Like humans communicate with each other, computers also do
communicate with each other, but not by the names; they have their unique
numbers, such as IP addresses over a network. Humans are customized to address
by the names instead of numbers to identify a person or a site. To communicate
between computers and humans, networking engineers developed a Domain Name
Server (DNS). This blog is curated about how DNS works. But before that, What
is DNS?
What is DNS?
Domain Name Server (DNS) is a system that includes a database of
the public IP addresses with website names. It acts as a resolver that converts
domain names to IP addresses. If a user wants to open Google on the chrome
page, DNS will resolve the name Google and check for the IP address in the
cache memory. Based on the IP address, the computer gets connected with the web
server and retrieves the web page to perform various actions on the Google web
page.
How Does DNS Work?
DNS works collectively to resolve the IP address for the domain
name with various DNS servers.
- If you type a domain name
in the web browser and the system can’t find the IP address in its cache
memory, it will redirect the query to the Resolver server.
- The Resolver server is an
Internet Service Provider (ISP); it checks for the IP address in its cache
memory. If it can’t find the IP address, it will further redirect the
query to the root server.
- The Root server is the top
server of the DNS hierarchy, including 13 sets of root servers around the
world. Each set of the root servers has its unique IP address. When the
root server receives the query for the IP address but can’t find it, and
sends the query to the TLD.
- The TLD server is the
Top-level Domain Server that stores various address information for the
domains such as .net, .com, .en, .org, and more. When the query is
received but can’t find the IP address, the TLS redirects the resolvers to
the Authoritative Name Servers.
- The Authoritative Name
Server is responsible for knowing everything about Domain, including the
IP address. When the query is received from the DNS resolver, the
authoritative name server should respond to the server with the IP
address.
- And the DNS resolver will communicate with the system to retrieve the web page.
Once the DNS resolver receives an IP address from various
servers, it stores the IP address in its cache memory. In case, if the computer
sends the same query for the same domain name, it can retrieve the IP address
from memory and mitigates the whole DNS Server process in the search for the IP
address.
Final Words
InfosecTrain is one of the best IT Training
and consulting platforms that offers an instructor-led training program on
various IT security and cybersecurity domains. It provides the Network Security Training course by the well-experienced
and certified trainers to cover a wide range of Networking concepts. To know
more details, check out and enroll now.
