What is DNS? Generic, Country & Inverse Domains :
Domain Name Server(DNS) :
The purpose of DNS (Domain Name Server) is to translate domain names into IP addresses. Whenever we use a domain name, a service is used for translating domain names into IP addresses is known as DNS. For example: www.techbaz.org might translate to 173.208.215.106. So what DNS basically translate the domain name "techbaz" into corresponding address.
If one DNS sever does not know how to translate the particular domain name, it asks another DNS server and this process continue until the correct IP address is returned. As in the above example, if one domain server does not know how to translate - www.techbaz.org , it will move to another DNS until the corresponding IP address 173.208.215.106 is returned. DNS scheme uses alphabets and it is easier to remember, but actually each domain name has an address and DNS scheme is used to convert this domain name into its corresponding address. In the Internet, the domain name space(tree) is divided into three different sections:
i) Generic domains ii) Country domains iii) Inverse domains
Generic Domains :
The generic domain define registered hosts according to their generic behavior. Each to the tree defines a domain, which is an index to the domain name space database. the first level in the generic domain section allows seven possible three character labels.
Generic top-level domains(gTLDs) :
| Domain | Introduction | Description |
|---|---|---|
| .com | 1985 | Commercial organization |
| .gov | 1985 | Government authorities (government) |
| .edu | 1985 | Organizations of the educational system (educational) |
| .org | 1985 | Nonprofit organizations |
| .mil | 1985 | Military |
| .net | 1985 | Internet providers |
| .int | 1988 | International organizations |
| .aero | 2001 | Aviation industry (aeronautics) |
| .coop | 2001 | Cooperatives (cooperatives) |
| .museum | 2001 | Museums |
| .info | 2001 | Information services |
| .biz | 2001 | Businesses |
| .name | 2001 | Private individuals |
| .pro | 2004 | Specific professions (professional) |
| .cat | 2005 | Supporters/Users of the Catalan language and culture (catalan) |
| .jobs | 2005 | Company job advertisements |
| .jobs | 2005 | Company job advertisements |
| .mobi | 2005 | For mobile-optimized websites (mobile) |
| .tel | 2005 | Telecommunication |
| .travel | 2005 | People, companies, and organizations in the travel industry |
| .asia | 2007 | People, companies, and organizations from the Asian/Pacific region |
| .post | 2012 | Members of the Universal Postal Union |
*More(huge amount) domains available on gTLDs.
Country Domains :
The country domain section follows the same format as the generic domains but uses two-character country abbreviations (Example: "in" for "India") in place of the three-character organizational abbreviations at the first level. Second level labels can be organizational, or they can be more specific, national destination.
Country top-level domain(ccTLD) :
| Domain | Country |
|---|---|
| .ad | Andorra |
| .be | Belgium |
| .ca | Canada |
| .dk | Denmark |
| .ee | Estonia |
| .fi | Finland |
| .ge | Georgia |
| .hk | Hong Kong |
| .in | India |
| .jp | Japan |
| .ke | Kenya |
| .la | Laos |
| .mm | Myanmar |
| .np | Nepal |
| .pl | Poland |
| .qa | Qatar |
| .ro | Romania |
| .sg | Singapore |
| .th | Thailand |
| .uk | United Kingdom |
| .va | Vatican City |
| .wf | Wallis and Futuna |
| .ye | Yemen |
| .zw | Zimbabwe |
*More(country domains) domains available on ccTLDs.
Inverse Domains :
The inverse domain is used to map an address to a name. This may happen, for example, when a server receive a request from a client to do a task. Whereas the server has a file that contains a list of authorized clients, the server lists only the IP address of the client. To determine if the client is on the authorized list, it can send a query to the DNS server and ask for a map ping of address to name.
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