Creating a custom domain filtering category using the Block List


The Block List is a feature of Cyber Shield Domain Filtering. The Block List enables you to block a defined list of domains, which results in a custom domain filtering category.

You can add domains to the Block List either individually or in batch using a text (.txt) file. Just as you can disable (turn OFF) the blocking provided by a preset domain filtering category, you can disable the Block List.

Note: If you are using both Allow List and Block List, refer to Interaction Between Blocked And Allowed Domain Names.


  1. From the Cyber Shield page, click the pencil icon to access the Domain Filtering blocking settings.
  2. Click the Block List tab.
  3. Add blocked domains to the Block List.
    • To add individual domains, click Add.
      • Matching entries appear as you type.
      • A warning appears if you specify a domain that exists in the Allow List.
    • To batch add domains, upload a text file with multiple domains.
      • The text file must be formatted to contain each domain in its own row.
      • Domain names can’t contain asterisks.
      • When domain validation fails on an uploaded text file, an error icon displays with the domain, along with a description of the validation failure. Failed validation domains aren’t added to the Block List and must be fixed manually.
      • Any existing entries are overwritten by the entries in the uploaded file.
  4. To download the domain names in the Block List as a text file, click the Download List hyperlink at the bottom right.