Cisco Umbrella allows you to create custom destination lists that contain specific domains or IP addresses that you want to allow or block. You can then apply these destination lists to your policies to override the default behavior of Umbrella. For example, if you want to block specific addresses using Cisco Umbrella, you can create a destination list with those addresses and set the action to block. Then, you can assign this destination list to the policy that you want to modify. This way, any request to those addresses will be blocked by Umbrella, regardless of the content category or application settings12 References := 1: Manage Policies - Umbrella User Guide 2: Understanding Destination lists supported entries and error messages - Cisco Umbrella