How To Fix The “DNS Server Unavailable” Error

A Domain Name System (DNS) server is a place where all the domain names of the sites you have visited are stored. When you search for a domain name in a web browser, your router will forward it to the DNS server. If the domain name of a specific site has been saved, the corresponding IP address is returned. This makes the loading process for these sites extremely fast.

Although this process is excellent, it is not uncommon for DNS servers to fail to establish a connection from time to time. Attempting to troubleshoot the web browser in this situation will usually result in a “DNS server not responding” error.

Many factors can cause this particular error to appear on your screen. The most prominent is the possibility of the server itself experiencing an outage. Fortunately, this problem is usually accompanied by some simple solutions.

How To Fix The “DNS Server Unavailable” Error

Have you ever received an error message that the DNS server is unavailable? To quickly resolve these issues, simple methods such as changing the browser, modifying some firewall settings, or restarting the router can sometimes be used to correct these issues. It is up to you to find out the cause of the problem and make any subsequent corrections.

First use a different browser for the webpage you are trying to open. This means that if you are currently experiencing an error while using the Mozilla Firefox browser, please switch it to Microsoft Edge or Google Chrome. If the problem persists, we can continue to test other devices.

Try to open the web page with a mobile device on the same network to ensure that the problem is not the result of a hardware failure. It is also beneficial to try to connect to the same web page using your data plan to determine if the cause is actually related to the DNS server.

After completing these steps, restart the router. If the error “DNS server is not available” persists, we will have to take some more effective methods.

Flushing Your DNS (Windows)

The most effective method for fixing the issue with the DNS server being unavailable is to flush it using Command Prompt.

Pull up the Run dialog by simultaneously pressing the Windows key and R key.
Type cmd into the field and press Enter.
In the Command Prompt window, type ipconfig /flushdns and press Enter.

Follow up by typing ipconfig /release and press Enter.

Finally, type ipconfig /renew and press Enter.

Close out of the Command Prompt window and reboot your system.

Flushing Your DNS (MacOS)

You can also update DNS on your Mac. How you do this will vary slightly depending on the version of Mac your computer is running. Usually it only involves changes to the syntax used in the process.

Open a Finder window and then head into Applications, followed by Utilities, and ending in the Terminal.
Enter in the following syntax pertaining to the version of MacOS you’re currently using:
- MacOS High Sierra – sudo killall -HUP mDNSResponder; sleep 2; echo macOS DNS Cache Reset | say
- MacOS Sierra – sudo killall -HUP mDNSResponder;say DNS cache has been flushed
- MacOS Mojave – sudo killall -HUP mDNSResponder;sleep 2;
- MacOS X El Capitan/Yosemite – sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder;say cache flushed
Press the Return key, enter your password, and then hit the Return key once more.
Await the audio alert that indicates a successful DNS flush before exiting the Terminal.

Clearing the MacOS X cache requires a few extra steps to clear it completely. You must flush the MDNS and UDNS caches in addition to the steps above.

Before exiting from the Terminal, perform the following commands:

For the MDNS cache, type sudo discoveryutil mdnsflushcache
For the UDNS cache, type sudo discoveryutil udnsflushcaches

Remove Multiple Antiviruses

“You will never have too much protection.” This may be true in the real world, but in the technological world, installing multiple antivirus programs on the same computer can hamper the protection provided.

Check if there are two or more antivirus programs running as this may be the cause of DNS problems. After disabling all other programs, reboot the system and the problem should resolve itself.

Make sure to continue, just run a software program to protect yourself from harmful malware attacks. This not only improves security, but also helps you avoid further DNS server errors.

Changing DNS Servers

If you have tried all the fixes written here and still get the same “DNS server unavailable” error, it may be convenient for you to change the DNS server. There are many public DNS options and Google’s free DNS is one of the most popular options.

The process is very simple and can be done in just a few clicks, depending on the shift location you choose. We will use the Windows operating system in each example.

DNS Changes via Router

Access your router by launching a web browser and entering the default gateway address in the URL field.
- You can find the default gateway by opening a command prompt window, typing ipconfig, and pressing Enter. Copy the number next to the default gateway in the extracted information.

Use the correct credentials to log in to the router.
Found your Internet account information, which can usually be found in a tab with a similar name.
Browse to the DNS server and select the option that best reflects the Internet protocol (IPv4 or IPv6) you are using.
Enter the address of the DNS server you want to use, not the current address.
Google’s DNS server will be 8.8.8.8 in the preferred DNSv4 and 8.8.4.4 in the alternate DNS server. In the case of IPv6, you’ll want to use 2001:4860:4860::8888 and 2001:4860:4860::8844 respectively.
Save the edited information and exit the router interface.

DNS Changes via Windows OS

Access your network connection properties by launching the Run function (Windows key + R) and typing in ncpa.cpl. Press Enter.

Windows 10 users can right-click the Windows icon at the bottom left of the desktop screen and select Network Connection from the menu.
Select the network adapter currently in use. WLAN for WiFi and LAN for direct connection are connected, usually via an Ethernet cable.
- Windows 10 will provide your options on the left panel. Choose one and choose the Change Adapter option from the main window.
Right-click your choice and select Properties.

In the Networking tab, highlight your IP version (v4 or v6) from the menu and click the Properties button.

Click the radial for Use the following DNS server addresses: to enable editing capabilities.

Enter in the DNS server addresses you plan to use.
- If the DNS server you used before was not obtained automatically, please remember to write down the address in case you need to use it again in the future.
Finalize the changes by clicking OK.

Test New DNS Server

After changing the DNS server, open your browser and try starting a well-known website, such as www.google.com. If the site is accessible immediately, the new DNS is working normally. Otherwise, enter one of Google’s IP addresses, 172.217.16.195 directly into your browser and hit Enter.

Wait for the familiar Google logo and search bar to appear. If this also fails, then the problem may be with the internet, not the DNS server itself. If this is the case, contact your Internet Service Provider for further assistance.