The Domain Name System is also known as the “phonebook of the internet.” When you want to access a certain website, you enter the domain name, like netflix.com or bbc.com. These are human-readable addresses. On the other hand, web browsers interact through Internet Protocol addresses, a “computer language.”
The main purpose of DNS is to translate domain names into IP addresses so that web browsers can lead us to our desired website. It makes it easier for humans to access a website without memorizing or entering long alphanumeric addresses. When configured correctly, the Domain Name System is a crucial line of protection against cyber-attacks and unauthorized entry into our network systems.
History of Domain Name System (DNS)
In the early days of the internet, the whole IP address of the website had to be entered to access a certain website. To counter this issue, a system was developed by Paul Mockapetris in the early 1980s that automatically converts IP addresses into domain names.
How does DNS work?
To better understand the process behind the DNS resolution, we need to learn about the different hardware components that the DNS query must pass through. In loading a webpage, there are 4 DNS servers involved. These are DNS recursor, Root nameserver, TLD nameserver, and Authoritative nameserver. The domain name that the user enters must go through all four mentioned servers in a typical DNS query before the IP address is returned. Let’s read about these 4 servers in detail.
Root Name Server:
The root server is the first step of domain name translation. The root name server is responsible for providing a list of trustworthy name servers connected to the appropriate TLD when requested. It is also used in maintaining the root zone records or a “library” of the DNS.
DNS recursor or Recursive DNS Server:
The DNS recursor receives the request from the DNS client through web browsers. It is also responsible for making requests to the other three DNS servers in order to satisfy the client’s DNS query. It provides the answer to the DNS queries if it is cached. If not, it forwards the queries to the next servers.
Top Level Domain Name Servers:
This server directs the query based on the top-level domain. A TLD name server maintains the second-level domain’s IP address that is part of the Top Level Domain name. The domain name server receives the query after that and returns the IP address of the website.
Authoritative Name Server:
The server can be considered a dictionary where a specific name can be translated into a definition. In the list of nameserver queries, this is the last step. This server looks for access to the requested query and returns the IP address back to the DNS recursor, that made the initial request.
There are two categories of authoritative name servers. The first one is a controller server or a primary name server. The second is an agent server, also known as a secondary name server.
Public vs. Private DNS servers
You are assigned a DNS server when you use a device that can connect to the internet. Usually, your internet service provider is the one who provides it. It is also possible to set up your own DNS server. This creates a distinction between two types of DNS servers: public and private.
The public DNS maintains the domain names that are available publicly. It doesn’t require any setup, and anyone with an internet connection can access it.
The private DNS maintains a record of internal websites and usually resides behind a company’s firewall. It is a much more discrete DNS configuration method than public DNS. DNS handling is one of the most important decisions an organization or an individual must take when managing cybersecurity issues.
Why is Using a Private DNS Server a Better Option?
Private DNS servers are a much safer option as compared to public ones. They can help in filtering content and are more reliable. They provide an additional security encryption protocol (HTTPS and TLS) that hides your DNS query over the network. These protocols can save you from malware attacks and DDoS attacks offering you an added security advantage. This helps in the isolation of private information and helps build multiple layers of security. You can read about this in detail at https://nordlayer.com/blog/public-vs-private-dns-servers/
Having an understanding of the different kinds of DNS servers can help you select the one that will be most useful for your organization’s requirements. Moreover, you can also modify your own DNS for greater performance and security, contributing to a granular security system.