A DNS (Domain Name System) works like a phonebook. On the DNS server, your computer looks up the hostname to find a matching IP address to be linked to the website you’re visiting. Your ISP and other ISPs are responsible for maintaining DNS servers. This enables them to track your internet activities whenever you forward a request to the server. To intentionally hide the record of your activities, you have to use a VPN service. It directs all your DNS queries to an anonymous DNS server, but not directly from your browser. It helps to keep your ISP from trailing your connections. Your browser sometimes overlooks your VPN set-up and forwards your DNS queries directly to your ISP, which is known as a DNS leak.
Causes of a DNS Leak
An imperfect configuration of network settings is one of the major causes of DNS leaks typically associated with using a VPN. This issue is usually common with the Windows OS as it’s more prone to DNS leaks. This happens because the Windows OS adopts a DNS server usually hosted by the LAN (Local Area Network) getaway, instead of the DNS server hosted by the VPN service. The DNS server hosted by the LAN getaway will ultimately send all your queries to your ISP, thereby disclosing your data. If you frequently switch between networks from a hotspot, to a router, you are most susceptible to this cause of DNS leak. Lack of accurate settings in place leaves you open to data leaks.
The absence of IPV6 address support in VPN: Not every VPN service has caught on with the gradual replacement of IPV4 with IPV6. In such cases, IPV6 address will be ignored by the VPN service and eventually taken care of by your ISP. This move naturally avoids the encryption of the VPN tunnel and leaves your private data open to your ISP’s prying eyes.
Built-in OS features like Toredo can cause DNS leaks by interfering with your DNS queries and traffic. Toredo is an innovative technology by Microsoft, built into Windows OS to help boost compatibility between IPV4 and IPV6.
DNS leaks can be caused by devices being conned into directing DNS traffic outside the VPN tunnel. This is typically an indicator that a cybercriminal has taken over your router or network.
How to Detect DNS Leaks?
Some of the DNS leak tests are:
- In-browser tools developed by VPN services to promptly check for DNS leaks.
- Websites which automatically check if your location and IP address you are using are the actual ones or not.
- Using Command Prompt (CMD) and a chosen test server to check if your personal or local IP matches the result of the test or not.
How to Put a Stop to DNS Leaks?
Proper Set-up of VPN Services on Your Computer
This set-up is done in such a way that the computer prefers the DNS server favored by your VPN. This will enable DNS queries to go through the VPN instead of coming right from the local network. Depending on your VPN provider and the protocol you are using, you could accurately set up your computer to;
- Connect manually to your selected DNS server each time you make a request or,
- Automatically connect to the right DNS server irrespective of the local network you are connected to.
You could inquire of your VPN service provider on the particular instructions on how to effectively use their DNS servers or a viable alternative if they don’t have one.
Change Your DNS servers
In cases where VPN service providers don’t have their own DNS servers, connecting to an independent server is the best alternative. It ideally allows DNS queries to go through your VPN rather than going through the DNS server of your ISP. This might even result in faster internet connections.
Other effective ways of putting a stop to DNS leaks include:
- Promptly changing your VPN service if it does not support IPV6 traffic
- Upgrading to a VPN service that combats transparent DNS proxies
- Disabling built-in OS features that might interfere with DNS requests. A classic example is the Toredo technology in the Windows OS
- Disabling IPv6
How Are DNS Leaks Prevented?
- Using a Guaranteed, Independent Server
This preventive method requires you to change the TCP/IP settings on your computer, router, or network adapter. The settings are modified to accurately indicate the specific trusted DNS servers by their IP address. Some VPN service providers have their own DNS servers, so using their service automatically links you to their servers. You can use an open, third-party DNS server as a preferred alternative for the VPN service without a DNS server.
- Using a Firewall on Your VPN to Block Non-VPN Traffic
You can configure your firewall or use a third-party firewall to permit traffic in and out via your VPN. The firewalls can be tested from time to time to ensure it is working properly. Configuring your firewall ensures that your browsing activities remain protected when your VPN service is down or disconnected.
- Performing Routine DNS Leak Test
It is important to routinely check for DNS leaks irrespective of the preventive methods employed. This will help to ensure that the methods to prevent DNS leaks are still functioning.
- Adopting the use of “monitoring” Software
VPN monitoring software ideally allows you to monitor the movement of your VPN traffic. It shows that when your traffic is going to the wrong servers. Some VPN services offer added automatic tools that aid in fixing DNS leaks when spotted.
- Upgrading or Completely Changing Your VPN Service
You might have to change your VPN services if they don’t offer the necessary tools that effectively help manage DNS leaks. An optimal VPN service should have:
- Complete compatibility with the IPV6 protocol
- Ability to completely disable IPv6
- In-built protection for DNS leaks
- Proper functions incorporated into their software to prevent transparent DNS proxies
With the options available for preventing DNS leaks, the best way remains the use of a VPN service that comes with built-in DNS leak protection.
Our Unlimited VPN gives you access to a huge amount of VPN servers and IP-s across the world with unlimited bandwidth and server switching!