By default Web Control doesn't block or report on IP addresses on the local private network. You can block all internal sites in the Options settings.
To allow specific sites in the local private network, add them to the Block and Allow List.
Task
Select Menu → Policy → Policy Catalog, then select Endpoint Security Web Control from the Products list in the left pane.
From the Category list in the right pane, select Options.
Click the name of an editable policy.
Deselect Allow all local IP addresses in the local network.
Click Save.