What is a DNS Server?

The Domain Name System (DNS) has become an integral part of the internet’s infrastructure in the current digital era. A DNS server is a computer that stores data on domain names and their IP addresses. Instead of utilizing IP addresses, DNS enables consumers to visit websites using domain names. In order to make it simpler for users to access websites and other online resources, DNS servers are crucial in translating domain names to their corresponding IP addresses. Your computer queries the DNS server when you enter a domain name to determine what IP address goes with that name. There is no requirement for one of these requests if you are accessing your browser on your local network and do not need to go through an external server; however, if you are accessing something from outside your local network or even just from another room in your home (like when someone else logs into their computer), then you will need access through an external server.

Types of DNS Servers

There are various types of DNS servers, and each has different functions and roles.  The following are some common types of DNS servers:

Recursive DNS Servers 

Recursive DNS servers are responsible for resolving domain names by repeatedly requesting information from other DNS servers until an IP address is found. Internet service providers (ISPs) or other businesses that connect end users to the internet often operate these DNS servers.

Authoritative DNS Servers

Authoritative DNS servers are responsible for keeping track of the DNS records for a particular domain name. These DNS servers are operated by the owners of the domain name, which could be a website or an online service provider.

Root DNS Servers

Root DNS servers maintain the root zone file and route queries to the proper TLD DNS servers. There are just 13 root DNS servers worldwide, and they are all run by various companies under the supervision of the Internet Assigned Numbers Authority (IANA).

TLD DNS Servers 

TLD DNS servers are responsible for maintaining DNS records for a particular TLD, such as.com,.net, or.org. These DNS servers are operated by businesses that are authorized by the Internet Corporation for Assigned Names and Numbers (ICANN).

Forwarding DNS Servers 

If the local DNS server is unable to resolve the request, forwarding DNS servers are used to send DNS requests to other DNS servers. Small businesses and home users who lack their own authoritative DNS server frequently use these DNS servers.

Stealth DNS Servers

Stealth DNS servers are employed to add more redundancy and failover capabilities. These DNS servers are hidden from the public and only reply to authorized DNS requests.

The ability of domain names to be quickly and accurately translated into IP addresses is made possible by the cooperation of each type of DNS server, which plays a crucial role in the infrastructure of the internet. 

Roles of DNS Servers

The management of the Internet’s address system is mainly handled by DNS (Domain Name System) servers. The following are a few of the crucial roles of DNS servers:

Translating domain names to IP addresses: Domain names are translated to IP addresses by DNS servers, which are required for establishing communication between computers through the Internet (for example, www.example.com is converted to 93.184.216.34).

Information caching: To enhance performance and reduce network traffic, DNS servers store information about previously answered queries. This facilitates to speed up subsequent requests for the same data.

Load balancing: DNS servers can be used for load balancing, which divides network traffic among several servers or data centers. This is accomplished by responding to various IP addresses for the same domain name, depending on the client’s location or other factors.

Security: In order to stop attacks like phishing, malware, and botnets, DNS servers are essential. DNS servers can assist in defending users against these threats by offering secure DNS services.

Keeping track of domain name records: DNS servers keep track of domain names, including the owner, registrar, and administrative contact details. Also, they oversee DNS server data for the domain, including IP addresses and other setup information.

Functions of DNS Servers

Users may access websites and services on the Internet thanks to DNS (Domain Name System), a hierarchical, decentralized system that translates domain names into IP addresses. Nameservers and DNS records are the two main parts of the DNS system. 

Nameservers:

Nameservers are specialized servers that store information of domain names and their IP addresses.  A nameserver receives a request from a browser whenever a user enters a domain name, and it responds with the IP address related to that domain name. Recursive nameservers and authoritative nameservers are the two different types of nameservers.

Authoritative Nameservers

Authoritative nameservers are the best source to learn about domain names and their IP addresses.  At least one authoritative nameserver is responsible to maintain the DNS records for each domain name. When a recursive nameserver receives a domain name request, it contacts the domain’s authoritative nameserver to get the IP address.

Recursive Nameservers

Recursive nameservers are responsible for answering client requests. The recursive nameserver asks one or more authoritative nameservers for the IP address whenever a client sends a request for a domain name. DNS records can also be cached by recursive nameservers to speed up subsequent requests.

DNS Records

DNS records are called data structures that are used to store details about domain names and the IP addresses that go with them. Every DNS record includes a type, a value, and a time-to-live (TTL) value. The most typical kinds of DNS records are:

A records: These records keep track of the IP address linked to a domain.

CNAME records: These records enable the linking of one domain name with another.

MX records: These records identify the mail server responsible for managing email for a domain.

NS records: These records list the domain’s authoritative nameservers.

Conclusion:

Since DNS is a crucial part of network communication, it’s critical to comprehend how DNS servers operate. Although a DNS server can be used for a variety of tasks, its primary function involves converting hostnames to IP addresses and vice versa. As a result, users can access online resources by using domain names rather than IP addresses.

In order to respond to requests from clients or other servers on your network, a DNS server also keeps information about which hosts are located at which IP addresses. This makes it possible to set up your systems, so they are always aware of where to go in order to access a computer in your company’s network (or even outside).