Creating simple asp.net core 2.0 web api application (RESTful services only) that uses windows authentication. In my controller I defined a simple test method which just returns the username (json format). When I used a restful client such as fiddler and invoke this method, e.g. http://localhost/webapi/testservice, I get a 401 Unauthorized error. However when I put that url in a Web browser, it invokes successfully and returns the user back.
My question is, why does invoking the service work on the browser but not in a REST client like Fiddler? Is there an additional header I need to add in the client when invoking the service?