DNS Server: What Is It, and Why Is It Needed?

Domain Name System (DNS) is a specially created Internet technology, the main task of which is to turn the name of a website into an IP address for users to access it through web browsers. DNS servers, by their very essence, resemble a phone book, where each name corresponds to the number to which the call is made. Only in this case does the name correspond to the IP address. Use DNS to speed up the connection to the target resource.

Video: How to Configure DNS Settings on Windows, Mac OS, Router

What is a DNS Server: Definition and Functionality

A DNS server is a specialized computer that holds a large database mapping domain names to IP addresses. This mapping lets you use easy-to-remember domain names like example.com instead of numeric IP addresses like 93.184.216.34. When you type a URL into your browser, the DNS server helps find the correct IP address so your device can connect to the website.

The process of finding an IP address is called DNS resolution. It involves different types of queries: recursive and iterative.

• In recursive queries, your local DNS resolver asks other DNS servers on your behalf until it finds the answer.
• In iterative queries, each server provides the best answer it can, and your resolver asks the next server.

The process starts with root servers, which direct queries to top-level domain (TLD) servers like .com or .org. TLD servers then point to authoritative name servers, which hold the exact IP address for the domain.

Here’s a typical DNS request in action:

1. You enter a URL in your browser.
2. Your device asks the recursive resolver for the IP address.
3. The resolver queries root servers, then TLD servers, then the authoritative server.
4. The authoritative server responds with the IP address.
5. The resolver returns the IP to your device.
6. Your browser connects to the website’s server using the IP.

Core Types of DNS Servers

There are several types of DNS servers involved:

• Recursive resolver: Your local server that starts the DNS query chain.
• Authoritative name server: Holds definitive DNS records for domains.
• Root server: The highest-level server that points to TLD servers.
• Forwarder: Helps route DNS requests to other DNS servers, often for caching or filtering.

DNS queries use UDP on port 53 for speed. If the response is too large or for specific tasks like zone transfers, the query falls back to TCP.

DNS servers use caching to store responses temporarily, reducing repeated queries and speeding up future lookups. Each DNS record has a Time-To-Live (TTL) value that tells the cache how long to keep the data before fetching fresh information. When TTL expires, the cache invalidates the record and asks authoritative servers again. Caching minimizes latency and reduces load on authoritative servers.

Understanding this process helps you troubleshoot issues like how to fix DNS server not responding errors and learn how to change DNS server settings for better performance or security.

How DNS Works

The moment you enter the name of the site in the address bar, the web browser contacts the nearest DNS server to match the name you specified with the IP address and then connects to it. The problem is that not all DNS servers contain information about all names and their IPs.

If the name you specified is not in the database, then the request is redirected to another DNS server, which makes the connection time longer. DNS servers of such companies as Google (8.8.8.8.8 / 8.8.4.4) with huge databases that many users register instead of those provided by their provider help to fight this problem.

Types of DNS Records and Their Management

DNS records are key instructions stored on DNS servers. Each type has a specific role that keeps the internet running smoothly.

Here’s a practical list to help you understand common DNS record types, their purpose, and examples:

• A record: Maps a domain to an IPv4 address (e.g., example.com → 93.184.216.34).
• AAAA record: Maps a domain to an IPv6 address (e.g., example.com → 2606:2800:220:1:248:1893:25c8:1946).
• CNAME record: Creates an alias from one domain to another (e.g., www.example.com → example.com).
• PTR record: Used for reverse DNS lookup, mapping IP addresses back to hostnames.
• NS record: Specifies the name servers responsible for a domain.
• MX record: Lists mail exchange servers for handling email, with priority values.
• SOA record: Start of Authority; contains primary zone control details like serial number, refresh, retry, and expiration times.
• TXT record: Stores text data for verification and policies, such as SPF records for email validation and domain ownership proofs.
• CAA record: Defines which certificate authorities can issue SSL certificates for the domain.
• SRV record: Locates services by specifying ports and protocols (e.g., SIP, XMPP).

Historically, DNS zones were managed with BIND-style zone files and transferred between servers via AXFR or IXFR protocols. Today, most DNS management happens through web-based control panels like cPanel, Plesk, Cloudflare, or Amazon Route 53. These interfaces feature validation tools and syntax checkers to reduce errors.

You can also diagnose DNS record issues using external testing tools such as DNSViz or MXToolbox, making sure your settings work correctly. Automation tools like Terraform and Ansible help deploy and manage DNS records at scale, reducing manual errors.

Common human errors include

• typos;
• TTL misconfigurations;
• improper use of CNAME records.

To prevent these, use tools with record locking, maintain audit trails, and set up change notification alerts. These practices help maintain a reliable and secure DNS setup.

How to Set Up DNS on a Router

Administrators of huge networks with a large number of switching users practice setting up DNS on the router. This solves the problem with the need to configure DNS on each device separately and significantly saves time. What the DNS setting looks like on popular routers, we will tell you in more detail later.

Router TP-LINK Archer A6

To start setting up DNS on this router, you need to find out the IP address of high-quality DNS servers and then follow these steps.

1. Open any web browser and write 192.168.0.1 or 192.168.1.1 in the address bar and click execute to go to the router settings.
2. To get access to the settings, you need to go through authorization by login and password. By default, they are, in most cases, 'admin' and 'admin'.
3. In the settings window you need to click on the "Advanced" tab and select "Network", and then the sub-item "Internet".

   

4. On the right side of the window, you need to open additional settings. This can be done by clicking on the "Advanced" button.

   

5. Scroll down to the DNS address section and set the switch button to “Use the following DNS Address”, then write in the corresponding fields the primary and secondary DNS servers (Primary DNS, Secondary DNS). To apply the changes, click on the “Save” button.

   

Router Tenda AC7

If the DNS servers provided by your provider do not suit you, then you can change them to better ones using the following method.

1. Connect to the router settings using any convenient web browser. In the address bar, write the request 192.168.1.1 or 192.168.0.1
2. On the left in the vertical menu of the router, select the "Internet settings" item.

   

3. Fill in the appropriate fields with your primary and secondary DNS servers, and then click on the "Save / Connect" button.

Asus RT-AC1300G Plus V3

This router has a built-in DNS service that will independently select the best DNS servers. You can activate it or make changes to the settings by performing the following operations.

1. Launch a web browser, and in the address line, write the request 192.168.0.1 or 192.168.1.1 so you can go to the router settings. For authentication, the default username is 'admin' and the password is 'admin'.
2. In the menu settings, click on "Advanced settings", then select "WAN" and open the "DDNS" tab.

   

3. Activate the use of the DNS client by moving the switch to the "Yes" position.

   

4. Select the appropriate DNS server from the drop-down list.

   

5. In the hostname field, you can rename the DNS as desired. Then click on the "Apply" button for the changes to take effect.

   

Security Threats to DNS Servers and Protective Measures

DNS servers face many security threats that can disrupt service or redirect users to malicious sites.

Here are the main DNS attack types you need to know:

• Amplification Attack: Exploits open recursive resolvers to amplify traffic and flood targets with DDoS attacks through reflection.
• Spoofing (Cache Poisoning): Injects false DNS data into caches, redirecting users to harmful IP addresses.
• Flooding Attack: Overwhelms servers with excessive queries, causing disruptions.
• Hijacking: Alters DNS settings at the ISP or device level to redirect traffic for phishing or censorship.

DNS primarily uses UDP, which is connectionless and easier to spoof compared to TCP used in zone transfers. This makes securing DNS servers essential.

Protective Measures for DNS

To protect your DNS server:

• Harden your DNS software by disabling open recursion if not needed and apply rate limiting or Response Rate Limiting (RRL).
• Keep DNS server software updated (BIND, Unbound, PowerDNS, Microsoft DNS) to patch known vulnerabilities.
• Implement DNSSEC to authenticate DNS responses with digital signatures, preventing tampering.
• Use DNS over HTTPS (DoH) or DNS over TLS (DoT) to encrypt DNS queries, improving privacy and blocking interception.
• Deploy firewall rules, intrusion detection/prevention systems like Snort or Suricata, and DNS firewall solutions such as Cisco Umbrella or Infoblox.

For enhanced DNS security infrastructure, Proxy-Seller offers premium private SOCKS5 and HTTPS proxies. These proxies anonymize DNS query origins and control access to your DNS servers, significantly reducing risks like amplification and hijacking attacks. Proxy-Seller’s extensive subnet and network diversity cover over 220 countries, ensuring resilient and reliable proxy routing.

Their proxies integrate smoothly with various security protocols and automation APIs, making deployment with DNSSEC validation tools and security systems efficient. Plus, you get round-the-clock expert support and scalable proxy packages suited for businesses focused on strong DNS defense and automated attack mitigation.

Using Proxy-Seller alongside proper DNS hardening and encryption offers you a practical, effective path to robust DNS server security and reliable internet access protection.

Conclusion

The procedure for changing DNS servers directly depends on the firmware of your router, but the algorithm of actions is the same for everyone. You can register DNS manually or select from the list using the appropriate service if this is supported by the router's firmware. Setting up DNS on the router will allow all devices on your network to connect to the desired sites faster and save time on making changes on a large number of devices.