no response from webservice

[Jan]

For an educational program I use a webservice for acces to a central database
on a remote server. The webservice is is being accessed over https. So far
this worked fine on the computersystems in the about 20 schools that are
participating.
On one school however, a problem occurs since they changed from internet
provider.
The problem seems to be to get the response back from the webservice. This
is the error message:
System.Net.WebException: Underlying connection closed: can't make connettion
with remote server
at System.Net.HttpWebRequest.CheckFinalStatus()
at System.Net.HttpWebRequest.EndGetResponse(IAsyncRes ult asyncResult)
at System.Net.HttpWebRequest.GetResponse()
at System.Net.Connection.TunnelThroughProxy(Uri proxy, HttpWebRequest
originalRequest, Socket& socket).

I don't call the HttpWebRequest methods directly from my code, they are
called from within the webserviceproxyclass that I generated with wsdl.exe.

The problem only occurs when the user doesn't have administrational rights.
When the adminstrator himself logs in on the computer, calling the webservice
works fine, like before.

I have no clue yet where to look for the solution. Any suggestions would be
very welcome.

Additional information about the schools LAN (from where the program is
executed): server had windows 2000, clientcomputer has windows XP.
Internetconnection over asdl, no proxyserver used.

Jan

[Siegfried Glaser]

Maybe a dumb answer but I'm pretty new to this stuff. Have you allready tried
to use the webservice with your browser? The errormessage makes me believing,
you simply aren't allowed to access the webservice's URL.

Sigi

[Jan]

thank you for your reaction. In fact your suggestion was the first thing I
tried. When they use the browser they get to see the normal presentation of
the webservice. So in that way nothing goes wrong.

Jan

"Siegfried Glaser" wrote:

Maybe a dumb answer but I'm pretty new to this stuff. Have you allready tried
to use the webservice with your browser? The errormessage makes me believing,
you simply aren't allowed to access the webservice's URL.

Sigi

[Siegfried Glaser]

Another posting brought me to a new idea. Does your Client use the IE proxy
settings?

The posting I refer to has the subject "proxy support" and was postet by
"Scott" at 01.02.2005 18:04.

[Jan]

In addition to my first post the following question: I try to find
information about the "TunnelThroughProxy" method. According to the error
message this should be a method of the System.Net.Connection class. But in
Microsofts reference I cannot find either a System.Net.Connection class or a
TunnelThroughProxy method. Does anyone have suggestion how to find
information about these?

Jan

[Dilip Krishnan]

Hello Jan,
Those are private/internal classes, thats why. If you really want to dig
in you would need to use reflector [0]
[0] - http://www.aisto.com/roeder/dotnet/

HTH
Regards,
Dilip Krishnan
MCAD, MCSD.net
dkrishnan at geniant dot com
http://www.geniant.com

In addition to my first post the following question: I try to find
information about the "TunnelThroughProxy" method. According to the
error message this should be a method of the System.Net.Connection
class. But in Microsofts reference I cannot find either a
System.Net.Connection class or a TunnelThroughProxy method. Does
anyone have suggestion how to find information about these?

Jan

[EasyStar]

Hi Jan, I am experiencing a similar problem and wonder if you have found a solution?

We get this message when attempting to bypass the configured proxy server by configuring an exception in Internet Explorer or adding an entry to the BypassList:

System.Net.WebException: The underlying connection was closed: Unable to connect to the remote server. ---> System.NullReferenceException: Object reference not set to an instance of an object.
at System.Net.Connection.TunnelThroughProxy(Uri proxy, HttpWebRequest originalRequest, Socket& socket)
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.CheckFinalStatus()
at System.Net.HttpWebRequest.EndGetRequestStream(IAsy ncResult asyncResult)
at System.Net.HttpWebRequest.GetRequestStream()
at System.Web.Services.Protocols.SoapHttpClientProtoc ol.Invoke(String methodName, Object[] parameters)

Our product is in use in a large number of establishments. This issue only occurs when connecting through a particular ISP.

Any help would be much appreciated.
Thanks
Ian