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DNS Troubleshooting

If the DNS filter shows 0 requests or filtering isn't working as expected, a caching issue or transparent DNS proxy is usually the cause.

This guide covers troubleshooting for the Bark DNS web filter. If you're troubleshooting the Chrome or Edge extensions instead, refer to this guide.

Background

When the Bark DNS filter is working correctly, you'll see web traffic requests in your web filter reports:

  • At the bottom of the reports, you can see the recently blocked domains and their categories.

  • If you're seeing 0 requests, verify that you've configured the DNS filter correctly, and that there's no caching issue.

  • When you add exceptions for specific domains or categories in your Bark DNS web filter policies, changes should appear on your network-connected devices within a few minutes.

  • Remember, DNS records are often cached on your browser, computer, or network for 5 minutes to 8 hours, which may delay updates. If they're taking a while to apply or web filtering isn't working as expected, please clear your operating system cache and browser cache.
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Clear your operating system cache

Windows 7+

  1. Press ⊞ Win + X

  2. Right-click Command Prompt and select Run as Administrator.

  3. Run the following command and hit enter:
    ​ipconfig /flushdns

Mac OSX 10.9+

  1. Launch the Terminal application

  2. Run the following command and hit enter:
    ​sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Mac OSX 10.8 and earlier

  1. Launch Terminal (under Applications/Utilities)

  2. Run the following command and hit enter:
    ​sudo killall -HUP mDNSResponder

Linux (Ubuntu)

  1. Open a terminal window.

  2. Run the following command and hit enter:
    ​sudo service network-manager restart

Clear your browser cache

Google Chrome (Windows and Mac)

  1. In a new tab, type the following into the address bar and hit enter:
    ​chrome://net-internals/#dns

  2. Click the button labeled clear host cache.

Firefox

  1. Type about:config in Firefox’s address bar and acknowledge the warning that appears

  2. Find an entry called network.dnsCacheExpiration and set it’s value to 0
    ​(If there’s no such entry, create a new integer item with the name above and a value of 0)

  3. Now go back and change the value to 3600

Safari (Windows and Mac)

Resetting the DNS Cache in Windows and Mac automatically flushes the DNS cache on Safari. Nothing to do here!

Advanced Troubleshooting: Transparent DNS Proxy

Before investigating a transparent DNS proxy, make sure you've cleared your cache using the steps above.

A transparent DNS proxy intercepts DNS requests meant for a specific server (like Bark's DNS filter) and redirects them to a different server.

Who is typically affected?

  • Most cable, DSL, and fiber ISPs in North America and Europe do not use transparent DNS proxies.
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  • Satellite ISPs and telecom providers (3G/4G/LTE) commonly use them for performance reasons.
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How do I check for a transparent DNS proxy?

First, make sure your Bark DNS filter policies are configured correctly and your network points to Bark's IP addresses. Then visit DNS Leak Test or WhoIsMyDNS in your browser.

  • If the results show your ISP, your DNS requests are being proxied.
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  • If you see another address (like 8.8.8.8), a firewall or security device may have an outdated rule that needs updating.

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