Structure of an Internet Address | Hosts File


When the internet at its early stage of growth period US military, colleges and academics largely used it to exchange data. At that time they used One Master Server called ‘Root’, which holds the entire set of IP addresses. The IP Addresses were held as pure text in a file called ‘Hosts’ held in a sub-directory on the ‘Root’ Server.

Example->Unique IP address of the internet server followed by domain name.

 IP Address                    Domain Name             Microsoft


When any Client computer request for information with any Internet Server using browser software, the client sends a broadcast message using the Server’s Domain name as the identifier. ISP’s Internet Server intercepts this request and check the ‘Domain Name’ is known to by the Internet Server or not. If the ‘Domain Name’ be unknown, then the Internet Server will route this broadcast to an InterNIC Root Server.


In the InterNIC Root Server’s Hosts file the domain name will be mapped to an IP address. This IP address will be returned to the ISP’s Server. The ISP’s server will now pass this IP address to the clients browser. Now Clients browser will now broadcast a request to connect directly to the internet server using its IP address.


As soon as this connection established a link will be setup between the Client and the internet Server. Web server software running on internet server will takes care of connecting a Client to the Virtual Domain if this IP is Virtual Domain as required.  Once the client connects to the appropriate domain, the web server software sends first HTML page INDEX.HTML or Index.htm file to the Client.


In case if the ISP known the IP already because some other client browses that Internet Server then It will route the new client from cached on the ISP’s server.


Structure of an Internet Address is

Where http is the communication protocol, www is the notation for world wide web, .microsoft is the registered domain name associated with the IP address of an Internet Server and .com is the server provides commercial services to clients who connects to it.


To search IP address for name resolution takes place. A unique IP address will be returned by InterNIC for this domain name when it is resolved.