A client has several servers hosted which are running IIS 7. From any other server within the same hosting server there are no problems accessing our ASP.net website but from the clients office they get a 403 error with no sub code.
I've checked the IIS logs, there is nothing being logged for the remote attempts. I've also enabled Failed Request Tracing, there is also nothing being logged. I've verified all logging is working from within the hosted domain (from a different server).
When we try to telnet to port 80 on the IIS server it succeeds from the clients office and when I stop the website in IIS then telnet fails so it looks as if it's getting to the server.
I've created a simple IIS site that simply serves up an Image, this has the same issue. I've also enabled Anonymous authentication and impersonation in the web.config which again works from a server in the same subnet but not the client site.
The hosting provider assures us that port 80 is open and that we shouldn't have any problems.
Using the DevTools in chrome simply shows 403 and gives an error viewing the response object.