Domain,  Name,  Service, 

Domain Name Service (DNS)




A domain name service is a term associated to information related to a domain name. Sort of like a phone book the DNS server interoperates a domain name such as www.foobar.com and relays the IP address associated to the domain name back to the user who requested it.

DNS makes it possible to assign easy to remember names to numerical IP addresses that can be next to impossible to remember. You and I take advantage of this every day when we type in a meaningful URL like google.com or yahoo.com which both is mapped by a DNS server that points to a unique IP address. Back before DNS was available computers use to rely on the computers hosts.txt file. This file is where users would define an IP address and assign it to a hostname (eg. www.google.com).

Most operating systems today still have a host file where users can predefine IP addresses to hostnames, but the problem with this lies in when the hostname changes its IP address then the user has to go and edit the host file and change the IP address as well. On a mass scale this could become time consuming and this is why the DNS system was developed. Due to network growth such as the internet, the DNS system has become invaluable.

Paul Mockapetris originally invented the domain name system in 1983 and wrote the first implementation. Originally, Mr. Mockapetris wrote the first specifications that appear in RFC 882 and RFC 883 but as the years have passed, updates have been made to the DNS specification making his original specifications obsolete. This specification lays out the basic theory in how DNS works.

A domain name consists of two or more parts which are conventionally written separated by dots (eg. www.google.com). The right most part is com which is called the top-level domain. This can help people and companies determine what might be found at this domain. A dot (com) can be a business or personal use domain, a dot (edu) is generally associated with educations domain or websites, a dot (net) is generally associated with a internet service provider, and dot (org) is a non-profit organization. In the early days of the internet, users who wanted to register a top-level domain need to show proof of the type of business whether it is educational or non-profit in order to even obtain the top-level domain he or she was applying for, but now anybody can purchase just about any top-level domain accept dot (gov) which is reserved for government use only.

A domain name will usually have two authoritative servers associated to it. When registering a domain name, one will need to provide two DNS servers that point the domain name to its specified IP address. This does two things; if the one DNS server is unreachable the second one will take over and provide information to the requesting party. Second, this will limit the down time one might experience when there is a network error between the user and the primary DNS server.

Most owners of a domain name do not worry about DNS services; this is why you will not find DNS services sold alone. When buying a domain name, DNS services comes automatically. Depending on whether one is allowing the registrar to host the domain name and website will determine how much work one has to put into setting up his or her domain name. If you register your domain name with one company and then host the website with another, then you will have to obtain the DNS primary and secondary servers from the website service provider and provide that information to the registrar.

When setting up a domain name, make sure you have all your ducks in a row. Know the domain name you want, and all the details of who will be providing the website server to server your web pages before you go to register your domain name this will speed up the registration process and make the new domain name available for people to visit on the internet sooner if time is an issue.