Enforcing Online Safety with DNS Safe Search on Zyxel Firewalls

Zyxel_Lynn

While DNS Safe Search isn't a new feature for Zyxel firewalls—having already been available in Nebula-managed ZLD models—firmware updates have refined and expanded its usability. This feature is especially beneficial for households, schools, and any environment where stricter content control is needed.

What IS DNS Safe Search?

Most search engines, like Google, YouTube, and Bing, offer a “Safe Search” mode to filter out explicit or inappropriate content. However, this setting is user-controlled, meaning anyone (including children) can manually turn it off in the browser settings.

DNS Safe Search solves this issue by enforcing Safe Search at the network level, regardless of the client’s browser or settings.

How It Works

When DNS Safe Search is enabled on your Zyxel firewall:

• Any DNS request for a search engine (e.g., www.google.com) from a LAN-side device is automatically redirected to a special version of that search engine’s server.
• These alternative servers are maintained by Google, YouTube, and Bing, and always enforce Safe Search—users cannot disable it.

Supported Platforms:

• Google Search
• YouTube Search
• Bing Search

For example, when a user visits Google from their browser, the firewall redirects the request to forcesafesearch.google.com, which locks the Safe Search mode and displays a banner like:

“SafeSearch is locked by your network or device.”

This ensures inappropriate content is filtered out, even if the user tries to manually disable Safe Search in the browser.

How to Enable DNS Safe Search

To activate this feature:

1. Go to Content Filtering in your firewall's web GUI.
2. Enable the DNS Safe Search checkbox.
3. Create a profile if needed and apply it to a security policy that targets LAN-side clients.

Verification

To verify it’s working:

• Connect a device to the network.
• Go to Google or YouTube and perform a search.
• You should see a Safe Search message stating it’s locked by the network.
• Searches for sensitive terms will return filtered results, often with educational or news content rather than explicit sites.

Ideal Use Cases

• Parental Controls at home
• Classroom Filtering in schools
• Public Wi-Fi in libraries or cafes
• Guest Networks in corporate or retail environments

DNS Safe Search is a simple but effective tool to ensure a safer browsing environment for users of all ages. By enforcing filtering at the DNS level, you remove reliance on browser settings or user cooperation—giving network administrators full control over safe content delivery.