How did you like the article?
6
How did you like the article?
6

DNS server unavailable? Here’s what to do

When your browser isn’t able to establish a connection to the internet, the Windows Troubleshooting function will occasionally respond with the message: ‘DNS server not responding’. There are many factors that can cause this notification to appear. Fortunately, this problem can generally be corrected in just a few simple steps. Find out here about some of the most common causes of problems and their solutions.

DNS: online name resolution

The domain name system (DNS) is a directory service used for transforming alphanumeric domain names into numeric IP addresses. A decentralized process, name resolution generally takes place on DNS servers’ networks distributed throughout the world. Every internet address you enter into your web browser’s search bar is then forwarded by your router to a DNS server. This server then dissolves the domain name into a numeric sequence and returns a corresponding IP address. Should the DNS server fail to produce an answer, then it won’t be possible to access the desired website; the result is the error message ‘DNS server not responding’.

Troubleshooting

The root of such irritating messages can often be traced back to the server outage. In such cases, the DNS server is temporarily unavailable. Most of the time, these problems can be corrected by changing browsers, switching a few of your firewall settings, or restarting your router.

Changing your web browser

In order to rule out that the connection problem isn’t being caused by your web browser, carry out a test by attempting to logon on to the desired web page with alternative applications. Web browsers like Mozilla Firefox, Google Chrome, Microsoft Internet Explorer, and Apple Safari make up some of the most conventional options. If you’re able to solve the problem simply by switching browsers, then check your preferred application’s settings and make sure you’re using the latest version of it. Certain circumstances may require uninstalling the program and reinstalling it again.

Deactivate firewall

In case you aren’t able to achieve your desired results simply by changing browsers, then the next step is to rule out Windows Firewall as the possible culprit. Pull up the control panel and temporarily deactivate the firewall. If you’re now able to access the desired website, then it looks like you’ve identified the Firewall as the source of the problem. Next, check its configuration. Should the error persist even after deactivating the firewall, then the DNS server may yet prove to be the cause of the problem.

Restarting the router

Connection problems can often be solved by restarting the server. Most devices include a power button specifically for this purpose. Should this fail to yield any results, then it looks like a hard reboot may be in store; this is done simply by pulling out the power plug. Wait around 30 seconds until all of the electrical components have completely powered down before starting up the device again. Should you receive the error message ‘DNS server not responding’ after having completed the first two steps, then the only choice remaining is to choose an alternative DNS server.

Selecting another DNS server

If you have ruled out common causes of error such as the router software crashes or conflicts with Windows Firewall, then changing your DNS server could be the solution.

Typically, the DNS server address of the internet provider is automatically used, but this server can sometimes be slow or easily overloaded. A few clicks is all it takes to replace your internet provider’s DNS server with your desired server. Using a public DNS server is also an option; just look on specific DNS server lists. Google operates a fast, free, and very reliable public DNS server.

A step-by-step description of how the DNS server is set up using router settings on Windows 7, Windows 8, and Windows 10, can be found here.

Changing the DNS server via the router

Step 1: Accessing the router

If you want to change the DNS server via your router’s settings, first open your browser and access your router as follows:

  1. Open the command line in Windows (shortcut: Windows key and R), write cmd in the opening line and press enter.
  2. Now enter ipconfig into the open tab and copy the numbers after 'Default gateway' onto the clipboard.
  3. Now copy just the number into your browser’s address field, confirm it, and log in with your relevant access information.

Step 2: Setting up other DNS servers

  1. Choose 'Internet' in the menu and then click on 'Account information'.
  2. Click on the tab entitled 'DNS server'.
  3. Select 'Use other DNSv4 servers'.
  4. If you want to use Google’s DNS server, for example, write 8.8.8.8. in the boxes by 'Preferred DNSv4 server' and next to 'Alternative DNSv4 server' write 8.8.4.4. This specifies an alternative DNS server, which can be used as a backup in case your desired server fails.

Note: If internet protocol version 6 (IPv6) is used instead of version 4 (IPv4), the IP addresses of the DNS server must be changed. Google’s public DNS IPv6 addresses are:

  • 2001:4860:4860::8888
  • 2001:4860:4860::8844

Changing the DNS server on Windows 7/8/10

Step 1: View network connections

To change the DNS server on Windows 7, Windows 8, or Windows 10, you need to access your network connection properties. Click on the Windows button on the task bar and search for ‘Network connections’ then choose ‘View network connections’ in the menu. You can also just enter the command ncpa.cpl.

With Windows 10, you can simply click the right mouse button when hovering over the Windows icon and from there select the menu item, ‘Network connections’.  

Step 2: Select the network adapter

For the second step, you have to select the internet adapter in use. If you’re using a wireless network to access the internet, you need to select the WLAN adapter (wireless network connection). If you’re accessing the internet via cable, then the LAN adapter is the right choice (LAN connection). Once you’ve identified the correct network adapter, right-click and select ‘Properties’ from the menu.

Step 3: Select internet protocol

Now it’s time to choose the internet protocol that should be used. Internet protocol version 4 and internet protocol version 6 are usually the choices given here. Version 4 is used in most cases. Select this one and then click on ‘Properties’.

Step 4: Change DNS server address

The fourth and final step is changing the DNS server address on Windows. The options, ‘Obtain an IP address automatically’ and ‘Obtain DNS server address automatically’ should be selected by default. If this isn’t the case, you should note down which DNS server is being used before you change the server address so that you can undo any changes if there’s a problem in the future and go back to the original settings.

If you want to assign a DNS server address manually, click ‘Use the following DNS server addresses’ and enter the addresses of any alternative servers. If you want to use Google’s DNS server, write 8.8.8.8 in the box next to ‘preferred DNS server’ and then write 8.8.4.4 next to ‘Alternative DNS server’. The second part of information could technically be omitted since this entry only comes into play if the preferred DNS server encounters problems. The top settings including the IP address must remain unchanged, especially if a fixed IP address is entered.

Click 'OK' to confirm the DNS server exchange.

Note: if internet protocol version 6 (IPv6) is used instead of version 4 (IPv4), the IP addresses of the DNS server must be changed. Google’s public DNS IPv6 addresses are:

  • 2001:4860:4860::8888
  • 2001:4860:4860::8844

Changing the DNS Server using PowerShell

You can also use PowerShell to change the DNS server. This method is more suitable for experienced users. With just a single command, you can change the DNS server without having to click through all the Windows menus.

Click on the Windows icon on the task bar, search 'PowerShell', right-click 'Windows PowerShell', and then choose ‘Run as administrator’ from the menu.

Now you can determine the name (alias) of the adapter (i.e. the network cable), which should connect you to the internet. To do this, enter the following command into PowerShell:

Get-NetAdapter|select ifDesc, ifAlias, ifIndex, MediaType | fl

In the example, the name of the adapter is 'Local Area Connection 3'.

If you’re connected to the internet via a LAN cable (ethernet), then you should enter the following command:

Set-DnsClientServerAddress -InterfaceAlias "Local Area Connection 3" -ServerAddresses "8.8.8.8","8.8.4.4"

Instead of 'Local Area Connection 3', you should use the determined interface name.

If you are connected to the internet via WLAN (WiFi), then you have to enter this command:

Set-DnsClientServerAddress -InterfaceAlias WiFi -ServerAddresses "8.8.8.8","8.8.4.4"

The 'WiFi' part needs to be replaced with the name of the adapter being used.

The DNS server addresses, 8.8.8.8 and 8.8.4.4, are the addresses of Google’s public DNS servers. If another public DNS server is used, both addresses need to be changed accordingly in order to comply.

Changing the DNS server using the command prompt

Changing the DNS server by using the command prompt is suited to more experienced users who are familiar with Windows administration. As with PowerShell, no user interface is required when changing the DNS server using this prompt, which makes it easier to maintain the server.

The first step is opening the command prompt as an administrator. If the interface name isn’t given, you can find out what it is using this command:

netsh interface show interface

The primary and secondary servers can then be configured with the following commands: 

netsh interface ip add dns name=" Local Area Connection 3" addr=8.8.8.8 index=1

netsh interface ip add dns name=" Local Area Connection 3" addr=8.8.4.4 index=2

Note: The name in quotation marks must correspond with the exact name of the interface you’re using. Windows doesn’t issue an error message if you accidentally make a mistake.

Checking the new DNS server

You can find out whether changing DNS server has solved the problem by carrying out a simple test. Enter the URL of a well-known site in your browser (e.g. www.google.com). If the site can be accessed it means the DNS server is functioning properly.

If the site can’t be accessed, you can enter the following IP address into your browser: 172.217.16.195. This is one of Google’s IP addresses. If Google doesn’t appear after entering the address, it probably means there’s a general internet problem rather than a problem with the DNS server.

Windows Linux