We have built RS on custom security authenication. It works over the internet fine over SSL but as soon as customer tries to run it the Reporting Services Logon Box does not prompt and they get an error accessing the ReportServer site through the server dialog box. Therefore i am assuming something on the customers firewall is blocking the logon prompt. Has anyone else had this issue and what rules on the firewall are needed for this to work? Thanks

Hi darrenmog, The port 443 must be opened. Thanks, Jin ChenJin Chen - MSFT