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

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

Check it.