Blog / Articles / Guide on How to Prevent DNS Leaks When Using a VPN

Guide on How to Prevent DNS Leaks When Using a VPN

Guide on How to Prevent DNS Leaks When Using a VPN

We all resort to VPNs for that added layer of privacy they offer in our online explorations, entrusting them with the job of keeping our browsing activities under wraps. However, even the seemingly foolproof shield of a VPN can have its own chinks. An improperly configured VPN can betray some crucial metadata about your online trail, such as the domains you visit and the timestamps of your visits, courtesy of a vulnerability known as a DNS leak.

In this article, we aim to unravel the details of DNS leaks - what they are and how they could potentially turn your private browsing sessions' metadata into open books. More importantly, we will venture into the various strategies to mitigate the risks associated with DNS leaks while using a VPN. The goal is to ensure that your online adventures remain private and secure, just as you intended when you opted for a VPN.

What Is a DNS Leak?

A DNS leak occurs during an active VPN connection when DNS requests that should be routed through the VPN’s encrypted tunnel are instead sent directly to the ISP’s DNS servers. This is problematic as it exposes the domains a user visits, undermining the primary purpose of a VPN which is to ensure online privacy and security.

This leakage happens due to VPN or network misconfigurations or software bugs. When you connect to a VPN, all your internet traffic, including DNS requests, should be routed through the VPN's secure tunnel. However, if there's a misconfiguration in your network settings or a software bug in your VPN application, your device might continue to use your ISP’s DNS servers, leading to a DNS leak.

While a DNS leak reveals the domains you are visiting to your ISP, it's important to note that the actual content of your communications remains encrypted and secure within the VPN tunnel. In other words, the ISP can see the domains you are visiting (akin to knowing who you are calling), but cannot decrypt the contents of your conversation or the data being exchanged.

Why Is a DNS Leak a Threat to Privacy?

The concern of DNS leaks stems from their ability to expose a user's online activities to their ISP or other third parties, despite the use of a VPN. This undermines the privacy and security that VPNs are meant to provide. Threats imposed by DNS leaks include:

  • Identity Exposure through Profiling: By profiling and comparing DNS leak data with other profiles, malicious actors could potentially deduce the user's identity, posing personal and professional risks, especially in scenarios where anonymity is crucial.
  • Exposure of Browsing History: DNS leaks reveal the websites and online platforms a user visits to their ISP and potentially other third parties. This exposure can be exploited to build a profile of a user's interests and behaviors.

  • Geographical Location Disclosure: By analyzing the DNS requests, one can infer the geographical location of the user, which can be problematic especially in regions with restrictive internet regulations or political sensitivities.

  • Targeted Phishing Attacks: When malicious actors have access to a user's browsing history through DNS leaks, they can craft personalized phishing messages that appear to come from trusted sources the user frequents, significantly increasing the likelihood of a successful scam.

  • Man-in-the-Middle Attacks: Knowledge of the websites a user frequents allows attackers to set up malicious intermediaries, intercepting and possibly altering the communication between the user and those websites to steal sensitive data like login credentials.

  • Profiling for Targeted Advertising: Advertisers and trackers can use the data from DNS leaks to build a detailed profile of a user’s interests and online behaviors, which can then be used to serve intrusive targeted advertisements, infringing on the user's privacy and potentially creating a nuisance during their online browsing experience.

The ramifications of DNS leaks highlight the importance of ensuring a secure and leak-free VPN connection to maintain Internet privacy and safety.

Step-by-Step Guide to Preventing DNS Leaks

Ensuring a secure browsing experience free from DNS leaks requires a meticulous approach. Here’s a detailed, step-by-step guide to achieving this:

1. Choose a VPN with DNS Leak Protection

  • Selection of a VPN provider: Look for VPN providers that explicitly mention DNS leak protection as part of their features. A well-regarded VPN with DNS leak protection ensures that your DNS requests are tunneled securely through the VPN and not exposed to your ISP.

  • Research and Reviews: Delve into reviews, ratings, and discussions on tech forums to find reputable VPN providers. Look for feedback specifically around the effectiveness of the DNS leak protection feature.

2. Implement DNS Leak Protection Using Firewall (if necessary)

  • Understanding the Need: If your chosen VPN lacks built-in DNS leak protection, a firewall can be configured to ensure DNS requests are securely tunneled through the VPN.

  • Software Firewall Configuration: On your computer, configure the firewall settings to restrict DNS traffic to the VPN tunnel only. This may require advanced configuration, and there are many guides available online to assist with this process.

  • Hardware Firewall Configuration: If you have a hardware firewall (like an internet router with firewall capabilities), log into its configuration settings and set up rules to allow DNS requests only over the VPN tunnel. This may require some technical knowledge or assistance from your network administrator.

3. Disable IPv6

Consider disabling IPv6 to minimize risks of DNS leaks in your system. IPv6, which stands for Internet Protocol version 6, is the modern successor to the older IPv4. It's designed to provide more IP addresses and support the growing number of internet-connected devices. However, it's not without its potential issues. On Windows 10 and Windows 11 systems, IPv6 comes enabled by default. One of the concerns with it is that under certain conditions, it can lead to DNS leaks.

Press the Windows Key + X combination to bring up a quick access menu, and from there, select "Control Panel." Alternatively, you can type "Control Panel" into the Windows search bar and select it from the results. Once inside the Control Panel:

  1. Navigate to "Network and Internet." This section aggregates options related to network connections, Wi-Fi, and ethernet.
  2. Then, proceed to the "Network and Sharing Center," which offers a central hub for viewing and managing network connections.
  3. On the left side, select "Change Adapter Settings." This takes you to a page showing all your network connections, including Wi-Fi, ethernet, and VPNs.
  4. Right-click on the connection you wish to modify (for example, your active Wi-Fi or Ethernet connection) and choose "Properties" from the context menu.
  5. In the properties window, find and deselect the "Internet Protocol Version 6 (TCP/IPv6)" checkbox to disable it.

After completing these steps, IPv6 should be disabled for your VPN connection. It's always a good idea to restart your computer after making network-related changes to ensure they are fully implemented. If you ever need to re-enable IPv6, simply follow the steps above and check the box next to "Internet Protocol Version 6 (TCP/IPv6)" in the network adapter properties window.

4. Regularly Check for DNS Leaks

  • Online Testing: Utilize online tools such as or to test whether your DNS requests are leaking outside the VPN tunnel. These tools provide a simple way to check if your DNS requests are being routed correctly.

  • Routine Checks: Make it a habit to perform DNS leak tests, especially after making any changes to your network or VPN settings. It’s a proactive measure to ensure that the protective measures in place are functioning as intended.

5. Additional Tips

  • Stay Updated: Keep your VPN software and firewall firmware up to date to benefit from the latest security patches and improvements.

  • Seek Professional Assistance: If you're unsure about configuring your firewall or VPN settings, consider seeking assistance from a professional or the VPN provider’s support team.

Is your VPN Leaking DNS Requests?

Obtaining a VPN is a wise move for online privacy, but it's not a foolproof solution. The risk of DNS leaks highlights the importance of not becoming complacent. It's crucial to ensure that your VPN is effectively safeguarding your privacy by checking for possible leaks and employing additional security measures if necessary. Taking these extra steps will provide a more robust shield for your online activities, making the most out of the privacy features your VPN is designed to offer. Take action today by reviewing your VPN settings and ensure you have DNS leak protection enabled. Remember, a secure browsing experience is not a one-time setup, but a continual process. Stay safe, stay secure.

⏴ Back to Blog

Article Summary

What is a DNS leak?

A DNS leak occurs when DNS requests bypass the secure VPN tunnel and are sent directly to the ISP’s DNS servers, potentially exposing the websites you visit.

How do DNS leaks happen?

DNS leaks can occur due to network misconfigurations, software bugs in the VPN application, or when the VPN fails to properly route DNS requests through its secure tunnel.

Why are DNS leaks dangerous?

DNS leaks are dangerous as they expose your online activities to your ISP or third parties, undermining the privacy and security that a VPN is supposed to provide.

How can I check for DNS leaks?

You can check for DNS leaks by using online tools that analyze your DNS requests to see if they are being routed securely through your VPN.

What does DNS leak protection do?

DNS leak protection ensures that DNS requests are securely routed through your VPN's encrypted tunnel, preventing exposure to your ISP or other third parties.

How do I prevent DNS leaks?

Prevent DNS leaks by choosing a reputable VPN with DNS leak protection, configuring your firewall settings, and regularly checking for DNS leaks using online tools.

What information can be exposed in a DNS leak?

A DNS leak can expose the domains you visit, however, the actual content of your communications remains encrypted and secure within the VPN tunnel.

Do all VPNs protect against DNS leaks?

Not all VPNs protect against DNS leaks. It’s essential to choose a VPN known for robust DNS leak protection and security features.

Can a firewall prevent DNS leaks?

Yes, configuring a firewall to only allow DNS traffic over the VPN tunnel can help prevent DNS leaks if your VPN doesn't have built-in DNS leak protection.

Is my geographical location revealed in a DNS leak?

Yes, a DNS leak can potentially reveal your geographical location based on the DNS servers your requests are sent to.

How often should I check for DNS leaks?

It's prudent to check for DNS leaks regularly, especially after changing your network or VPN settings.

Can DNS leaks be fixed?

Yes, DNS leaks can be fixed by either choosing a VPN with robust DNS leak protection, configuring your firewall, or correcting network misconfigurations.

Are there any tools available for DNS leak testing?

Yes, several online tools are available for DNS leak testing that can analyze your DNS requests to check for leaks.

What to do if I discover a DNS leak?

If you discover a DNS leak, consider switching to a VPN with better DNS leak protection, configuring your firewall, or contacting your VPN provider for support.

How does a DNS leak affect my online anonymity?

A DNS leak compromises your online anonymity by revealing the domains you visit to your ISP or third parties, even though your VPN is active.

How does disabling IPv6 help prevent DNS leaks?

By disabling IPv6, you ensure that your device only uses the more commonly supported IPv4 protocol. Most VPNs are well-optimized for IPv4, ensuring that all DNS queries are routed securely through the VPN tunnel. Disabling IPv6 thus removes the potential risk of DNS leaks that might arise from incomplete or improperly configured IPv6 support.

If I disable IPv6, will it affect my online activities or connectivity?

For most users, disabling IPv6 will have minimal impact on their day-to-day online activities. The vast majority of online services and websites support IPv4. However, as the internet transitions to IPv6 over time, there might be specific services or websites optimized exclusively for IPv6. In such cases, you might face connectivity issues. It's essential to weigh the benefits of enhanced privacy against potential connectivity limitations. If you encounter problems, you can always re-enable IPv6.