In the Ektron Workarea, when you try to add a DXH inbound connection, you see an unable to connect to adapter error. Reviewing the CMS error report gives you this:

Communication error: EKConnector.TestConnection failed: EktronProxy could not login to Ektron: The HTTP request was forbidden with client authentication scheme 'Anonymous'

Please note: This error and solution applies to Version 9 and above of the CMS on a Windows 2012 server.

To correct this problem, head over to the Ektron Web Server and give access to its external IP address.

Here are the steps to accomplish that:

1. On the Ektron Web Server, open IIS
2. Under "Connections" in the left panel, locate the Ektron Web Site
3. Click "IP Address and Domain Restrictions". The Add Allow Restriction Rule dialog should appear
4. Add the external IP address of the Ektron Web server.