Domain Name System in Computer Network

Domain Name System

Domain Name System is also called DNS. DNS was introduced by Paul Mockapetris and Jon Postel in 1983. DNS is an internet service that converts Domain names to IP addresses. When the user types any domain name in a web browser, then the DNS server converts that domain name to IP address.

Domain Name System

For example – When a user types www.javatpoint.com in a web browser, DNS changes it to an IP address 198.15.45.18. Now you see for yourself how easy it is to remember www.javatpoint.com, while how difficult it is to remember the IP address 198.15.45.18.

If one DNS server does not convert the domain name, it asks the other DNS server to convert the domain name, and the process continues until the domain name will be converted.

DNS in the Internet

On the internet, DNS is a protocol. It is used on various platforms. The tree of the domain name system is divided into three categories: generic domains, country domains, and the inverse domains.

Domain Name System

Generic Domains

It defines the registered hosts by their common actions. Every node of the tree represents a domain. It is an index of the DNS database that is shown in the figure below.

Domain Name System

It gives the 14 possible labels. The description of these labels is shown in the table.

Label Description
aero Airlines and aerospace companies
biz Businesses or firms (similar to “com”)
com Commercial organizations
coop Cooperative business organizations
edu Educational institutions
gov Government institutions
info Information service providers
int International organizations
mil Military groups
museum Museums and other nonprofit organizations
name Personal names (individuals)
net Network support centers
org Nonprofit organizations
pro Professional individual organizations

Country Domains

The country domain uses only two characters for the country abbreviations, such as (in = India). In the country domain, second labels can be organizational.

For example, TMU.ac.in.

Where,

  • TMU represents the name of the organization.
  • ac.in is represented the country domains (ac.in means academia of India).

This example is better understood in the figure below.

Domain Name System

Inverse Domain

The inverse domains are those domain name system that is used to map an IP address to a domain name. The example of the inverse domain is shown in the figure below.

Domain Name System