How to Use Wireshark to Inspect DNS Leaks on Windows?

Vineet Arya
10 Min Read

Ever feel like someone’s watching your every move online—even when you’re using a VPN? It’s not just in your head. That uneasy feeling might be because of something called a DNS leak. And yes, it’s as sneaky as it sounds.

Here’s what’s going on: when you visit a website, your computer asks a DNS server to translate the site name (like google.com) into a number (IP address) it can understand.

Normally, your VPN should keep that info private. But sometimes, those little DNS requests slip outside the VPN tunnel. That’s a DNS leak. And when that happens, your Internet Service Provider (ISP) might see the websites you visit—even though you’re using a VPN.

So yeah, it’s like putting a lock on your door but leaving the window wide open. Not great for privacy, right?

This is where a tool called Wireshark comes in. It might sound technical, but don’t worry—we’ll walk through it step by step.

You’ll learn how to use Wireshark on Windows to check if your DNS requests are leaking out where they shouldn’t. Let’s make sure your online activity stays private, just like it should.

Why DNS Leaks Happen (And What Might Be Causing Yours)

There are a few common reasons why your DNS traffic might be leaking out. Let’s go through them together so you can understand what to look for.

1. Your VPN Might Not Be Set Up Right

Sometimes, a DNS leak happens because your VPN isn’t configured properly. It’s easy to think everything’s working after you click “Connect,” but that’s not always the case.

If your VPN doesn’t handle DNS traffic the right way, your requests might go straight to your ISP instead of staying private.

Always check if your VPN has a feature like “DNS leak protection.” If it does, make sure it’s turned on.

2. Your Computer Is Still Using Your ISP’s DNS

Even with the VPN running, your system might still be using your ISP’s DNS servers. This can happen if your VPN doesn’t offer its own DNS or if the setup didn’t switch it properly. You need to make sure your DNS is going through your VPN, not your local network.

3. Windows Can Override Your Settings

Yeah, Windows can be a bit stubborn. Even if your VPN is working, your system might still fall back to your ISP’s DNS because of how Windows handles network settings. That’s why it’s important to manually check your DNS settings and make sure they’re pointed in the right direction.

4. Conflicting Software Can Cause Issues

You might have other programs on your computer that mess with your network settings. Antivirus software, firewalls, or even another VPN can cause conflicts. When two programs try to manage DNS at the same time, things go sideways. That’s when leaks happen.

If any of this sounds familiar, don’t worry. We’re going to fix it. Let’s walk through the steps to check for DNS leaks using Wireshark and make sure your setup is solid.

Fixes & Solutions for DNS Leaks Using Wireshark

Alright, let’s get hands-on. Wireshark might seem a bit technical, but I promise—if you follow along, it’ll all make sense. You’ll be able to spot DNS leaks like a pro and take control of your privacy again.

#1: Download and Install Wireshark

Before we do anything, we need to get Wireshark on your computer. It’s free and pretty easy to install.

Here’s what to do:

  • Go to the Wireshark website.
  • Download the version that matches your Windows system.
  • Follow the installation steps on screen—it should only take a few minutes.

Once it’s installed, open it up. Don’t worry if it looks complicated at first—we’ll guide you through everything.

#2: Capture Network Traffic

Now, we’re going to start watching what your computer is doing behind the scenes. This is how we catch DNS leaks in action.

  • Open Wireshark.
  • Select your active network adapter (usually labeled Wi-Fi or Ethernet).
  • Click the blue shark fin icon to start capturing traffic.

You’ll see a lot of data flying by—don’t panic. We’ll narrow it down.

#3: Filter DNS Traffic

Let’s make things easier by showing only the DNS-related stuff.

  • In the top filter bar, type dns and hit Enter.

Now, you’re only seeing DNS requests. This is where we’ll spot any leaks.

#4: Analyze the Results

This is where it gets interesting. Take a look at the DNS requests flying through.

  • Check the Destination column. Are the DNS requests going to your VPN’s DNS servers?
  • If you see IP addresses that belong to your ISP, that’s a red flag. It means your DNS traffic is leaking.

Not sure who owns an IP address? You can copy it and use an online tool like IP lookup to check. If it’s not your VPN provider, we’ve got some work to do.

#5: Secure Your VPN and Windows DNS Settings

Now that we know what’s going on, let’s fix it. You want all your DNS traffic going through your VPN—no exceptions.

Here’s what you should do:

  • Open your VPN app.
  • Look for a setting like “DNS leak protection” and make sure it’s turned on.

Now, let’s adjust your Windows DNS settings:

  • Open the Control Panel.
  • Click Network and Sharing Center.
  • Click your active network connection (like “Wi-Fi”).
  • Click Properties.
  • Select Internet Protocol Version 4 (TCP/IPv4) and click Properties again.
  • Choose “Use the following DNS server addresses” and enter your VPN’s DNS addresses.

Click OK to save everything. This ensures your traffic stays where it belongs—inside the VPN tunnel.

#6: Keep Wireshark Updated

Don’t forget this step. Keeping Wireshark updated means you always have the latest tools to detect DNS leaks.

  • Open Wireshark.
  • Click Help > Check for Updates.

Updates only take a minute and keep everything working smoothly.

More Tips to Keep DNS Leaks Away

Now that you’ve tackled the basics, here are a few more things you can do to keep your privacy locked down.

1. Pick a VPN With DNS Leak Protection

Not all VPNs are the same. Some are better at protecting your DNS than others. Choose one that clearly says it includes DNS leak protection. It’s an extra layer of defense—and it’s worth it.

2. Double-Check Your Network Settings Often

Sometimes, updates or new software can mess with your settings. It’s a good idea to go back into your Network and Sharing Center now and then, just to make sure your DNS settings haven’t changed.

3. Run Wireshark Checks Regularly

Think of it like checking your tire pressure. It only takes a few minutes, but it can save you from a big problem later. Open Wireshark, run a quick check, and make sure everything’s still secure.

4. Learn More With Wireshark’s Resources

Wireshark has lots of tutorials and guides on its website. If you want to understand more about how your network works, dive in! A little knowledge goes a long way when it comes to protecting your privacy.

The Takeaway

So, what did we learn? A DNS leak can quietly expose your online activity—even if you’re using a VPN. But with a little help from Wireshark, you can spot and fix those leaks fast.

We walked through installing Wireshark, capturing your network traffic, filtering DNS requests, and checking where they’re going. If anything’s leaking, you now know how to fix it.

Just remember to check your VPN settings, update your DNS manually if needed, and keep an eye on things with regular Wireshark scans.

Privacy isn’t automatic—it takes a little effort. But with these steps, you’re in control.

Got any questions or tips of your own? Drop them in the comments below!

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Vineet is an experienced technology writer and digital analyst who believes in simplifying complex technology topics. He writes extensively on topics such as mobile phones, cybersecurity, and smart home technology for major platforms. His expertise lies in iOS and Android systems as well as Windows and Mac topics. Aside from writing, he also consults startups on strategies to improve their digital conception along with UX implementation. He likes to believe that technology should somehow be about accessibility, empowerment, and easy comprehension.
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