代理后面的IIS上无法访问Web服务

Question

Spend two days looking through lots of questions but found nothing or may be I am doing something wrong. Basically, I am accessing an AXIS web service from inside a class library, and library is used by web application and windows service. Service reference is added to the class library, both web application and windows service can access the service, and run without any trouble inside visual studio. However when I publish the app, and install windows service, the application throws below error.

ERROR
" There was no endpoint listening at https://bulkmsg.xx.wxyz.com/services/MessagingServices_1 that could accept the message. This is often caused by an incorrect address or SOAP action. See InnerException, if present, for more details. "

WEB.CONFIG (proxy settings)

<defaultProxy useDefaultCredentials="true">
  <proxy usesystemdefault="False" proxyaddress="http://10.51.10.51:8080" bypassonlocal="True" />
</defaultProxy>

I switched the settings from false to true, but I still get the same error. See below the servicemodel section of web.config.

WEB.CONFIG (service settings)

  <system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding name="MessagingServices_1SoapBinding" closeTimeout="00:01:00"
            openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
            allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
            maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
            messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered"
            useDefaultWebProxy="true">
          <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
              maxBytesPerRead="4096" maxNameTableCharCount="16384" />
          <security mode="Transport">
            <transport clientCredentialType="None" proxyCredentialType="None"
                realm="" />
            <message clientCredentialType="UserName" algorithmSuite="Default" />
          </security>
        </binding>
        <binding name="MessagingServices_1SoapBinding1" closeTimeout="00:01:00"
            openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
            allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
            maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
            messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered"
            useDefaultWebProxy="true">
          <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
              maxBytesPerRead="4096" maxNameTableCharCount="16384" />
          <security mode="None">
            <transport clientCredentialType="None" proxyCredentialType="None"
                realm="" />
            <message clientCredentialType="UserName" algorithmSuite="Default" />
          </security>
        </binding>
      </basicHttpBinding>
    </bindings>
    <client>
      <endpoint address="https://bulkmsg.xx.wxyz.com/services/MessagingServices_1"
          binding="basicHttpBinding" bindingConfiguration="MessagingServices_1SoapBinding"
          contract="ZainSmsService.MessagingServices_1" name="MessagingServices_1" />
    </client>
  </system.serviceModel>

Both the web application and windows service are installed on a Win 2008 server, which is connected to internet from behind the proxy.

Since, application is able to access web service inside visual studio but not in IIS, it looks like an permission or some setting issue with IIS, I could be wrong, but that's what I figured out. I am not sure what exactly I should change and where.

UPDATE: more info
I did some digging and managed to find this

Technical Information (for Support personnel)
Error Code: 502 Proxy Error. Forefront TMG denied the specified Uniform Resource Locator (URL). (12202) IP Address: 10.51.10.51
Date: 7/30/2015 6:54:58 AM [GMT]
Server: MUPROXY.MOXXX.GOV.XXX
Source: proxy

Answer 1

It seems that your web service crashes at startup, because of a NullReferenceException (according to the provided eventlog). Therefore the web service could not be reached, so you get this "[...] no endpoint listening [...]" error message.

Can you try to find out, where exactly this NullReferenceException occurs?

Also - if this is possible - you can try to access the webservice directly at the webserver, by just entering the link into a webbrowser. You can get more information if you try this directly at the server.

Answer 2

WORK AROUND

I found a work around, switched from service reference to web reference and used below code to pass on proxy details.

WebProxy _proxy = new WebProxy(_config.GetAppKey("PROXY"), Boolean.Parse(_config.GetAppKey("BYPASSONLOCAL")));
                _proxy.Credentials = new NetworkCredential
                {
                    UserName = _config.GetAppKey("PROXYUSER"),
                    Password = _config.GetAppKey("PROXYPWD")
                };

XXXXSmsService.MessagingServices_1Service _xxxxProxy = new XXXXSmsService.MessagingServices_1Service();
_xxxProxy = _proxy;

Web Referecen plus above code, works like a charm.