I'm able to execute a stored procedure which queries a Linked Server directly, but when I call the same sproc though ASP.NET then I get the following error:
Access to the remote server is denied because no login-mapping exists.
When I execute it through SSMS, I am connected through my Windows domain account.
The site is ASP.NET with Forms Authentication on IIS 7 and SQL 2008 on my local machine.
The Linked Server is set up to "Be made using this security context" for all logins.