October 5, 2022

DNS 101: What is DNS and Types of DNS Addresses

A Domain Name System (DNS) is a key internet system that converts human-readable Domain names into IP addresses. It serves as the Internet’s phone book. Every device that is linked to the Internet has a unique Internet Protocol (IP) address that other computers can use to locate that device. DNS is a crucial line of protection against cyber-attacks for your company when configured correctly.

Smart DNS proxies change the settings in your DNS to trick websites you visit into considering you are in the right location to access their content. The DNS is the component that converts IP addresses like “” into human-readable addresses that computers can understand, such as www.google.com.

DNS assists in defending your company against online security risks. One method for enhancing security and preventing malware from spreading is the use of protected DNS servers. Additionally, secure DNS servers can improve user data privacy.

What Are Different Types of DNS?

A DNS server computer completes the name resolution procedure after receiving a query. The master servers oversee all the zones’ data, making them the zone’s supreme authority. Two authoritative servers — the primary server and the secondary server — should both have access to the data for any zone.

Primary servers, secondary servers, and caching servers are the three main categories of DNS servers. All DNS servers are not made equal, so it might be helpful for any cybersecurity or IT professional to understand how the three distinct types of DNS servers cooperate to determine domain names.

Depending on the zone, a server may be the primary or secondary for that zone. The primary has no more authority over the zones than the secondary server. The zones they manage are governed by both the primary and secondary servers. One of the main differences between a primary and secondary server is where they read their zone files.

Primary Server

The primary server is designated as an authoritative server for a zone. It performs administrative duties of the zone, such as adding subdomains or other related tasks. Additionally, the primary server provides all zone file revisions, additions, and changes that must be made. The master copy of the data is loaded from the disc when the primary server first starts up. The updates for a zone are made on its primary server, and it can provide power to both secondary servers inside and outside its zone.

It adds an additional layer of security between a user and the internet by building a list of dangerous websites and filtering out undesirable information. As a result, threats or possibly damaging attacks won’t be able to access your Domain Name System (DNS).

Secondary Servers

A secondary DNS server serves as the standby of the primary DNS server. All zone files are moved to the backup server during a zone transfer. Each DNS server has the capacity to serve many zones at once. The zone’s data is kept in duplicate on a secondary server. The primary server transfers control to the secondary server while sending data. The primary server is contacted to provide all the information for the specified zone to the secondary server.

The secondary server regularly checks with the primary to determine whether its database needs to be updated. So, rather than changing data files on a secondary server, you change them on the zone’s primary server, and the secondary server updates its files based on the primary server.

Along with primary and secondary DNS servers, other DNS server functions like caching servers and forwarders could also be employed, depending on the DNS infrastructure.

Caching Servers

Caching servers, as the name implies, only serve cached queries for DNS responses. The benefit of caching servers is that they can respond to clients’ repeated queries. Although authoritative servers might be the best option for delivering specific zone information, caching DNS servers are more beneficial from the client’s viewpoint and also in terms of cybersecurity.

The user may occasionally be led to the incorrect URL when searching for a particular website. The DNS cache has a Time To Live, which is a predefined time that, once it gets passed, the cache is deleted. Although this server needs less memory space than an authoritative server, it is unable to function on its own in the absence of primary or secondary servers.

Forwarding DNS Server

A forwarding DNS server is another option for creating a cache for clients. A forwarding DNS server’s primary function is to forward queries to another operator for resolution. This method adds another link in the DNS resolution chain by constructing a forwarding server that forwards all requests to another DNS server with recursive abilities.

This type of server allows you to benefit from a locally available cache without performing the recursive work. Forwarding to separate servers can create intriguing flexibility in separating private and public traffic. A forwarding server can ensure that private servers handle internal requests while external queries are directed by public DNS by conditionally sending requests to other servers.

Your ISP will effectively give your devices a DNS address, but companies can choose to define their unique DNS independently for added threat protection. There are several options available if you decide it’s time to move to a third-party DNS service provider, such as NordLayer custom DNS solutions. Some only prioritize speed and security, while others include additional benefits.


DNS is essential for networking and online safety. The various DNS types contribute to faster request processing and increased network security. Understanding the different kinds of DNS servers can help you select the one that will be most useful for your business requirements. Moreover, you can also modify your own DNS for greater performance and security.

About the author 

Elle Gellrich

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