Common Questions & Troubleshooting

Before You Begin: Provide Context

When reaching out for support, it helps to have the following information ready:

1. What steps have you already taken?
2. Are you using a Free or Paid plan?
3. What is the specific problem you are experiencing?
4. Which operating system are you using? (Windows, Mac, Linux, etc.)
5. Did you configure this locally on a device or at the router level?

Cause 1: Router or Device Misconfiguration

Router Issues: DNS configuration must be set in the Wide Area Network (WAN) settings to cover your entire network. Check our router guides for model-specific instructions.

Device Issues: The most common mistake involves configuring the wrong network interface. Also, ensure you are not mixing Free and Paid DNS addresses — they use different IP addresses.

To verify which filter you are using, run:

nslookup -type=txt debug.cleanbrowsing.org

The response will reveal which CleanBrowsing filter version is active.

Cause 2: DNS Hijacking by ISP or Software

Your ISP or antivirus software may be intercepting DNS queries. Test this by running:

nslookup badexample.com 185.228.168.10

The expected result is: server can't find badexample.com: NXDOMAIN

If you receive an IP address instead, something is hijacking your DNS. Common culprits include:

• Antivirus software (Avast, AVG)
• ISP "Protected Browsing" features (e.g., Comcast Xfinity)
• Router-level DNS interception

Cause 3: IPv4 vs. IPv6 Configuration

Many modern devices default to IPv6. If you only configured IPv4 DNS, your device may bypass CleanBrowsing entirely.

CleanBrowsing offers IPv6 alternatives for free filters and supports IPv6 activation on paid plans through the dashboard. Make sure to configure both IPv4 and IPv6 DNS settings.

Cause 4: Network Compatibility Issues

Sometimes problems stem from incompatible routers, unusual network topology, or ISP restrictions that require prior authorization before DNS changes can take effect.

If you suspect a network-level issue, try configuring DNS directly on a single device first to rule out router problems.

Cause 5: Routers That Do Not Allow DNS Changes

Some ISP-provided routers prevent DNS modifications entirely. If your router does not allow you to change DNS settings, check our generic router guide for workaround options, or configure DNS directly on individual devices instead.

Cause 6: Content Slipping Through Filters

If inappropriate content bypasses detection, please report it to support@cleanbrowsing.org so we can improve our filtering systems.

For persistent issues, our support team can arrange a screen-sharing session for hands-on troubleshooting.