What is DNS and how it works

Created on 4 April, 2023 | 100 views | 3 minutes read

Domain Name System (DNS); is a name database where Internet domain names are found and translated into Internet Protocol (IP) ad

What Is DNS?

DNS is a system that translates domain names into IP addresses. It is necessary to access websites and devices connected to the Internet and make the Internet usable.

How Does DNS Work?

Domain Name System (DNS); is a name database where Internet domain names are found and translated into Internet Protocol (IP) addresses. The domain name system associates the name used to locate a website with the IP address that a computer uses to find that website.

When a user enters a domain name into their web browser, the browser first checks its local cache for the corresponding IP address. If the browser does not have the IP address, it sends a query to the DNS resolver. The resolver then queries the DNS server to find the authoritative DNS server for the requested domain.

The authoritative DNS server responds to the query with the IP address for the requested domain. This response is then returned to the resolver, which caches the IP address and returns it to the browser. The browser can then use the IP address to connect to the server hosting the website.

DNS uses a variety of protocols to ensure the secure and efficient transmission of data between the DNS client, resolver, and server. These protocols include the Domain Name System Security Extensions (DNSSEC), which provides cryptographic authentication and integrity for DNS responses, and the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP), which are used to transmit data between devices on the internet.

In conclusion, DNS is a critical technology that allows users to access websites and other internet-connected devices using easy-to-remember domain names. DNS works by translating domain names into numerical IP addresses, using a hierarchical and distributed architecture that relies on DNS clients, resolvers, and servers. By providing efficient and secure access to internet resources, DNS plays a vital role in the functioning of the internet.

DNS Server Types

let's take a closer look at four main types of DNS servers: recursive, root name, TLD, and authoritative.

Recursive Server

A recursive DNS server is responsible for querying other DNS servers to obtain the IP address of a domain name requested by a client. Once the server receives a query, it searches its cache for the IP address. If it's not found, the recursive server contacts other DNS servers until the IP address is found. Recursive servers are usually provided by Internet Service Providers (ISPs) or used by end-users directly.

Root Name Server

The root name server is the first point of contact for recursive DNS servers. It holds information about the top-level domain names (.com, .net, .org, etc.) and their corresponding TLD servers. There are 13 root name servers worldwide, which are managed by various organizations under the supervision of ICANN (Internet Corporation for Assigned Names and Numbers).

TLD Server

TLD (Top-Level Domain) servers contain information about the domain names that share the same TLD. For example, the .com TLD server stores information about all domain names that end with .com. TLD servers are responsible for directing queries to the authoritative name servers that contain specific information about a particular domain.

Authoritative Name Server

An authoritative name server is a final authority on the IP address associated with a domain name. It holds information about a specific domain name and its corresponding IP address. When a recursive server receives a query for a particular domain, it contacts the authoritative name server for that domain to obtain the IP address.

Understanding the different types of DNS servers can help you troubleshoot connectivity issues and optimize network performance. Recursive servers are usually provided by ISPs or used by end-users directly, while root name servers, TLD servers, and authoritative name servers are responsible for managing the global DNS infrastructure. By working together, these servers ensure that internet users can easily access websites and other online resources using human-readable domain names.