Tag: Top-Level Domain

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 example4domain.org 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.

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, website.com.

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 www.website.com. 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:

  • www.website.com
  • ftp.website.com
  • mail.website.com

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, website.com 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.