There is a lot of confusion about how IIS handles SSL. With all the confusion out there, I thought I should put together a quick post. This post will also explain the error message: At least one other site is using the same HTTPS binding and the binding is configured with a different certificate. My discussions this week were specific to SharePoint, but the confusion is with host headers in IIS.

I noticed what I think is a bug (or maybe a limitation) in SharePoint 2010. When I use PowerShell to create a Host Header Site Collection, SharePoint does not create a binding in IIS. If I add the binding manually, everything works great, but I would expect SharePoint to do this for. Am I missing something? The following PowerShell script will create a new web application. Note that I have the option to add a host header.