Most of us finds it easy to remember names rather than numbers while
machines can understand numbers only, and that too, two digits 0 and 1.
Humans, right since the big bang, has survived and tamed the situation to
his advantage and exactly that happened with machines as well. We tamed
machines to understand the names we call them and we were quite successful
in that.

Here we are going to discuss in brief, that technology by which name to
number (domain name to IP) translation happens.

Domain names, where IT all starts! These domain names are associated with
IP addresses which makes them accessible in the internet. So curiosity
rises over how and what makes them ready for the process. Here we discuss
about how a website is accessible at your fingertips by just typing it’s
name.

We know how important a domain name is for a website. The names must be
catchy one to grab everyone’s attention. Everyone includes robots also.
Domain name registration is the initial step for getting into online
business. The domains are registered with a registrar which is a company
accredited by ICANN.

Domain name are mainly of three parts.

Take for eg: www.hostcats.com. Here the first part i.e www is known as
TLD(Low level Domain), the second part is hostcats which is the domain
name and the third part is known as the TLD (Top Level Domain) which
includes .com,.info.,.org etc.

Accessing a website

You just type the website address in the browser. The browser checks with
the default nameserver of the system to locate the IP address so as to
resolve the domain name. If the domain name is present in the cache of the
ISPs nameserver then it returns the IP address and the website is accessed
and machine sends the website IP and the name to the webserver.

Let us consider the case where it is not there in the cache. In that case
the ISP’s name server inturn contacts the root name servers which handles
the TLD(.com, .info, .biz etc). They will be delegating the query to the
name servers of respective TLDs who will then delegate to authoritative
name servers it has on its glue records.

Name Servers are responsible for resolving the domain names/hostnames to
the IP address or vice versa. When the domain names are registered with a
domain name registrar, their installation at the internet registry
requires the assignment of primary name server and a secondary name
server. Usually the secondary one act as a backup for the primary name
server. i.e ns1.hostcats.com will act as primary nameserver and
ns2.hostcats.com is the secondary or backup nameserver.

Did you know DNS system is one of the largest and active database on the
earth ? We can’t imagine how millions of website are accessed in a second.
They even maintains the uniqueness of a domain name since no duplication
is allowed. We even doesn’t know that we are accessing name servers a
hundred times during browsing and emailing.

As we said earlier name-servers converts the domain names to IP address.
But the conversion is not an easy process at all. There are billions of IP
address currently in use, billions of DNS requests are made each day,
domain names are registered with their IPs everyday, domain names and IPs
change everyday. This makes the conversion a herculean one. So how the
mother of databases going to resolve this issue ?

The IP or Internet Protocol helps it in resolving them. Each machine is
assigned with an unique IP. Every machine on the internet have it’s own IP
address. For a server the IP will be static and for a desktop at your
home, usually the IP will remain unique for a particular session only i.e
dynamic IPs. You can find your own IP, by visiting
http://www.whatismyip.com

There are 13 root nameservers in the Domain Name System. They directly
answers the requests for records in root zone. They returns an
authoritative name servers for the appropriate TLD.

An authoritative name server is a name server that directly answers to DNS
queries not just cached answers obtained from other name servers. The one
which answers from the cache or from querying other name servers is
recursive or caching name servers. These name servers store the query
results in the cache and then access them from the cache later. But the
results remain in the cache only for a certain time i.e time to live
(TTL). After that it expires from the cache and the whole process has to
be done again.

If you ever worried why are you are seeing old website even after
switching to HostCats, it is because of this cache we just mentioned
about. Just have patience for 24 hours which is usually the TTL and DNS
get cleared then and you will see the new sites.

Name server registration

If you are our shared hosting customer, you may not need to worry about
this part. But for our dedicated customers, the below section will explain
why the extra step of registering your private name servers.

As we have explained above the name servers are required for a website to
be accessed. These name servers won’t recognize the address until you have
registered them. Just like we register a domain name, we need to register
the name servers with your domain registrar to avoid the typical
chicken-egg problem. For a website hosted at hostcats shared servers the
nameservers registerd will be ns1.hostcats.com and ns2.hostcats.com. These
nameservers will be having the IPs of the nameservers in which their zone
is situated at.

Similarly you need to register ns1.yourdomain.com and ns2.yourdomain.com
for you to be able to use your own nameservers for yourdomain.com.
Different domain registrars, have different tutorials available for
registering the nameservers. Those steps for different registrars will be
explained in another article.

The dedicated and reseller customers can buy a dedicated IP and point
their nameservers to this IP and also will be having an option to change
the nameservers with respect to their domain names.