DNS or the Domain Name Server is an integral part of systems’ connection and communication on the internet. Without a Domain name system, the people and computers would only connect using numerical addresses known as IP addresses. This guide will discuss “what are the different types of DNS servers?” and what the features of each one are.
DNS Server and its Function
Before starting today’s subject, let us briefly define what a DNS server is. DNS servers are computer servers that contain a specific database of public IP addresses and their related hostnames. Generally, DNS servers serve to resolve/translate the names to IP addresses as they are requested. DNS servers run unique software and communicate with each other based on unique protocols. DNS servers can be referred to as name servers, nameservers, and domain name system servers.
The Purpose of DNS servers
It is much easier to remember a domain or hostname like ArvanCloud.com than to remember its IP address numbers. With a DNS server implemented, all the users must do when they access a website is to type the URL, https://www.arvancloud.com. Since computers and network devices are not good with using domain names while locating each other on the internet, it is more efficient to use an IP address which is the numerical representation of what server on the internet the website resides on. DNS servers stand between humans and computers to help facilitate their communication.
DNS Servers and Resolving a DNS Query
Prior to answering “What are the different types of DNS servers?” it is essential to know how a DNS server resolves a DNS query. In our article What Is DNS? How Does DNS Work? We talked about DNS functions in detail. To highlight the gist, when users type a website address into a browser address bar and press Enter, a DNS server will find the searched address. It is done by sending a DNS query to several servers, each of them will translate a different part of the domain name entered. Here are other servers queried:
A DNS Resolver will receive the request to resolve a domain name with the IP address; it will determine where the intended site resides on the internet.
A Root Server will receive the first request, then return a result to let the DNS resolver know the Top-Level Domain (TLD) server’s specific address, which stores the data about the site. A top-level domain is like .com or .net part of the domain names users enter in the address bar.
TLD Server will be queried by the DNS resolver. It will return the Authoritative Name Server where the site is retired.
An Authoritative Name Server will be queried by the DNS resolver to learn the entered website’s actual IP address.
Once the correct IP address is returned, the intended website will be displayed in the web browser. This process happens very quickly with little delay to return the site users want to visit. Besides the above-mentioned main servers, a DNS query may involve some other DNS servers, which will be explained.
What are the different types of DNS servers?
The Domain Name System employs various servers at different points. In a DNS lookup, mainly four DNS servers work together to complete the purpose of delivering the IP address for an intended domain. DNS servers are responsible for a variety of roles that are controlled by their configuration file. The name server’s complete function is determined by the combination of global factors in the configuration file and the serviced zones.
DNS root servers are responsible for TLD. they are located at the top of the DNS hierarchy and maintain data about TLD zones. It is the central interface between users and content on the internet, and it will link domain and IP addresses. ICANN (Internet Corporation for Assigned Names and Numbers) coordinates the function of the root name server.
Authoritative Name Server
An authoritative name server is responsible for a specific zone, and they answer queries from their area of authority with binding detail. If the authoritative name server is unable to respond, the root name server will take over.
There is only one primary server per domain, and each domain must have one. Primary servers are where all the changes are made to the domain; they are authoritative for their served domains. They update and synchronize secondary servers.
Secondary servers obtain a copy of the domain data for all domains they serve from the primary server or other secondary servers of the domain. They are authoritative for their served domains. They receive updates from primary servers. They provide load sharing for all the servers of the domain. If other servers are unavailable, they provide redundancy. They can provide more local access to name resolution.
Non-authoritative Name Servers
Non-authoritative servers are not responsible for a specific DNS zone. They collect data on specific zones by recursive or iterative DNS queries.
Caching servers store the information from other name servers for specific periods of time determined by the authoritative name server. They provide a local cache of looked-up names. They are not authoritative for any domain. They have lower administrative overhead. They reduce the overhead related to the secondary server’s zone.
Forwarding servers forward queries to another DNS server. They are a focal point for all off-site DNS queries. They centralized off-site requests. Off-site queries will go through forwarding servers first. They will reduce the number of redundant off-site requests. Forwarding servers need no special setup.
Resolver servers are not authoritative DNS servers, but they can perform name resolution locally in the router or computer.
About ArvanCloud Managed DNS Service
ArvanCloud managed DNS service will offer you a professional team, 24/7 support, and many excellent features for a reliable, efficient, and scalable DNS infrastructure. As a world-known authoritative DNS service, we will provide you with the fastest response time and super-advanced cloud security (like DDoS mitigation and DNSSEC). To know more about managed DNS you can also read our article: What Is Managed DNS?.