How to check and fix DNS leak error in VPN

The Domain Name Server (DNS) is responsible for resolving domains into the actual IP addresses to connect. When using a secure connection like a VPN tunnel, a DNS leak error occurs when DNS requests are sent over a normal (unencrypted) network instead of a secure tunnel. 

Did you have a DNS leak?

1. How to check for DNS leaks from a browser
2. Check for DNS leaks with Torrent
3. What can you do to prevent DNS leaks?
   1. Use a VPN client
   2. Use custom profiles
   3. VPN kill switch
   4. Firewall

How to check for DNS leaks from a browser

There are several ways to check for DNS leaks. While many VPN services offer their own tools, one of the best ways is to use dnsleaktest.com. The tool is very simple and performs a series of tests that can help reveal leaks that don't appear all the time.

1. When you first go to dnsleaktest.com , the tool will greet you, showing both your IP address and your location. You will also see two options. Choose Extended test .

How to check and fix DNS leak error in VPN Picture 1

Note : The IP address and location should match the VPN server, not your physical location. If you see your physical location there, check the VPN connection again.

2. The site will try several requests to get information about the connection. After each request, it will list the number of DNS servers it can track.

3. When the test is finished, the tool will list all the servers it finds along with their IP addresses and owners. You will only see the servers from your VPN host listed. If you see multiple different IPs, it is usually a sign that the DNS connection is leaking.

How to check and fix DNS leak error in VPN Picture 2 The tool will list all the servers it finds along with their IP addresses and owners

Important Note : VPN providers often rent server space from other hosts, so the names may not match. Instead, pay attention to the IP address. They should match or at least match your external IP.

4. If you've found yourself having a DNS leak, you can always try a new configuration, then go back to dnsleaktest.com and do as much testing as you need to to fix the problem.

Check for DNS leaks with Torrent

Another case where an IP might leak (this is also the one where you want it to leak the least): Torrent. Because Torrents behave differently than regular web traffic, you cannot accurately test your connection to them by the same means. Instead, you will need another tool to check your IP Torrent.

ipMagnet (http://ipmagnet.services.cbcdn.com/) allows you to use a magnet link to determine which IP address the torrent client is displaying to the world.

1. Open a browser and go to ipMagnet. The tool is quite simple, but has everything you need to test your connection.

How to check and fix DNS leak error in VPN Picture 3 Open a browser and go to ipMagnet

2. First, you will notice your public IP address. That should be the VPN's IP. Select the " Magnet link " link on the page and get a unique magnet link to check.

Note : It's best to right-click on it and copy the location without actually visiting.

3. Open the torrent app of your choice and add the magnet link as a new torrent. Your client will start downloading from the link.

4. In the meantime, turn your attention back to the browser. The ipMagnet page will start listing data from the connection. If not, select Update to force it to do so.

How to check and fix DNS leak error in VPN Picture 4 The ipMagnet page will start listing data from the connection

5. The IP address you see listed in the table of ipMagnet should be your VPN address. If not, you are experiencing a leak.

What can you do to prevent DNS leaks?

There are two main steps you can take to prevent a DNS leak. First and foremost, make sure your configuration is correct. This is not always in your hands and depends on how you connect, but do what you can.

Whichever method you choose, you should always take precautions to make sure your VPN connection doesn't leak DNS information. It's imperative to check for and avoid DNS leaks as they can destroy everything you're trying to achieve using a VPN.

Use a VPN client

If you are using a client from your VPN service, make sure you always have the latest version. Keep track of whatever options you have, make sure they match your server, and don't have any noticeable errors. Some clients may even have explicit DNS options.

How to check and fix DNS leak error in VPN Picture 5

Use custom profiles

For those who configure their own client, you can search and make sure your settings match the server. Also, try to download new configuration files from your VPN provider regularly to prevent options from becoming outdated and inaccurate. Mac and Linux users can also write OpenVPN programming and change the system DNS to only use the VPN and revert when you disconnect. Some Linux distributions provide these scripts.

VPN kill switch

There's another option if you're serious about preventing a VPN leak. You can use the VPN kill switch to completely turn off your Internet access when you're not connected to the VPN. Some client software includes a kill switch. Check the client's settings to see if you have any. All settings are usually easy with a checkmark in the corresponding box.

Firewall

The firewall can also act as a VPN kill switch. Firewalls can be set up to block all connections outside of the VPN and local network. A firewall option is not for everyone and is not always the easiest, but can be most reliable.

Samuel Daniel

Update 25 August 2020