Shibboleth SP browser loops when attempting to connect to protected site

[Peter Schober]

* String76 <hortonb at kayacorp.com> [2014-08-12 16:24]:
> So I imported the SP xml metadata (which of course includes the ACS url as
> Scott indicated) into the idP and now am getting the site to load when
> selecting the web app from my idP page.  Also, I went ahead and configured
> the entire site to be protected and moved my app into the root of the site. 
> When my idP directs me to the protected site I am prompted for username/pass
> but would have expected Shib to authenticate me based on credentials passed
> from the idP.  Within IIS 7.5 the site is configured for basic
> authentication.  Am I not passing the credentials properly from from the idP
> or is this even possible with IIS?

The IDP is not sending your username and password to the IDP to
satisfy HTTP Basic Authentication there, if that is what you're
asking.
On the SP side you configure authentication/authorization according to
the SP documentation, you don't additionally require HTTP Basic Auth
in the webserver (or from within the application).
-peter