Cassini vs IIS Authentication Issue

I have a C# webservice in .net 4.0. The webservice will create a file on a UNC path. If I let the Cassini web server in visual studio do the authentication it works fine. But if I change the application to use IIS (Windows 7) then the file doesn't get created but no error is reported.

If I change the location of the generated file to a local drive then Cassini and IIS both work fine, but only the Cassini web server will work for a UNC path.

I can only guess at the issue being authentication related, I've tried various combinations of the following;

• UNC path allow Everyone full access
• In IIS Windows Authentication
• In IIS Anonymous Authentication

My windows account has rights to create this file.

I haven't tried user impersonation and I haven't tried changing the anonymous credentials to something with more rights.

Does 开发者_运维知识库anyone know of security related differences between the Cassini web server and IIS which would cause these issues?

Many thanks, Mike

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The problem seems to be the identity of the Application Pool.

Check it.