No connection could be made because the target machine actively refused it

[TheRefactornator]

It sounds like a proxy server (I suspect MS ISA) authentication problem on the dev machine:

Code running in a console application in development: fine because the application is running in the context of a user account (you) that has the correct security context to make a request through the proxy server.

Code running in an ASP.NET web application in development: doesn't work because the application is running under a system account (NETWORK SERVICE, LOCAL SYSTEM whatever) and the proxy server refuses to serve the request for that user.

Code running in an ASP.NET web application in the live environment: might sometimes just work without any impersonation / changes from the dev code that didn't previously work and this can be confusing. It depends on the environment setup because sometimes live servers are positioned where they don't make requests through a proxy that requires authentication.

I seem to remember this exception containing an IP address that tells you specifically which 'target machine' refused the connection.

Code based impersonation / user context switching is a solution I've used in the past for this problem: e.g. switch to a user account (usually a real windows domain user account specifically created for this purpose i.e. a service account with a password that never expires) that can definitely burrow through the proxy server when making an outbound HttpWebRequest and undo impersonation immediately afterwards. Doing it this way meant the code worked in all environments regardless of infrastructure configuration.

[fullyautomatix]

Have you tried disableloopbackcheck and disablestrictnamechecking in the registry?

Ian

No I did not try that, but will do so and see if that has any affect. Thanks.

[biondani]

Have you tried disableloopbackcheck and disablestrictnamechecking in the registry?

Ian

[fullyautomatix]

Edited, i'd had this before and was trying to think how it was resolved, as i remember, it was caused by the corporate firewall settings on our client machines blocking the call. Worked ok once we uploaded to the dev box that had no such rules applied. Your case sounds different though if other sites on the same box are responding. Do the IIS logs on the box shed any more light?

I have just published the web page on a proper website and tested it and it works. The same code fails using localhost.

Even more weird is the fact that requests to some websites work and some do not. You are right that it could be firewall but it could be a combination of firewall and something else.

I might just leave it at that and wont bother testing on my local machine.

[Durbs]

Have you tried using impersonation? Or is it just running as the standard local network service account?

Edited, i'd had this before and was trying to think how it was resolved, as i remember, it was caused by the corporate firewall settings on our client machines blocking the call. Worked ok once we uploaded to the dev box that had no such rules applied. Your case sounds different though if other sites on the same box are responding. Do the IIS logs on the box shed any more light?

[Durbs]

Have you tried using impersonation? Or is it just running as the standard local network service account?

[fullyautomatix]

Hi Chaps

I normally do not post asking for a solution but this one has really driven me mad.

I am using the HttpWebRequest object in the .NET framework to perform a really normal 'GET' request. The target is on IIS.

If I run the code through a console application it runs fine and I get a response back.

If I run it through a web app ( ASP.NET, C#) I get the above exception.

Two days of googling and troubleshooting has got me nowhere.

Another thing is, on that same IIS box, there are two more websites which return a response, but the rest give me that exception.

Any clues? Anybody encountered this problem before ?