What Is A DNS Leak And How To Prevent It?

Hacking attempts have grown smarter, given the increased use of remote access to Internet connections. The presence of public Wi-Fi connectivity has also led to severe vulnerabilities in the connections offered by Internet Service Providers (ISPs). Moreover, given the increasing number of cyberattacks and ransomware attacks on personal computers and corporate networks has brought the confidentiality and security of data stored on cyberspace in question.

And now, hackers and cyber attackers don’t have to access your system; all they can do is breach your Internet network and eventually divert you to malicious websites to infect your system and entire browser activity. One such mode of attack is to breach into DNS, also known as DNS leaks.

In this write-up, we discuss more on DNS leaks, its symptoms on the network, and how to check on them.

What is DNS?

DNS stands for Domain Name System, which acts as a database of corresponding IP addresses to websites a user visits via a browser. When you enter a website URL on the browser, the ISPs can’t directly connect you to the site just by the domain address. You need a matching or corresponding IP address to that site’s servers to make the communication between your browser and the website.

Since it’s impossible to remember the complex IP addresses, ISPs use DNS servers to store all the corresponding IP addresses to the websites you want to visit. The DNS server automatically matches the domain name with the IP address and help you access the website.

Read More: How To Find And Clear DNS Cache On Mac Completely

Which DNS Server You Use?

Well, you technically don’t. It’s your Internet service provider who owns one. Your Wi-Fi router acts as a pathway for your DNS requests to reach the DNS server, then transferred to the website.

You can always check what DNS server your device uses to get the IP addresses of websites you are browsing by visiting this website – What’s My DNS Server?

What is a DNS Leak?

DNS Leak

Unfortunately, these DNS servers are prone to cyber-attacks and can expose your private information concerning your browser activity to the attackers. Also, the information is already visible to the ISPs making it less secure than it should be.

Sometimes, hackers peep into the DNS requests your device makes to your ISPs or try to breach the DNS servers’ security to get further information on users’ browser activities, ultimately leading to a significant breach or exposure of your data. This is termed as DNS Leaks.

Read More: How to Fix DNS Server Not Responding – Windows 10

 What are the Reasons for a DNS Leak?

There are several reasons for a DNS Leak to occur. Here are a few:

  • Problem in Network Configuration:

When connecting to the Internet, ensure that you use a single and stable connection. It often happens that sometimes the connection breaks for a few seconds before a new connection is established. This causes the IP address to change. When this change occurs, you might get connected to your ISP’s DNS server, even if you’re using a VPN. Hackers may penetrate the connection since your VPN won’t work due to the sudden change in the IPs and expose your information.

  • IPv6 Leaks

    IPv6 Leaks

Most IP addresses consist of four sets of 3-digit codes such as; this is called an IPv4 address. However, the Internet is slowly transitioning into the IPv6 phase, where the IP addresses consist of eight sets of 4 codes, which may also include letters.

In most cases, if you send an IPv6 request to your DNS server for a website that still has an IPv4 address, the connection security might lapse. Even in the case of a VPN connection, an IPv6 request bypasses the VPN encryption if the VPN does not explicitly support IPv6 connection security.

Read More: Steps on How to Change your IP Address in Windows 10

  • Transparent DNS Proxies:

VPN tunnels your connection through a third-party server before reaching your ISPs DNS servers to mask your IP address. This also refrains ISPs from collecting or monitoring your data or online activities. Sometimes, ISPs use a separate or proxy server to redirect your requests and web traffic to their servers again—this way, ISPs force DNS leaks to collect user information in many cases.

Read More: Windows Could Not Detect Network Proxy Settings Error Automatically? Here’s The Fix

  • Windows “Smart Multi-Homed Name Resolution” Feature

“Smart Multi-Homed Name Resolution” is a feature that was introduced by Windows in version 8.0. The feature allows connection with other non-standard servers then the one owned by respective ISPs, if the ISP servers become unresponsive. With Windows 10, the feature enables accepting response to DNS requests by any fastest server available. Since this allows users’ IPs to be read by different servers, it can cause significant problems associated with DNS leaks.

  • Teredo:


Teredo is a Mircosoft-developed technology that allows users to find IPv6 compatible connections with the websites and have a smooth transition fro IPv4 to IPv6. In this technology, your IPv4 request is tunneled in a way that IPv4 website addresses pick them. However, this process can bypass your VPN tunneling process and expose your IP address, thus causing a DNS leak.

How to Prevent DNS Leaks?

1. Use an Effective VPN Service

You can always prevent several DNS leaks and associated issues if you use the right VPN service. Do keep in mind that it must not be a free VPN service provider as they do not offer decent protection against possible DNS leaks and often results in connection drops.

Systweak VPN

Systweak VPN is one of the most reliable VPN services. Supported by servers from more than fifty regions across the globe and secured by AES 256-bit military-grade encryption, Systweak VPN provides the utmost protection to users’ DNS requests. Moreover, Systweak VPN also allows bypassing of geo-restrictions on streaming platforms.

Here are some specifications of Systweak VPN:

No. of Devices per Account: Unlimited

Security: AES 256-bit military-grade encryption and provides support for OpenVPN and IKEv2 protocol.

Supported Streaming Sites: Netflix, Amazon Prime, BBC, Kodi, FuboTV, SlingTV, Disney+, AT&T, Hulu, Hotstar, and more.

Number Of Servers & Regions: 50+ Countries

Consumer Support: 24*7

OS Supported: Windows 10/8.1/8 and 7 (both 32-bit and 64-bit)

Price Plan: Monthly: US$ 9.95 || Yearly: US$71.40

Money-Back Guarantee in 30 Days

Free Trial: Available

2.  Use Anonymous Browsers

The Tor browser is regarded as one of the most secure browsers for surfing. It uses onion routing to mask or hide your data and IP address. It jumps over three different locations allowing for extensive geo-spoofing and hiding most information associated with a particular connection.

How to Check DNS Leaks?

You can always check DNS leaks via visiting these two websites:

To find if the connection is leak-free, see that:

– The resulting IP address is the same as the VPN’s one and not the real one.

– See if the test results name your ISP, it signals a DNS leak.

Do not use a DNS Test tool that is offered within the VPN application as it never shows the right result and will not point out any defect in its VPN-secured connection.

DNS Leaks are widespread, especially since hackers are developing new techniques to find possible breaches in networks. However, using the right VPN and aggressive monitoring of your browser activity can help you reduce them.


  • comment_avtar
    Gajendra singh
    Does Systweak VPN keeps our data safe

    4 years ago

Leave a Reply

Your email address will not be published. Required fields are marked *

Subscribe Now & Never Miss The Latest Tech Updates!

Enter your e-mail address and click the Subscribe button to receive great content and coupon codes for amazing discounts.

Don't Miss Out. Complete the subscription Now.