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How to Troubleshoot a DNS Server

Mark Lukehart

man troubleshooting a dns server

There are few things more frustrating than trying to access an important website, only to have it display an error message. With so many of us working online these days, this could put a serious dent in your productivity for the day.

A DNS server error is one of the most common errors you’ll encounter while using the internet. This means that the server that connects to the Domain Name System isn’t able to establish a connection.

Several things can cause a DNS server error. They usually happen as a result of issues on the user’s side, rather than the website’s side, although both situations are possible. 

Let’s take a look at why DNS errors happen and how to troubleshoot them when they arise.

Key Takeaways

  • DNS server errors happen when your browser can’t connect to the DNS server and therefore can’t find the IP address for the website you want to visit.
  • Many DNS issues happen as a result of issues with your internet connection, so start by troubleshooting issues with your router.
  • Connecting to a public DNS server or clearing the DNS cache can also be effective solutions.
  • If you’re struggling with DNS issues at work, a professional IT provider can help you solve them.

What is a DNS Server Error?

Think of the DNS as the phonebook of the internet. When you type a domain URL into your browser, the DNS looks up that domain name’s corresponding IP address.

Domain names, such as or, are made up of letters, while IP addresses are made up of numbers. Your computer needs the right numeric IP address to load a website, which is where the DNS comes in.

DNS issues occur when your browser can’t connect to the servers that power the DNS system. When this happens, you’ll receive an error message saying “DNS server not responding” instead of connecting to your desired website.

Common causes of DNS server errors include:

  • Internet connection issues
  • Outdated browser or operating system
  • DNS setting issues
  • Issues with the website’s DNS records

How to Troubleshoot a DNS Server Error

If you encounter a DNS problem, use the following steps to troubleshoot it.

1.Check your internet connection. Many DNS errors stem from an issue with your internet service provider, or ISP. Check to make sure that you are connected to the correct Wi-Fi network.
2.Restart your router. If you are connected to the correct Wi-Fi network but still don’t have any internet access, try turning your router off and back on again. Restarting the router can fix many connection issues.
3.Run network diagnostics. If you’re still encountering network connectivity issues after restarting your router, try running network diagnostics to identify and fix the issue.
  • To run network diagnostics on Windows 10, go to your control panel and find the network settings. Then select troubleshoot problems > additional troubleshooters > internet connections.
  • To run network diagnostics on a Mac, hold the Option key and select the Wi-Fi icon from the top menu bar. Select Open Wireless Diagnostics and follow the instructions.
4.Try a different web browser or device. It’s possible that your DNS issue could be related to issues with your browser. If you’re using Chrome, try switching to Firefox or Safari, or vice versa. You can also try logging onto the website with a different device to rule out device-specific issues. For example, if you’re having issues with a web page on your computer, try loading it on your smartphone.
5.Flush your DNS cache. When you visit a website, your browser stores its DNS responses in the cache. This makes it easier to load the site if you visit it again. When you flush DNS caches, it removes the corrupted or outdated data that could be causing the problem. To flush the DNS cache, use the following steps:
  • On Windows, open Command Prompt and type ipconfig /flushdns.
  • On a Mac, open Terminal and type sudo killall -HUP mDNSResponder.
6.Check your firewall and antivirus software. Sometimes these security programs can accidentally block access to DNS records. Try temporarily disabling or uninstalling them to see if this resolves the issue.
7.Contact your ISP. If you’re consistently getting DNS server errors when you try to access the internet, get in touch with your ISP for more support.

How an IT Provider Can Help

If you’re following these troubleshooting steps at work and are still not finding a solution, an IT provider can help. Your IT provider will help identify the source of the DNS error so you can access the sites you need.

IT support professionals will monitor your office’s internet connection to make sure it is working properly. If issues arise, they will take steps to fix them right away, so that internet issues don’t disrupt your team’s workflow.

They will also make sure that DNS settings are configured properly on all network devices. When installing new cybersecurity measures, your IT team will make sure that they don’t negatively affect your DNS server connections or DNS cache.

Finally, your IT provider can help if your website’s users are reporting consistent DNS server errors. This could indicate that your site’s DNS records are incorrect, or that there are issues with your hosting provider.