I have found interesting thing about IE that I would like to share with you. I was using forms authentication for login page. After successful login, ASP.NET creates an authenticated cookie and sends it to browser. That authenticated cookie is being send over to IIS to identify whether user is authenticated or not. This normally works fine. The issue was that it keeps bouncing back to login page even though after successful login. This was hapeening only with IE and works like a charm in other browser. Bit suprising to me. Is that IE culprit?
When I looked at that and found out IE wasn’t creating a form authentication cookie. Later I found out that IE blocks cookies from a server if domain name contains other than alphanumeric character. In our case we had an underscore in domain name and IE blocks cookies from a server because of that. Since IE doesn’t recieve forms authenticate cookie, during the subsequent request it is treated like unauthenticated request and that’s why it keeps bouncing back to login page.