What is a DNS server?
A DNS (domain name system) server, also known as a DNS name server, is a computer system that acts as a translator between humans and computers. It resolves human-readable domain names (like “www.example.com”) into IP addresses (like “192.0.2.1”) that enable computers to locate and communicate with the correct web servers hosting a website.
This resolution is part of the DNS, a global network that keeps track of domain names and their corresponding IPs. The DNS functions just like the internet’s address book, and DNS servers are the tools that retrieve the correct IP address. Without DNS name servers, users would need to remember different strings of numbers to access their favorite websites, making the internet far less user-friendly.
How do the DNS servers work?
The primary job of a DNS server is to resolve domain names into IPs so that web browsers can locate and load the desired web pages. This process, known as a DNS lookup, begins the moment you type a URL into the address bar of your browser:
- 1.You enter the domain name into a browser’s URL bar, like “www.nordvpn.com.”
- 2.The browser first checks its local cache to see if it has the corresponding IP address stored from a previous visit. If it finds the IP address, it skips further steps and connects directly to the website.
- 3.If the browser doesn’t have the IP address information cached, it sends a query to the local DNS resolver (stub resolver) built into the OS to find which network or IP address the domain name belongs to.
- 4.The operating system’s DNS stub resolver forwards the query to a recursive DNS resolver, typically provided by your ISP or a third-party DNS provider.
- 5.A DNS resolver (also known as a DNS recursor or recursive resolver) receives the DNS query and first checks its own DNS cache for the address.
- 6.If the resolver does not already have the information cached from previous queries, it continues the lookup process by contacting a root name server. This server doesn’t provide the IP address itself but acts as a directory, directing the recursive resolver to the appropriate top-level domain (TLD) name server based on the domain’s extension (like “.com,” “.org,” or “.net”).
- 7.The resolver contacts the TLD name server, further narrowing the search by pointing to the authoritative name server responsible for the specific domain.
- 8.The authoritative name server hosts the exact domain IP details. It provides the recursive resolver with the correct IP address needed to locate the website.
- 9.The DNS resolver then sends the IP address back to your browser. The browser uses this information to connect to the web server hosting the website, allowing the page to load on your screen.
To speed up future lookups, the recursive resolver caches the retrieved IP address for a specific time period. This time is determined by the DNS TTL (time to live), which specifies how long the cached DNS record is valid. This way, if the same domain name is requested again, the resolver can skip the entire lookup process and provide the IP address directly from its cache. Once the TTL expires, the DNS resolver will have to perform a fresh query to get the updated IP address.
While the process involves multiple servers and several steps, DNS lookups happen incredibly fast, often within milliseconds. This speed ensures a smooth browsing experience with minimal delays when accessing websites.
Types of DNS servers
Several types of DNS servers are involved in the process of translating domain names into IP addresses, but they don’t all perform the same role. Let’s take a closer look at the four types of DNS servers and how they contribute to resolving DNS queries.
Recursive DNS server
A recursive domain name server, or DNS resolver, is the first stop in the DNS lookup process. It reacts and responds to DNS queries and can track down the records needed to find the correct root server. The recursive DNS server acts as an intermediary, managing the entire process of querying multiple other servers (such as root, TLD, and authoritative name servers) and retrieving the final IP address before returning it to the client’s browser.
Root name server
When a recursive server doesn’t have the requested IP address in its cache, it forwards the query to a root name server. The root server doesn’t provide the final IP address but serves as a directory, responding with a referral to the appropriate TLD name server by using the domain name extension (like “.com,” “.net,” or “.org”). Thirteen root server clusters have been distributed worldwide to ensure fast and reliable responses.
Top-level domain (TLD) name server
TLD servers are responsible for managing domain names (the part after the last dot in the URL) under a specific top-level domain (TLD), such as “.com,” “.org,” “.net,” or country-code TLDs like “.uk” or “.de." After receiving a query from a root name server, the TLD server directs the request to the authoritative DNS name server that holds the exact domain information. For example, a query for “www.example.org” would be forwarded from the root server to the “.org” TLD name server, which would then forward it to the authoritative server.
Authoritative name server
An authoritative DNS server is always the final step in the DNS resolution process. It contains the official DNS records for a domain, including A records (IPv4), AAAA records (IPv6), CNAME records (aliases), MX records (mail servers), and others, which map domain names to their respective IP addresses. When an authoritative DNS server receives a DNS request, it doesn’t need to query other servers. It directly provides the requested IP address to the DNS resolver.
How to choose a DNS server
While your ISP typically assigns you its default DNS servers automatically when you connect to the internet, they may not be ideal. After all, the DNS server can have a big impact on your browsing experience. Here’s what factors you should keep in mind when making your choice:
- Speed. Nobody likes slow-loading websites, so speed is definitely an important factor when choosing a DNS server. A fast DNS name server can significantly reduce the time it takes websites to load by speeding up domain name resolution.
- Security. Security should always be a top priority, so look for DNS servers with strong security features. Some DNS services offer DNSSEC (domain name system security extensions), which help protect against unauthorized DNS data modifications. This way, you can be sure you’re connecting to the legitimate websites you intended.
- Privacy. Privacy is a big concern when choosing a DNS server. Some DNS services handle your data differently — some may log your DNS queries, while others don’t. Always check the privacy policy to see how your data is treated.
- Additional features. Some DNS providers offer added features such as ad-blocking or malicious domain blocking. If you’re looking for more control or want to block unwanted ads or harmful sites, these features can make a significant difference.
How to change your DNS server
Changing your current DNS server can significantly improve your internet experience if you’re looking for better speed and a safer internet connection. To do so, follow a few simple instructions:
- 1.Find the magnifying glass icon at the bottom of your computer screen and click on it.
- 2.When a window with a search bar appears, type in “Manage network adapter settings” and open the matching result.
- 3.Find either “Ethernet” or “Wi-Fi,” depending on which one you are using, and click on it. More details will appear, including the option to “View additional properties.” Click it.
- 4.Next to “DNS server assignment,” press the “Edit” button.
- 5.In the small pop-up box, select “Manual.”
- 6.Now, adjust the settings as follows:
- “IPv4” turned “On.”
- Preferred DNS: [type in the primary DNS address]
- Alternate DNS: [type in the secondary DNS address]
- “IPv6” turned “Off.”
- 7.Click “Save.” And you’re done!
If you’re not a Windows user, you can find a full guide on how to change the DNS of all devices. In addition, NordVPN DNS servers can be automatically configured on your devices to prevent potential DNS leaks.
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