You must disable Guest View Permissions for intranet pages or categories which are meant to be viewed only by specific user Groups rather than the public.  

Who can use this feature?

Instructions

1. Navigate to Modules > Content > Pages.
   
   
2. Select the Permissions tab.
   
3. Uncheck guest permissions.
   
   
   • Note: This allows you the ability to remove guest viewing permissions from the intranet pages you will create.   
4. Select Save at the top of the page.
   
   • Note: Clicking Save will not uncheck the guest view for any specific pages. It only gives you the ability to turn Guest view on or off on specific pages. 
5. Create intranet pages.