November 8, 2019

What is DNS and How Does it Work

DNS or Domain Name System is like an all-embracing directory of the internet, which contains all the domain names of the websites hosted on the World Wide Web. When a user tries to accesses any type of information online, the DNS translates the domain name to the IP address of the device so that the internet browser can load the content of the website on it. Every device connected to the internet has a unique IP address, which is used by other machines to locate the device and deliver the requested information. DNS helps to eliminate the need to memorize the numerical IPv4 address or the alphanumeric IPv6 address, so that the user can use the internet easily.

How Does DNS Work

The DNS server converts the hostname, such as “www.example.com”, into a simple, computer-friendly IPv4 address, such as 192.168.1.1, or an IPv6 address, such as 2041:0dc8:75a3:0340:04b3:8a2e:0370:7a34. This makes it easier for web servers to find the user’s device easily. When the user searches for “example.com” on the web browser, the DNS translates the search query to a machine-friendly address to locate the website. All this is done in a fraction of a second, and requires no additional interaction from the user to access the website content.

There are four components of a DNS server, which work together to load a web page on the user’s device. The first one is the DNS recursor, which receives the search query from the user via the web browser. The DNS recursor would then decode the request and pass it on to the root nameserver, which is the second part of a DNS server, to translate the hostname into an IP address. The root nameserver then directs the search query to more specific locations in order to find the intended result.

The third constituent of a DNS server is the top-level domain nameserver or TLD server, which searches for the specific IP address on the internet. Typically, the TLD nameserver resembles the last part of the hostname, such as “com” in “example.com”. The fourth element of a DNS server is authoritative nameserver. This acts like a dictionary for the internet, wherein the hostname is detailed with a brief definition, so that the server can find the specific IP address. If the authoritative nameserver has access to the information requested, it would return the IP address for the specific hostname to the DNS recursor to deliver the result of the initial search query.