What Is an Internet Protocol (IP) Address?
Before we talk domains, it’s important to understand what an
IP address is.
Each computer has a unique IP address, which consists of a
set of numbers separated by periods (for example, 94.172.0.912). This set of
numbers is a language that computers use to communicate with each other over a
network.
IP addresses allow any number of internet-connected computers to be distinguished from other computers. It’s just like calling someone on the telephone. Everyone in the world has a unique telephone number, and you have to dial someone’s exact number to reach them.
What Is a Domain Name?
So what is a domain name? Let’s continue with the phone
analogy. You’ve probably got a long list of contacts saved in your mobile
phone. Each contact has a unique phone number. When you want to call someone,
you usually click on the contact’s name rather than typing in the full phone
number.
Domain names are just like a contact in your phone. Rather than typing a complicated set of numbers (the IP address) into your browser, you type in a domain name. That domain name is human-friendly and much easier to remember than an IP address. All domain names are connected to a unique IP address.
Morphology of a Domain Name
Now that we understand what a domain name is, let’s break it
down a bit more. There are three different parts of a domain name that assign meaning
to the domain.
·
Domain
name: Bluehost is the domain name in bluehost.com.
·
Top-level
domain: This is the suffix at the end of the URL. Examples include .com,
.org, or .blog.
·
Subdomain:
This is a prefix that further classifies a domain, such as subdomain.bluehost.com.
To start a website, you need a domain name, but don’t worry.
It’s easy! Bluehost provides you with a free domain name when you purchase
hosting. As soon as you select your hosting package, Bluehost will instruct you
to choose your domain name. You can select your domain name and your top-level
domain.
As long as each part of the domain name is unique, you can pick any domain name you want, and register it with a domain name registry.
So What Happens Next?
When you register your domain, you are registering with a
DNS (Domain Name System). A DNS is a database that connects IP addresses with
their corresponding domain names. It’s like your phone’s contact list for all
domain names.
When you go to your browser and type in a domain name, it will
connect with the DNS. The DNS searches through all of the registered IP
addresses and connects that domain name with the IP address.
The end result? The server returns a web page back to your browser in less than a second. It’s sort a like magic.
Identify the purpose and types of DNS including
explanations on how domain name organized and managed
The Domain Name System (DNS) is a directory of names that
matches with numbers, the numbers are the IP addresses which computers use to
communicate with each other. The DNS is a protocol which uses the TCP/IP
protocol set. It helps convert URLs into IP addresses that computers use to
identify each other on a network, it is a system that matches names with
numbers like a phonebook does. With a DNS you do not need to have the IP
address of everyone, you connect to a Domain name server, which holds a large
database of domain names and translates them to IP addresses 1. So, when you
type in a website like www.bbc.co.uk for example, your internet service
provider will request the DNS linked with the domain name and then translates
it into an IP address that a computer understands then will direct you to the
correct website. If you have previously visited the website, the computer will
first check the cache to see if it has already visited the website before, if
not it will do a DNS query to find the website.
Main DNS server types
Resolver
A resolver is the first stop in a DNS query, this acts as the middle link between the client and a DNS name server, once a DNS query has been sent from the client a recursive resolver will bring back cached data if it is found in the cache, or it will send a request to a root name server, then another request to a TLD (Top Level Domain) name server and then a last request to an authoritative name server. If the recursive resolver does not have the website that is requested in its cache, then it will go through the process of getting the IP address of the website wanted and return it. It will then store this IP address in its memory for a period time. The period of time that it is stored in the memory is chosen by the owner of the domain by using a setting called time to live2, in which how long the website stays in the cache’s memory for.
Iterative
The iterative DNS query will query a DNS server for information on a website, the user will enter a website they are trying to find and then the resolver may provide an answer from the cached memory or will ask another DNS server if they have the answer by returning the address of that DNS server, if it cannot return a definitive answer it will ask the next server. The query will start at the root server and then go down the levels according to its referrals that it receives.
Root server
The root name server for the DNS records is a server that has a big role in the translating of a domain name into an IP address for a computer, they answer requests made in the root zone of the DNS. The servers can answer queries records which are cached in the root zone. They can also divert other requests made onto the TLD server.
TLD (Top Level Domain) name server
The TLD name server is referring to the last part of a domain name, the part after the dot. TLDs made up into two categories, a country TLD and industries TLD. For example .FR for France and .GOV for governments websites. The TLD is the highest level of domain names in the root zone of the DNS for the internet. For the other domains in lower levels, it is the last section of the domain name 1. The managing of the TLD name servers is take care of by the IANA (Internet Assigned Numbers Authority) which is a part of the organization ICANN.
Authoritative name servers
An authoritative name server provides answers to an original DNS query. It does not provide answers of websites from the cached memory 3. The Authoritative name server provides answers to the recursive DNS name servers with IP mapping of the website (or other server) searched for. The authoritative name server holds the records for domain names, these can be either A, CNAME, MX, NS, SOA or TXT records. An example could be if a DNS server in a network has stored a record for a website for example www.example.co.uk, then it would be that this DNS server is the authoritative server for the example.co.uk domain.
URLs
A URL is the address of the website that you type into the
address bar in a browser. A URL is unique and cannot be shared between
different websites, it is just like a fingerprint with a person each person’s
fingerprint is unique to them and there is no other the same. A URL is
organized by the structure of different parts, this example shows the different
parts of a URL and how they are organized – https://moodle.nptcgroup.ac.uk. The
HTTPS is the protocol that is used to send data over the browser and the
website you want to connect to.
The host is “Moodle” which is the name of the web servers
where it can be accessed. Then the .ac is the second level domain, this is
showing that it is an academic second level domain and is used by universities
and colleges in the UK. Then the .uk is the top level domain, this is the
highest level of domain and shows that it is in the country of the UK by its
top level domain. This is the end of the URL and is normally either a company
(.com), country (.fr) or a government (.gov) Domain name management includes
keeping the DNS up to date, the management aspect of it is controlled using a
portal by a third-party company.
Using this portal, the personal or business website can
control DNS records which allow access the website, your blog, email and other
online assets. Lots of companies online offer services that will control your
domain names for you, these will keep your domain name from expiring by
offering an auto renewal service in with their service. Once your domain name
is up and running you can then use the portal to manage your domain and all
aspects of it easily from one place, you can there change the DNS records
quickly and easily for different domains.