The domain name to IP resolution process – Part II/IV – DOMAIN NAMES

Tags: backend process of domain name to IP conversioncomplete domain name to IP resolutiondnsdns for beginnersdns query processdns workingDomain namedomain name conversiondomain name resolution for beginnersdomain name to IPdomain name to IP behind scenesdomain name to ip resolutiondomain namesDomain namesdomain to IPdomain to IP conversionhow domain name is mapped to IPIP addressessub-domainsworking of dns query

Published on: May 25, 2010 by Arnold Pablo

The domain name to IP resolution process – Part II/IV – DOMAIN NAMES


Before I go on to the query process, I would like to present a small briefing about Domain Names basics :

The Domain Name System uses a tree (or hierarchical) name structure. At the top of the tree is the root node followed by the Top-Level Domains (TLDs), then the Second-Level Domains (SLD) and any number of lower levels, each separated with a dot. TLDs are split into two types:

1. Generic Top-Level Domains (gTLD): For example, .com, .edu, .net, .org, .mil, etc.

2. Country Code Top-Level Domains (ccTLD): For example, .us, .ca, .tv, .uk, etc.

For instance, is actually a combination of an SLD name and a TLD name and is written from left to right with the lowest level in the hierarchy on the left and the highest level on the right:


The term Second-Level Domain is technically precise in that it defines nodes at the second level within the domain name hierarchy. There are also Third-Level Domains, which are especially relevant with ccTLDS. Any name just which is to exist in the Internet’s name space just to the left of the gTLD or ccTLD ( i.e. SLD ) should be brought from an Accredited Registrar or simply, Registrar.

So what is

From our reading previously on domain names basics, we can see that if we assume a domain name, is built up from www and The domain name part was delegated from a gTLD registrar, which in turn was delegated from ICANN. The owner of the domain chose the www part since they are now the delegated authority for the domain name. They own everything to the left of the delegated domain name, in this case *. The leftmost part, the www in this case, is called a host name. Keep in mind that only by convention do web sites use the host name www (for World Wide Web), but a web site can be named—few may think of typing this into their web browser, but that does not invalidate the name! Every computer that is connected to the Internet or an internal network and is accessed using a name server has a host name.

Consider some examples:  a company web server  a company file transfer protocol server  a normal PC

A host name must be unique within the delegated domain name, but can be anything the owner of wants. Say, he can make as the web server. There is no protocol or convention to name web servers starting with www. It is usually given for better understanding that the name starting with www will be the web server and that starting with ftp will be the ftp server.

One more thing to note is that & need not be 2 different hosts (separate machines). It can also be 2 different sub-domains of on the same host!

To summarize: the owner can delegate, in any way they want, anything to the left of the domain name they own (or were delegated). The delegated owner is also responsible for administering this delegation.

* For .name TLD, the registry handling it, Verisign Inc., places some restrictions regarding the registration of third level domain names and it’s ownership. You may find further details on it at :

Category : Linux, Training

Arnold Pablo

Arnold Pablo

Technology always fascinated me and continues to do so. I started my career back in 2004 as a Junior System Admin and worked in various capacities both in technical and managerial roles. I love to experiment and try out new OSS projects and in free time, go for cycling to the interiors of God's own country, Kerala!

You may also read:


Add new commentSIGN IN

Let's Connect

Get new updates


$0.000 items