This article will share the relevant content about the need to understand the DNS server in use. Objectively, DNS stands for Domain Name System, which refers to the set of elements that map domain names to IP addresses. What are the main functions of a DNS server?

The so-called DNS network is made up of all DNS servers. The DNS network allows users to more easily access the Internet and related services such as websites, online messaging services, etc. You can allow users to access the website by domain name, do not need to access through the website's server IP address.

There are four types of DNS servers, DNS resolvers (or recursive DNS), root DNS servers, Extended/top-level domain name (TLD DNS) DNS servers, and authoritative DNS.

A DNS resolver, or recursive DNS, refers to the first server to receive DNS requests from clients (web browsers, email software, etc.). This server acts as both a client and a DNS server, knowing to retrieve the IP address requested by the DNS request from the reference DNS server. The client sends a DNS query to find the IP address of the domain domain.tld. For example, the Web browser sends a DNS query to the IP address of the domain name domain.tld. This will show you the server that hosts the website associated with the domain domain.tld.

The root DNS server contains the directory of all TLDS, such as.com,.net, and.uk. Notifies the DNS resolver of the address of the DNS TLD server corresponding to the extension present in the DNS query requested by the client. For example, the DNS resolver forwards the DNS query received for domain.tld to the root DNS server and receives the address of the DNS TLD server with the.tld extension as a response.

DNS server for extended/top-level domain names (TLD DNS). Contains the domain name directory for the given extension. It will inform the DNS resolver of the reference DNS server address corresponding to the domain name present in the DNS query requested by the client. For example, the DNS resolver forwards the DNS query received for domain.tld to the TLD DNS server with the extension in the management.tld, and receives the address of the reference DNS server for the DNS zone that manages the domain domain.tld as a response.

Authoritative DNS, the last DNS server queried by the DNS resolver, the active DNS zone containing the domain name present in the DNS query requested by the customer, and then, The DNS resolver forwards DNS requests received for domain.tld to the authoritative DNS server that administers the DNS zone of the domain domain.tld, and as a response receives the IP address of the server that hosts the website hosting the domain domain.tld.

Once the DNS resolver retrieves the client's requested DNS request search server IP address, it returns that IP address to the client. The client sends another request directly to the server associated with the IP address retrieved using DNS resolution, so that the machine can connect to that server or retrieve the elements needed to resolve the second request.

The DNS server (authority) contains a directory of domain names that can have different extensions (TLDS).

For each domain name in the directory, there is a DNS zone associated with it that contains the DNS configuration to be applied to that domain name. DNS zones contain technical information called DNS records. Therefore, a DNS server (authority) must be registered (with the domain name registrar) to use the DNS zone it hosts.