Test a policy
It is common for a misconfigured Gateway policy to accidentally block traffic to benign sites. To ensure a smooth deployment, we recommend testing a simple policy before deploying DNS filtering to your organization.
- Go to Gateway > Firewall policies.
 - Turn off all existing DNS policies.
 - Turn on any existing security policies or create a policy to block all security categories: 
Selector Operator Value Action Security Categories in All security risks Block  - Ensure that your browser is not configured to use an alternate DNS resolver. For example, Chrome has a Use secure DNS setting that will cause the browser to send requests to 1.1.1.1 and bypass your DNS policies.
 - In the browser, go to 
malware.testcategory.com. Your browser will display:- The Gateway block page, if your device is connected via the WARP client in Gateway with WARP mode.
 - A generic error page, if your device is connected via another method, such as Gateway with DoH mode.
 
 
- In Logs > Gateway > DNS, verify that you see the blocked domain.
 - Slowly turn on or add other policies to your configuration.
 - When testing against frequently-visited sites, you may need to clear the DNS cache in your browser or OS. Otherwise, the DNS lookup will return the locally-cached IP address and bypass your DNS policies.
 
You have now validated DNS filtering on a test device.