The Domain Name System (DNS) acts as the internet’s directory. It translates human-readable domain names into computer-friendly IP addresses — like an interpreter bridging two languages. When you enter a domain name into your browser, DNS looks up the corresponding IP address so your device knows where to connect.

Think of DNS servers like the backstage crew of a play. They work quietly behind the scenes, handling critical tasks that make everything run smoothly: routing requests, resolving domain names, and connecting users to websites and internet-based services. Just as slow scene changes can disrupt the flow of a performance, slow DNS responses can delay website loading times. If DNS servers are down or overloaded, users may experience timeouts or failed connections — impacting the overall browsing experience.

In this guide, we discuss the ins and outs of DNS servers, including the types and common issues. We also explain why a DNS server is essential for businesses and individuals. 

How DNS Servers Work

Every internet-connected device has a unique IP address that allows other devices to locate it. These IP addresses are a long series of numbers. DNS servers allow people to type human-friendly words into a browser, such as “noip.com,” instead of remembering a website’s IP address (158.247.7.200). DNS allows domains to be more functional and customized for a better user experience.

Once an IP address is located, browsers use it to communicate with origin servers to access a website’s information. DNS servers make this translation process seamless. They also allow websites to accommodate high traffic and dynamic IPs, which results in increased uptime and faster load times.

The Translation Process

Translating a user-friendly domain into a machine-friendly IP is called DNS resolution. This multi-step process takes a fraction of a second and includes the following steps:

1. 1.You type a domain name into a browser.
2. 2.The browser sends a message, known as a recursive DNS query, to the network. 
3. 3.The query is sent to a recursive DNS server, or a recursive resolver, usually managed by your internet service provider (ISP).
4. 4.If another device has used the same recursive server to look up the domain before, the server may already have the information cached. If the recursive resolver knows the answer to the DNS query it will translate the domain into numbers (an IP address), and your webpage will load. 
5. 5.If the recursive server doesn’t know the answer to the dns query, it passes your request to other servers. These servers include DNS root name servers, top-level domain (TLD) name servers, and authoritative name servers.
6. 6.These servers cooperate and redirect your query until they find a DNS record with the appropriate IP. When your requested IP is found, they send the information to the recursive DNS server, which allows the webpage to load. 
7. 7.Once a recursive server receives the information, it stores the address (A) record for the domain name. The next time someone searches for the same domain name, this server pulls up the cached record and finds the IP.This means future requests won’t take as long, as the route is already known by the server.
8. 8.If the authoritative server can’t find the IP information for your domain, you’ll receive an error message. 

Types of DNS Servers

As outlined above, there are two  main types of DNS servers: recursive and authoritative. The top level and root servers are part of authoritative.. Each one has a specific purpose. Once you understand the role of each DNS server type, you’ll have a much better understanding of DNS servers overall!

Recursive DNS Servers

The recursive DNS server, also known as a resolver, is the first stop in the DNS lookup process. When you enter a domain name, the resolver receives the query and checks its cache to see if it already has the corresponding IP address. If the information is cached, it returns the result immediately. If not, the resolver forwards the query to the appropriate nameservers to continue the search and retrieve the correct IP address.

After the recursive server receives information from the name server, it loads the data . The server then stores that information for a while, which allows the page to load faster in the future. Most of these types of DNS servers are provided by ISPs (“Internet Service Providers,” like Xfinity or Spectrum).

Authoritative DNS Servers

Authoritative DNS servers are usually the final stop in the DNS resolution process. These servers hold the published DNS records for a specific domain — the ultimate source of truth. 

Two types of authoritative DNS servers play a vital role in the DNS lookup process: root nameservers and top-level domain (TLD) nameservers. When a recursive DNS server doesn’t have an answer cached, it sends the query to a root nameserver, which identifies the extension of the domain — such as .com, .org, or .edu — and directs the query to the appropriate TLD nameserver.

Each TLD has its own set of designated nameservers. For example, if you’re trying to access a .edu website, the query will be routed to one of the .edu TLD servers. From there, the TLD server points the request to the authoritative nameserver, which holds the actual DNS records for the domain and provides the final IP address needed to load the site.

Once the authoritative server provides the answer, the information is sent back through the recursive resolver, allowing your browser to connect to the correct web server and load the site.

Common Issues With DNS Servers

As with any system, DNS servers can run into problems. The most common issues include: 

• DNS resolution failure: This occurs when a DNS server cannot match an IP address to a domain name. Incorrect domain configuration, unregistered domains,and network connectivity issues can cause resolution failures. 
• DNS server not responding: This error usually occurs when a DNS server is down or it isn’t set up correctly. Incorrect DNS configuration: If a domain has a dynamic IP, its DNS record may have outdated information. When you search for a website, the DNS server can’t translate your query, or the IP address no longer points to the right place. 
• High latency and propagation: DNS latency measures how long a query takes to travel through the translation process. If a webpage (or a DNS server) has a high latency, it loads slower. Too many people using the same server or insufficient DNS infrastructure can impact your propagation time.

Security Issues

Cyberattacks are a risk with any IT system, and DNS servers are no exception. These attacks can overwhelm servers with traffic, take down infrastructure, and cause websites to be inaccessible. Common types of DNS attacks include the following:

• Flood Attacks: Distributed denial of service (DDoS) attacks flood authoritative name servers and overwhelm them. The influx of traffic renders them unable to fulfill DNS queries.
• Random subdomain attack: This DDoS attack sends requests for fake subdomains to authoritative servers. 
• Cache poisoning: Forged DNS data sneaks into a recursive server’s cache. This infiltrator assigns a different IP address for a domain, bringing unwitting internet users to the wrong website, usually resulting in a phishing attempt. 
• DNS hijacking: This attack gains unauthorized access to DNS server management systems. After receiving access, the attack changes or destroys data. 

Why Use No-IP for Your DNS Server?

Having reliable and secure access to a DNS server is essential for a seamless browsing experience. At No-IP, our managed DNS provides you with a high-performing, globally distributed network that reduces your downtime. Our global Anycast network uses innovative security features, like SSL and two-factor authentication, to prevent attacks and keep your data secure. Additionally, our solutions scale with you as your needs change. 

Whether you’re an individual looking for secure remote access to your home network or a business looking for expert-backed infrastructure, No-IP has a solution for you. Our dynamic DNS (DDNS) service helps ensure your DNS record is updated when your IP changes. By keeping your directory listing updated, you can reliably access your network or domain with no downtime. Contact us today to further explore our offerings.