followed by country specific letters like in, au, us, uk, etc. Academic organizations such as universities have .ac as TLDs. Most businesses have .com as their TLD.

The most common TLD around the world is .com. Most commercial organizations use this TLD in their domain name.

What are second level domains?

Let’s look at a hypothetical domain- www.example.com. Here, the word ‘example’ is the second level domain. In www.abc.au, the combination of letters ‘abc’ is the second level domain.

Hosts

Hosts are separate computers or servers through which domains can be accessed. This access is defined by the domain owner. Many domain owners reach their web servers through their bare domain ( example.com). Most owners however define their access to servers through www.example.com.

There are other ways by which you can define your host. For example, api.example.com connects your domain to APIs, while ftp.example.com links your domain to the File Transfer Protocol.

Sub Domains

Domain Naming Systems work according to a hierarchy.

‘Com’ is a top level domain, while ‘example’ in example.com is the second level domain. If you extend the ‘example’ to something else, you get a sub-domain. For example, in ‘ www.secondexample.example.com’ , the word ‘secondexample’ is the sub-domain. DNS works this way; from the most specific to the most generic part. So a domain starts with a host, followed by a domain or a sub domain and then by the top level domain.

Name Server

The main purpose of a name server is to translate a domain name to an IP address. A name server does the most work in the entire DNS.

Summary

A DNS is a combination of various resources like domains, second level domains, hosts, name servers, etc. Understanding how DNS works is important to set up your domain and troubleshoot problems, if any.

Post Author: Clare Louise

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