Category: DNS

Recursive DNS server: How does it work?

Recursive DNS server is a crucial element of the Domain Name System. If you want to learn more about it, you are on the right page. So let’s begin.

DNS – what does it mean?

The Domain Name System (DNS) is what allows domain names to be translated into IP addresses. This is the common language that machines use to communicate with one another.

Using the Internet before DNS was a more challenging experience. To get to the domains you want to visit, you had to type IP addresses. This necessitated typing large numbers sequences into the browser. It was a time-consuming task. In addition, long digits were difficult to remember, and the odds of making a mistake were high.

It is easier to type weather than

DNS was intended to make this operation as straightforward as possible. Simple domain names are easy to remember. DNS tells machines what domains to look for in their language.

The definition of Recursive DNS server

A Recursive DNS server or DNS resolver is an expert in searching. Yes, it’s the one that looks for the information needed to respond to DNS queries from users.

It’s an essential and efficient part of the DNS system. Recursive is derived from the word recursion. In computing, a solution or a specific process will repeat as many times as necessary to achieve a goal. And that description closely resembles how a Recursive DNS server works.

When a user requests a domain using a browser, a DNS resolver is the first stage to find the domain’s corresponding IP address. It can be quick and straightforward to obtain or require additional steps and effort. On the other hand, the server will not stop looking for it until it finds it. Then it will deliver it to the browser, which will then load and access the asked domain for the visitor (device).

How does Recursive DNS server work?

The recursive DNS server has two modes of operation. They are the following:

The first way is thought to be much simpler and speedier. The Internet address(IP) is stored in its cache memory. These servers can save the information in their cache for a specific period of time. It is up to the administrators to decide how long they should keep it. They can use the time-to-live (TTL) to evaluate whether they need more or less time. Actually, it’s all reliant on the administrators’ plan.

When the recursive DNS server receives the query, it will first look for the IP address in its cache memory. The assignment is complete if that information is still available there and the TTL has not yet expired. It’s advantageous since the answer is quick, and the recursive DNS server doesn’t have to look for information on other servers.

The second way of the search will take a little longer to finish. It occurs when the cache’s TTL has passed its expiration date. As a result, the IP address is no longer accessible. On the other hand, the recursive DNS server goes a long way toward obtaining the needed information. It travels from the root server to the TLD (Top-Level-Domain) server to the authoritative server, which is the one that can answer the question.


In conclusion, we can say that recursive DNS servers are essential for making the resolution process and the Internet, in general, more flexible. As a result, their numbers are significant, and their presence is widespread. Recursive servers are used by every Internet Service Provider (ISP), and they aren’t just for ISPs. DNS service providers, domain registrars, and various network providers are all examples of DNS service providers.

What is the purpose of the Authoritative DNS server?

What is an Authoritative DNS server?

An authoritative DNS server (also known as an authoritative nameserver) holds the zone file containing DNS records (for A, AAAA, CNAME, TXT, etc.). It could be a domain registrar or a DNS hosting provider’s server.

Several authoritative servers cover various locations. They only respond to queries for the DNS zones they have set up.

They have two primary missions in general. The first is to keep track of domain names and their IP addresses in a database. The second objective is to respond to recursive DNS servers by supplying the correct IP address for each user’s domain.

An authoritative server does not save any cache query results. Instead, it works with original data that has been saved directly in its system.

How to check it? 

The Nslookup command, which is available on Windows, macOS, and Linux, is the simplest way to check the authoritative DNS servers.

To begin, Open the Command Prompt on Windows or the Terminal on macOS and Linux. And after that, run the Nslookup command:

nslookup -type=ns

You will see a list of the domain’s nameservers as well as their IP addresses. It looks like this: 



Non-authoritative answer: nameserver = nameserver =

* You can replace “” for the domain name you want to test.

Different types of Authoritative DNS servers

Primary and secondary authoritative DNS servers are the two types of authoritative DNS servers. But, first, let’s have a look at the distinctions between them.

  • Primary or Master Authoritative DNS server stores the zone file and DNS records. It is the only server that allows DNS record changes. As a result, the primary server must notify and provide updates containing all changes made to its zone file. So, it includes a “notify” feature in its functionality. It allows a primary server to notify a secondary server of a new update so that the latter can request it. We use the zone transfer to distribute an update to all secondary servers.
  • Secondary DNS server, also known as a Slave DNS server is a copy of the primary server that cannot be edited. Redundancy is essential and always welcome to avoid risking critical processes and information. Having a secondary server means having a useful backup as well as other benefits. The traffic load can be distributed among servers using these copies to avoid stress. The more nameservers you have to respond to DNS requests, the faster you can serve traffic. Secondary servers are transformed into points of presence (PoPs) where recursive servers can locate the information that users all over the world require.

Authoritative DNS server vs. Recursive DNS server

Imagine the following situation – you are trying to connect to a website ( This query will pass through authoritative and recursive DNS servers, also known as DNS resolvers. They respond to the request and store the canonical information that tells you which IP address corresponds to that domain. For example, the domain fits to Internet Protocol

So, we can say that the recursive DNS servers communicate directly with the end-user, while authoritative DNS servers authority DNS records and maintain DNS record information. This is the main difference between them. In addition, the recursive DNS server reads a user’s DNS request and responds with cached data or finds the answer before responding. So, DNS resolvers can get the answer by looking at what is stored on the authoritative DNS servers.

Primary DNS zone vs. Secondary DNS zone

The comparison Primary DNS zone vs Secondary DNS zone often raises questions in the inexperienced and those just entering in the Domain Name System world. Can we use only the Primary DNS zone, or do we need to implement the Secondary DNS zone? Today in our article, we will take a detailed look at these zone types and how they function. So, let’s bring it on.

What exactly is a DNS zone?

The DNS server you’re using can handle many zones to manage the DNS namespace better. The DNS zone is a part of the domain namespace. In most cases, DNS or web hosting companies delegate it, which are responsible for managing the DNS. A DNS zone is also an administrative function, it allows control over the most important DNS components, such as the authoritative name servers.

It would be best to direct your domain to numerous servers, such as web servers, mail servers, and so on, to function effectively. You can do it by adding different DNS records to the DNS zone.

The DNS zone is the storage location for all DNS records. It is also the only component accountable for the Domain Name System’s existence (DNS). Furthermore, the DNS zone contains information about DNS records and administrative contact information for the DNS zone and zone parameters.

A DNS zone, for example, can be relevant for .uk,, and so on. However, examining a subdomain as a standalone website will necessitate dedicated administration. As a result, the subdomain will require its zone.

What is the definition of the Primary DNS Zone?

A Master DNS Zone is another name for the Primary DNS Zone. You have control over that specific area of the namespace. There, you can remove and add DNS records and manage your domain name to your preference. If you’re going to administer the domain, every component of it, that is, every host you want to manage, might be a separate Primary DNS Zone. In addition, a domain name can only have one Primary DNS Zone.

The Primary DNS zone is a DNS administrative unit that allows authority over the section (zone) permitted by the DNS hierarchy’s higher levels. 

What does a Secondary DNS zone mean?

The DNS Secondary Zone is a read-only copy of the primary (Master) DNS zone records. It is also known as the Backup DNS zone or the Slave DNS zone. It is critical to understand that DNS records such as A or AAAA, MX, and others cannot be directly added to the Secondary DNS zone. The only way for the records you’ve refreshed to reach your Backup zone is through а transfer from the Primary DNS server/s  (Master DNS zone).  So, if you need to keep your DNS records in the Backup zone up to date, you must first update them on your primary server.

Primary DNS zone vs Secondary DNS zone – the difference

You may be a little confused about what exactly is the difference between these two areas, as they contain the same thing from what has been explained above. Yes, they do. But in fact, the Backup DNS zone cannot exist on its own. The only significant distinction is how the resources are stored on the server. The original zone files are kept in the primary, while a copy is in the secondary. That is, updates to record configurations appear differently.

Get familiar with FQDN

What does FQDN mean? 

Fully Qualified Domain Name is more commonly known as its short acronym FQDN. Its main purpose is to show specifically the most complete version of the name of a particular domain name. In addition, that could be related to a website or to a server. 

The Domain Name System (DNS) is decentralized, and it has a very precise hierarchical order. The beginning and above everything else is the Root, and a level below is the Top-Level Domain (TLD). Next in the hierarchical order is the domain, and lastly is the precise hostname.

To make things a little bit more simple, here is an illustration of the full syntax of a Fully Qualified Domain Name (FQDN):

hostname. domain name. TLD 


Take note that oftentimes the dot “.” that is last is frequently neglected by regular users. It specifies the Root. However, it is not required when you are surfing the Internet on an everyday basis. There are only several cases when you are going to need it

Elements and Structure of FQDN

The Fully Qualified Domain Name (FQDN) actually has a very simple structure and three main elements. So, let’s explain a little bit more about them:

TLD (Top-Level Domain): It is illustrated with all of the familiar extensions that take place at the very end in an FQDN. Typically they are very short, and their length is only 2 or 3 letters, for instance, .com, .edu, .uk, etc. Of course, there are TLDs that are a little bit longer than that, such as .systems, .company, etc.

Domain: It is one level below the Top Level Domain (TLD) and is very familiar to everyday users. For illustration,

Hostname: It is easily defined with the symbols at the very beginning of the Fully Qualified Domain Name (FQDN). A very common and popular example is www in Depending on the need of the domain owner, he or she could make separate hostnames, and they are going to be connected to the domain. Here are some examples of such different hostnames:


Why do you need it?

There are so many different addresses on the Internet, and thanks to the FQDN, it is possible to describe the uniqueness of each of them. Therefore, it is crucial for a great online experience. Just imagine if there is no FQDN, your website is going to be hard to reach.

It is necessary to install an SSL certificate. This is because the majority of the websites are expected and required to have a feature like that.

Thanks to it, you have the ability to access domain services, such as File Transfer Protocol (FTP) and email. You are going to need it also if you desire to connect a domain name email to an email app

What does PQDN mean?

A Fully Qualified Domain Name with a missing part is also known as a Partially Qualified Domain Name (PQDN). If there is a missing element, it won’t show the precise location on the DNS hierarchy. For illustration, is a PQDN because it is missing the web host (www.) before the domain name. Regular users are used to typing only the PQDN because it is easier for them.

List with most popular Managed DNS service providers

A DNS service assists with handling the Domain Name System (DNS) servers. You could find various types of DNS service such as Managed DNS service, Dynamic DNS, Reverse DNS, Secondary DNS, Anycast DNS, etc. Additionally, you could be sure that a DNS service is a great choice when the DNS provider maintains many servers in different geographic areas. That way, it supplies stability and minimizes latency for its customers worldwide. DNS queries travel less, which boosts the speed of DNS resolution. Here are some of the most popular Managed DNS service providers!


Namecheap offers some very useful DNS hosting services featuring Dynamic DNS. They also provide Free DNS for small organizations, plus a free DNS management feature. It also offers features like email forwarding, URL forwarding and supports various DNS records, including A, AAAA, CNAME, SRV, and many more. 

Namecheap has multiple reliable name servers spread globally. Additionally, they help with improving the speed and performance of your website. They supply their customers with an easy-to-use console for DNS management for the complete administration of their clients’ DNS settings. 


ClouDNS is one of the very solid Managed DNS service providers that offers excellent DNS services and a fantastic price-performance ratio. It holds 34 Anycast locations placed all around the world. Many big brands, such as SpaceX, Starlink, TikTok, and Kia, trust ClouDNS to provide them with their services.

In addition, it has a Free DNS plan for smaller businesses with pretty decent features. The collection of DNS records supported by ClouDNS contains pretty much each basic DNS record plus some which are more on the advanced side.

It also provides fantastic Dynamic DNS, GeoDNS and DDoS protected DNS with a guarantee of 100% uptime and 24/7 customer support.

DNS Made Easy

DNS Made Easy is another one of the Managed DNS hosting providers that provides great speed to their clients. In addition, its Premium DNS plans are considered very affordable and offer a lot of great features. Of course, the basic plan is a great opportunity for small or mid-level organizations.

In addition, a fantastic feature that they supply is two-factor authentication. Thanks to it, it is possible to prevent somebody from hijacking a domain name and redirecting all of the available DNS records to a fraudulent place. DNS Made Easy offers the two-factor authentication feature contained in every single plan they have.

They give to their clients a pretty pleasant 30-day free period to test their services. That way, clients are able to determine if DNS Made Easy is working best for their website.

Hurricane Electric Internet Services

Hurricane Electric Internet Services offers DNS hosting service for free. They deliver their customers a solid connection all over the globe. Hurricane Electric IS holds an extensive network with many Points of Presence (PoPs) that not only supports IPv4 but also IPv6 in every place.

That DNS hosting provider gives the opportunity for establishing a low time-to-live (TTL) value which is not so common in many other free providers. Moreover, it has a collection of very useful DNS management features.

The tiny disadvantage is probably the interface, which is considered a bit aged and slightly not on the most trendy side when it comes to web design. Yet, it is a reliable DNS provider that numerous website owners trust completely.