Suresh Kumar Pakalapati's Linux Administration: How a DNS works

Friday, September 2, 2011

A User opens a web browser and tries to connect towww.google.com. The operating system not knowing the IP Address for www.google.com, asks the ISP's DNS Server for this information.
The ISP's DNS Server does not know this information, so it connects to a Root Server to find out what name server, running somewhere in the world, to know the information about google.com.
The Root Server tells the ISP's DNS Server to contact a particular name server that knows the information about google.com.
The ISP's DNS Server connects to Google's DNS server and asks for the IP Address for www.google.com.
Google's DNS Server responds to the ISP's DNS server with the appropriate IP Address.
The ISP's DNS Server tells the User's operating system the IP Address for google.com.
The operating system tells the Web Browser the IP Address for www.google.com.
The web browser connects and starts communication withwww.google.com.

Graphical Representation