Richard,
Based on the Exception message, check the Service Account that is used to bind to your internal AD. Groups & Settings -> All Settings -> System -> Enterprise Integration -> Directory Services. Under the Server tab, scroll all the way to the bottom and 'Test Connection'. If you don't get a response below that button that reads ' Connection successful with the given server name, bind user name, and password.' work with your AD team to determine if they see any errors. Account locked? If not, and no invalid passwords received, then look into the path between your console and the DNS server resolving the name. I see that you have Cloud Connector. Check the Cloud Connector logs.