IIS7 Won’t Respond Over SSL if No Certificate is Selected

Ugh, while the title of this post doesn’t sound like that much of an issue chalk this one up to an experience I hope someone else doesn’t have to deal with.

We had an issue with our A/C unit in our data center last night and several of our servers were shut down due to excessive temperatures.  We are slowly brining them up as we are managing the cooling and they are all fairly coming up as normal. Some of the older servers reported errors with batteries or failed drives but these are fairly routine.

However, we had one of our brand new servers start up with seemingly no issues but IIS 7 was not responding to web requests.

This server serves up only two web applications over SSL and has worked fine for the last month that it has been in service.

Looking at the IIS logs, event viewer and any other sort of diagnostic tool we could think of reported no errors at all…and no connection attempts either.  Connecting from the local host offered no error messages.  Connecting through Fiddler2 only showed the cryptic message, “the server has actively closed the connection”.

Finally after restarting the entire server, the IIS service, the web site and the app pools we were grasping at straws.  Bindings were correct, permissions were correct, doing a “netstat –an” revealed the server was indeed listening on port 443.

In the end, what solved it is in the binding settings the Certificate dropdown showed None.  I selected the self-signed server certificate and the whole thing suddenly came alive.  I attempted to set the SSL certificate back to None, which wasn’t an option anymore.

Of course that makes sense.  How can you serve up SSL traffic when there is no certificate to authenticate the request with?  However, why a server restart caused the certificate to no longer be selected is beyond me. 

And why did IIS never throw an event or some type of log error that said, “Hey, you’re trying to serve SSL but no certificate is selected!”???

Anyway, hopefully this will show up on a Google search for someone else.  Cheers. Smile

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Matt Penner

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