Introduction
This document describes if you can block uncategorized or unclassified domain categories in Umbrella.
Blocking Uncategorized or Unclassified Domain Categories
Blocking uncategorized or unclassified categories for domains is not possible in Umbrella. Blocking this category can result in a poor Internet browsing experience for users. Domains serve multiple protocols beyond HTTP. Because Umbrella categorizes domains at the DNS layer, domains without HTTP content cannot be classified. This includes domains used for protocols such as FTP or SSH.
If an "Uncategorized/Unclassified" category existed in Umbrella, blocking it can block all domains used for non-HTTP protocols.
Solution
As an alternative, you can use the "Newly Seen Domains" Cisco Umbrella security category to achieve functionality similar to blocking uncategorized/unclassified domains. Read more in the Umbrella Knowledge Base about blocking with "Newly Seen Domains."