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All you need to know about DNS protocol

563 Views | 19 hours ago | Published On: August 04,2021 - Last Updated: February 29,2024

DNS protocol

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All you need to know about DNS protocol

The internet comprises millions of devices, not limited to computers but also smartphones, servers, and all smart devices, in addition to 1.7 billion websites. The global internet results from the interconnection of all these devices, servers, and sites. Anyone can visit any website and access its content by simply typing that site's domain name into their personal device's browser. But here comes an important question, how is that possible? This article will answer that question.



Information about DNS protocol
What is the DNS protocol

Websites rely on unique addresses similar to phone numbers. Each website has its own address that distinguishes it from other sites, which are called Internet Protocol (IP) addresses. IP addresses are not limited to websites, but every electronic device, whether a phone, computer or any smart device, has a unique IP address.

An IP address consists of a series of numbers, and due to the enormous number of IP addresses, it has become difficult to remember those addresses in the form of numbers. The DNS protocol began to be used to make it easier for users.

It is clear that there is a server behind every website, and the actual address of this server is not the domain name but its specific IP address. DNS stands for Domain Name System and is a directory for domain names and their corresponding IP addresses. The browser can retrieve the website's content using the correct IP address. The role of DNS is crucial here, as before your browser requests the content, it first requests information about where to get the required information.

In fact, the DNS protocol is more than just a big server with a list of all domain names. Its internal structure is much more complex, consisting of several essential components and servers of various types, each of which deserves a separate explanation.

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How the DNS protocol works

The Domain Name System (DNS) is an integral part of the internet, and it is essential to understand how it works. Think of the DNS as a phone directory, as we mentioned before. Still, instead of assigning people's names to their street addresses, the phone directory gives computer names to IP addresses. Each assignment is called a "domain name system record."

The internet has a lot of computers, so it is practical to put only some of the records in one big book. Instead, the DNS protocol is organized into smaller books or domains, if you will. IP addresses can be extensive, so they are collected into even bigger books called "domains." Each DNS server stores only some IP addresses - that would be impractical.

Instead, many DNS servers store all DNS records for the internet. Any computer that wants to know a number or name can ask its own DNS server, and the DNS server knows how to query - or ask - other DNS servers when it needs a record.

A DNS server performs a "primary" query when it queries other DNS servers. Domain-specific questions can be passed to the "source" until they return to the domain authority or "authorized name server."

Administrators manage server names and IP addresses for their domains in the authorized name server. When DNS administrators want to add, change, or delete a server name or IP address, they change the authoritative DNS server (sometimes called the "primary DNS server"). There are also "subordinate" DNS servers; these DNS servers retain copies of DNS records for their zones and domains.

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DNS Root Server

Let's say the browser receives a request to find the IP address for the website "alalmiyalhura.com." There is no data in the cache memory, so the task begins by calling the root name server (DNS Root Server). The root server is responsible for providing information about DNS servers for any top-level domain, such as ".net," ".com," ".org," etc.

This means the root server cannot answer with an IP address corresponding to "alalmiyalhura.com," but it can undoubtedly respond with a list of servers responsible for serving a specific top-level domain TLD.

There are about 750 root servers worldwide, and it is available from 13 primary and permanent known IP addresses for each repeater. The next step can be taken and called by obtaining information about the TLD server.

Top Level Domain (TLD) Name Server

Similar to the root server, but at the global level, a Top Level Domain (TLD) name server knows information about the servers responsible for any domain at a certain TLD level. For example, the resolver, in our case, will ask the (.com) TLD server for the address of the authoritative server for the "alalmiyalhura.com" domain.


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TLD top-level domain name server

Similar to the root server, but at the global level, a Top Level Domain (TLD) name server knows information about the servers responsible for any domain at a certain TLD level. For example, the resolver, in our case, will ask the (.com) TLD server for the address of the authoritative server for the "alalmiyalhura.com" domain.

Authoritative Name Server

This type of name server is usually the last step in the lookup process. It is called "trusted" because it always provides only basic, non-cached information regarding the domain it is responsible for. In our example, the authoritative server for the "alalmiyalhura.com" domain will respond with the relevant data, and finally, the resolver will react to the browser with individual or multiple IP addresses. These addresses should be used to establish a connection to fetch the website content.


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