Sunday, 7 February 2021

Domain Name System

What is DNS?

DNS stands for “Domain Name System” it resolves the hostnames of internet sites alternative to IP addresses adding efficiency and even security in the process and therefore it can let you access information online by connecting domain names, like The process of DNS is converting the hostname (Such as into an IP address (Such as However, it is responsible for assigning domain names to internet resources by designating authoritative name servers for each domain.

It is a phonebook of the internet, where domain names are listed with their corresponding id’s called IP address. Instead of listing an IP address, users can enter the domain name like on their device it looks up the IP address and connects them to the location where the website is stored. Therefore each device connected to the internet has a unique IP address were other machines used to find the device.

Types of Records Stored in the Domain Name System Database

The following records are

  • SOA - Start of Authority
  • A and AAAA - IP Addresses
  • SMTP MX - Simple Mail Transfer Protocol Mail Exchanger
  • NS - Name Servers
  • PTR - Pointers for Reverse DNS Lookups
  • CNAME - Domain Name Aliases

Types of DNS Servers

  1. DNS Recursive
  2. Root Nameserver
  3. Top Level Domain (TLD) Nameserver
  4. Authoritative Nameserver

Types of DNS Queries

  1. Recursive Query
  2. Iterative Query
  3. Non-Recursive Query

Benefits of Domain Name System

  • Security Enhancement
  • Stability
  • More Reliable
  • Enables you to specify the Technical Functionality of the Database Service
  • Make Online Transaction Possible
  • Fault Tolerance
  • Proper Load Distribution of Web hosting services
  • Don’t need to Memorize Numbers
  • Domain Name System servers have Fast Internet Connections
  • Allows Online Users to Use or Browse the Internet

Drawbacks of Domain Name System

  • DNS Attacks

Variety of DNS Attacks

Domain Name Server was working for long periods, most of the people take it for granted and security also not considered when building the system, so hackers take advantage of this, by creating a variety of attacks. The following DNS attacks are

  • Reflection Attacks
  • Cache Poisoning
  • Resource Exhaustion

Also Learn about Wide Area Network



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