title: IIS 10 - Windows Authentication - AuthenticationType "unavailable"
body: <p>I am a web app that I'm trying to get working with Windows Auth.  However, no matter what I do, I can't get past a 401.</p>
  
  <p><strong>web.config</strong></p>
  
  <pre><code>&lt;configuration&gt;
    &lt;system.webServer&gt;
      &lt;security&gt;
        &lt;authentication&gt;
          &lt;anonymousAuthentication enabled="false" /&gt;
          &lt;basicAuthentication enabled="false" /&gt;
          &lt;windowsAuthentication enabled="true"&gt;
            &lt;providers&gt;
              &lt;clear /&gt;
              &lt;add value="NTLM" /&gt;
            &lt;/providers&gt;
          &lt;/windowsAuthentication&gt;
        &lt;/authentication&gt;
        &lt;authorization&gt;
          &lt;clear /&gt;
          &lt;add accessType="Deny" users="?" /&gt;
          &lt;add accessType="Allow" users="CABLE\mmulhe200" /&gt;
        &lt;/authorization&gt;
      &lt;/security&gt;
      &lt;tracing&gt;
        &lt;traceFailedRequests&gt;
          &lt;add path="*"&gt;
            &lt;traceAreas&gt;
              &lt;add provider="WWW Server" areas="Authentication,Security,StaticFile,CGI,Compression,Cache,RequestNotifications,Module,FastCGI,WebSocket" verbosity="Verbose" /&gt;
            &lt;/traceAreas&gt;
            &lt;failureDefinitions timeTaken="00:00:00" statusCodes="401.1" /&gt;
          &lt;/add&gt;
        &lt;/traceFailedRequests&gt;
      &lt;/tracing&gt;
    &lt;/system.webServer&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p><strong>IIS Failed Request Trace Output (Partial)</strong></p>
  
  <pre><code>&lt;failedRequest url="http://dev.windowsauthtest.com:80/"
                 siteId="3"
                 appPoolId="windowsAuthTest"
                 processId="33204"
                 verb="GET"
                 authenticationType="NOT_AVAILABLE"               activityId="{80000727-0003-F400-B63F-84710C7967BB}"
                 failureReason="STATUS_CODE"
                 statusCode="401.1"
                 triggerStatusCode="401.1"
                 timeTaken="0"
                 xmlns:freb="http://schemas.microsoft.com/win/2006/06/iis/freb"
                 &gt;
  </code></pre>
  
  <p>The part that concerns me is</p>
  
  <pre><code>authenticationType="NOT_AVAILABLE"
  </code></pre>
  
  <p>I get prompted to enter my credentials and I enter my NT username/password and it just keeps re-prompting.</p>
  
  <p>Any ideas?</p>