Mike, I don't know what you are trying, but ...

I just took a fresh plain Windows Server 2008 R2 VM and installed Domino 9.0 with as few clicks as possible, e.g. all defaults but plus IHS. Of course I also installed a Domino admin in order to manage it.

Then I set up/configured that Domino server, again with as few clicks as possible, everything left as defaults (except enabling the HTTP task). I created SSL keys and certificates as usual, via an internal CA we have (Domino CA in our production environment). Enabled SSL, worked fine. Authentication was left as basic (default). No internet sites, no web configs, no nothing.

I used webadmin.nsf for the test. I fired it up and HTTP and HTTPS access worked fine to webadmin.nsf. I went to the Domino Admin and set the "Require SSL" flag on webadmin.nsf. Started a fresh IE browser and accessed the webadmin.nsf and voila, had the bug, i.e. the browser got into that endless redirection loop, even before the authentication came up (so like someone else also stated, I guess this will also happen for anonymous access).

Mike, I cannot understand how you are unable to reproduce this ... hard to imagine a simpler reproducible setup and bug.

By the way, out of curiosity, I also tested with the new IHS feature (that was the actual reason why I installed this test server, to evaluate IHS).

I also created the necessary SSL keys/certificates for it and activated it. Interestingly, when going through IHS, the problem did NOT show up.

However, I think not everyone will rush out and use IHS just because it appeared in the product ...