Thought is was time to bring this to the Stack. We have IIS 7.5 (classic mode), .net 2.0 on Windows Server 2008. The app was upgraded from .net 1.1 with no issues/changes needed. It was migrated from Server 2000. Once in its new home, Forms Authentication started to hiccup for IE users. IE users can log in, arrive at the successful login destination page which has a paragraph of text, a WebControlLibrary sound bit (mp3) and an asp button. Upon button click, IE users are immediately sent back to login. It happens so fast, does not appear to postback, but fiddler says it does and shows it posts back twice with a sneaky 302 redirect mixed in.
On fiddler, Firefox shows no 302s and works fine as does Chrome. This only happens externally to our network as well, on IE7/8, internal testing is fine.
I have seen where users have reported that an underscore in the url can cause this..don’t have one. Mixing authentication modes in IIS 7.5 can cause issues, we use classic mode. I have seen where javascript used to call the postback for the button can cause this, we use standard .net button onclick event in code behind (that simply checks a page number then does a response redirect to the next page in the app.)
I have roamed google and bing (and here) for the better part of a few days to no avail. I apologize for the vagueness of the question.
EDIT:
No underscores in server name. Here is the process as visible by a user. You Login, login page refreshes and asks you to verify you are who you say you are. If you say yes, you go to instructions.aspx. This pages buttons will postback as you hit “continue”. IE dies on first conitnue click and note the odd stuff in fiddler…FF is fine and moves on to rest of app.
IE 8
Result Protocol Host URL Body
200 HTTP CONNECT / 0
200 HTTPS xxxxxx.com / 12,354
200 HTTPS xxxxxx.com /login.aspx 8,139
302 HTTPS xxxxxx.com /login.aspx 137
200 HTTPS xxxxxx.com /instructions.aspx 6935
302 HTTPS xxxxxx.com / 131
302 HTTPS xxxxxx.com /logout.aspx 130
200 HTTPS xxxxxx.com /login.aspx 12,354
302 HTTPS xxxxxx.com /insturctions.aspx 167
200 HTTPS xxxxxx.com /login.aspx?ReturnUrl=&...
FireFox
Result Protocol Host URL Body
200 HTTP CONNECT / 0
200 HTTPS xxxxxx.com digicert.com 12,354
200 HTTPS xxxxxx.com /login.aspx 8,139
302 HTTPS xxxxxx.com /login.aspx 137
200 HTTPS xxxxxx.com /instructions.aspx 6935
200 HTTPS xxxxxx.com /images/xxx.jpg 47
200 HTTPS xxxxxx.com /images/xx2.jpg 46
200 HTTPS xxxxxx.com /instructions.aspx 12,354
200 HTTPS xxxxxx.com /images/xx3.jpg 49
It appears that as of IE8, the forms tag attribute “domain=’domain.com'” is required. Found this blob post Persistent Cookies Fail in IE8 and Windows 7
and this has solved the issue based on prelim testing.