Portal Access doesn't SSO to Exchange 2010 OWA

Hi Michael,

 

My Exchange Engineer viewed the properties of the CAS server and it was set for "Integrated authentication" or "Basic authentication". We switched the CAS server to Forms-based and the SSO worked. However, my Exchange Engineer wants to switch it back to the two previous methods because OWA is working thru the ISA server this way. We are trying to replace out ISA with the F5. Now if I change the F5 SSO, the login will only work using HTTP Basic, but i still get prompted twice to login. Since only the HTTP basic would work (or forms based), it seems to rule out that NTLM or Kerberos is being used. Is there something I'm missing to get HTTP Basic to work with single sign-on?