What is a DNS Resolver?

Written by Daily Fix - Published 09-Jun-2023, last updated 21-Jun-2024

A Domain Name System (DNS) Resolver is a server that translates domain names into IP addresses. When you type a domain name into your web browser, such as www.google.com, your browser sends a DNS query to a resolver via your Internet Service Provider from your local network. The resolver then looks up the IP address for that domain name and returns it to your browser. Your browser then uses the IP address to connect to the website.

DNS resolvers are an essential part of the internet. They allow us to easily access websites by their domain names, rather than having to remember their IP addresses.

How does a DNS Resolver work?

When your browser sends a DNS query to a resolver, the resolver first checks its cache to see if it has already looked up the IP address for that domain name. If it has, it returns the IP (internet protocol) address to your browser. If it hasn't, the resolver will query a DNS root server.

DNS root servers are the top-level servers in the DNS hierarchy. They store the mapping of domain names to IP addresses for all of the top-level domains, such as .com, .net, and .org.

When a resolver queries a DNS root server, the root server returns the address of a TLD server. The TLD server then returns the address of a DNS server for the specific domain name that you are querying.

The DNS server for the specific domain name then returns the IP address for that domain name. The resolver then returns the IP address to your browser.

Types of DNS Resolvers

There are two main types of DNS resolvers: recursive resolvers and iterative resolvers.

Recursive resolvers

Recursive resolvers are resolvers that query other DNS servers until they find the IP address for a domain name. They are the most common type of DNS resolver.

Iterative resolvers

Iterative resolvers query other DNS servers, but they do not query all of the servers in the DNS hierarchy. They stop querying servers once they find a DNS server that can answer their query.

How to choose a DNS Resolver

There are many different DNS resolvers available. Some of the most popular include:
Google Public DNS
CloudflareDNS
OpenDNS
Quad9

When choosing a DNS resolver, you should consider the following factors:
Performance: How fast is the resolver?
Security: How secure is the resolver?
Privacy: How much of your data does the resolver collect?
Features: What features does the resolver offer?

Benefits of using a DNS Resolver

There are several benefits to using a DNS resolver:
Speed: DNS resolvers can improve the speed of your internet connection by caching DNS queries. This means that the resolver will already have the IP address for a domain name when you next visit the website.
Security: DNS resolvers can help to protect your privacy by preventing your ISP from tracking your browsing activity. Combine using a privacy focussed DNS resolver with a VPN to help protect your internet traffic and the websites you visit from thrid patry prying eyes.
Features: Some DNS resolvers offer additional features, such as parental controls and ad blocking.

Conclusion

DNS resolvers are an essential part of the internet. They allow us to easily access websites by their domain names, rather than having to remember their IP addresses. There are many different DNS resolvers available, so you should choose one that meets your needs.

In addition to the benefits listed above, using a DNS resolver can also help to improve the security of your internet connection. This is because some DNS resolvers offer features such as DNSSEC, which helps to protect your DNS queries from being intercepted by attackers.

If you are looking for a way to improve the speed, security, and privacy of your internet connection, then consider using a DNS resolver. There are many different DNS resolvers available, so you should be able to find one that meets your needs.