Single Instance of HttpClient with UseDefaultCredentials - asp.net

Question

I have been trying to update my API call using the suggestion from here
to only have 1 instance of HttpClient. https://aspnetmonsters.com/2016/08/2016-08-27-httpclientwrong/#
This works fine and I have my do not use up all of the ports, however when I try to create a HttpClientHandler to pass along the default credentials my ports start being used up again. My API is setup to use Windows Auth for security reasons so I need to pass along the app pools credentials for a successful call.
Here are the 2 code blocks
public static class WebApiCallUtility
{
private static HttpClientHandler _handlerNoCred = new HttpClientHandler();
private static HttpClient _clientNoCred = new HttpClient(_handlerNoCred);
private static HttpClientHandler _handlerCred = new HttpClientHandler { UseDefaultCredentials = true };
private static HttpClient _clientCred = new HttpClient(_handlerCred);
//Working ports are not used up
public static HttpResponseMessage SendHttpGetRequestNoCred(string webApiUrl, string logSourceName, string subId)
{
_clientNoCred.DefaultRequestHeaders.Accept.Clear();
_clientNoCred.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage result = _clientNoCred.GetAsync(webApiUrl).Result;
return result;
}
//No working tons of ports open hanging out with TIME_WAIT status
public static HttpResponseMessage SendHttpGetRequestCred(string webApiUrl, string logSourceName, string subId)
{
_clientCred.DefaultRequestHeaders.Accept.Clear();
_clientCred.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage result = _clientCred.GetAsync(webApiUrl).Result;
return result;
}
}
Any help would be appreciated.
Thanks

Answer 1

I was able to revolve this issue buy using a different handler type
private static WebRequestHandler _handlerCred = new WebRequestHandler
{
UseDefaultCredentials = true,
UnsafeAuthenticatedConnectionSharing = true
};
private static HttpClient _clientCred = new HttpClient(_handlerCred);
I found this answer here Static HttpClient still creating TIME_WAIT tcp ports