You can mark links to a domain as internal by entering the domain in the Link Whisper settings. Open the settings and go to the “Advanced Settings” tab. In the tab near the middle of the page you’ll see a field called “Mark Domains as Internal”. This is where you enter the domains you want to mark as internal.

To enter a domain, first copy it as it appears in your browser’s address bar.

Then paste the copied url into the “Mark Domains as Internal” field and click the “Save Settings” button.