What is a DNS server?

Alex Sheehan

Sep 1, 2020 — 4 min read

Learn more about Domain Name Systems, how they work and why you might want to change one (hint: it can help with parental controls).

Ever heard of a term “domain name” when browsing the internet? Essentially, a domain name is a website address. And as of March 2022, there are approximately 350.5 million of them.

Website owners must register their domain name with a hosting company before they can build and launch their site at the desired URL. But computers don’t speak the same language as we do, so those domain names need to be translated into something readable and computer-friendly. 

That’s where the DNS server comes in.

What is a DNS server?

A DNS server matches domain names with IP addresses. Domain names are human-friendly web addresses, like allconnect.com, and IP addresses identify each of those websites with a computer-friendly numerical code, like 123.546.7.8.

What does DNS stand for? You can call it a Domain Name System or Domain Name Server.

How does a DNS server work?

Every device that is connected to the internet has its own IP address. DNS servers use name servers, which essentially act as a directory of IP addresses and domain names. These name servers also dictate how each domain name maps to an IP address. 

A single master name server would be massive and unwieldy, so there are tons of different name servers which store this information. Plus, domain names can each map to several IP addresses. 

Think about it this way: Many people access Allconnect at any given moment, and each of these individuals uses their own device.

So when a human enters a web address, a DNS will match it with the IP address which computers can interpret. This routes your connection to the appropriate destination (the website you’re trying to get to).

Why would you change your DNS?

You know how you might change your IP address with a VPN to gain access to content that’s restricted from your geographical location? Similarly, changing your DNS masks your location. The difference is, a VPN actually reroutes your connection through a different region, while a DNS simply tells the server that you’re in a different location. A VPN also offers more privacy through encryption, which may also slow your connection.

Reasons to change your DNS

  • Access content on the web which is restricted in your physical location (like Netflix)
  • Speed up your internet connection (sometimes third-party DNS servers are faster than the default)
  • Maintain a safe web browsing experience for children
  • Protect your devices and data through third-party DNS servers with added security features (mainly focused on anti-phishing)
  • Your internet connection isn’t working, and you suspect it’s a problem with the DNS

What should you do if your DNS server is down?

There are different indicators that your DNS server might be down, and it’ll require a bit of work on your end if you want to DIY the fix. Some HTTP status codes, such as 502 errors, 503 errors and 504 errors, could all indicate a problem with your DNS.

If you suspect your DNS server is down, there are a few basic ways to confirm or even fix the situation:

  • Connect with a different device – If you’re only experiencing issues on one device while all others can connect without a problem, it’s probably device-specific.
  • Try a new browser or window – All devices having an issue? Open a new web browser or try a different web browsing program/app.
  • Reset your modem and router – This can restart the entire connection which is often all you need.
  • Connect with a hardwire – Plug into your Ethernet cable to see if it’s just the Wi-Fi that’s giving you a hard time.

If you still have a problem after taking the above steps (or you received a “DNS server unavailable” message), it could be your DNS.

Clear the DNS cache

On Mac:

  • Navigate to Applications.
  • Click Utilities.
  • Double-click Terminal.
  • Run the following command: sudo dscacheutil -flushcache
  • If the command succeeds, the system does not return any output.

On Windows:

  • Open the Windows Command prompt.
  • In the open prompt, type ipconfig /flushdns
  • You should receive a message of your success as confirmation when the cache is cleared.

Change your DNS

On Mac:

  • Navigate to System Preferences.
  • Click on Network.
  • Click on Advanced.
  • Go to the DNS tab.
  • Click the + sign at the lower left to add a new DNS server.
  • Type in the numbers of a public DNS server (you can get this from a third-party DNS server).
  • Click OK.
  • Select Apply.

On Windows:

  • Navigate to Network and Internet settings.
  • Click on Change Adapter Settings.
  • Right-click on your active network connection and select Properties.
  • Left-click on Internet Protocol Version 4 (TCP/IPv4) and select Properties. (If you use IPv6, change that as well.)
  • Click Use the following DNS server addresses: and type in a new DNS server address (you can get this from a third-party DNS).

Considering a DNS server? Check out our recommendations for the best free DNS servers and bookmark our Resource Center for guides.

By Alex Sheehan

Alex Sheehan

Written by:

Alex Sheehan

Contributing Writer

Hey! I’m Alexandra Sheehan, a self-employed content strategist and copywriter for B2B companies in the retail, e-commerce and travel industries. I’ve also written for Verizon, Four Season Hotels and Resorts,… Read more

Robin Layton

Edited by:

Robin Layton

Editor, Broadband Content

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