We need to hide the server header in HTTP respones. When I set the urlscan parameter, Removeserverheader to 1, the server header is not present in an HTTP response test.
However, when the url for the login page to our site is accesed, a Page Cannot be Found error page displays with HTTP 400 bad request.
I set the value back to the default of 0, restart IIS and the login page works again.
The same thing happens when we try to use the Alternateservername option as well.