Hi,

On Fri, Jan 16, 2015 at 2:27 AM, <cprice@its.to> wrote:

PLatform is RHEL 6 Update 6.

Relevent RPMS are :

sssd-ad-1.11.6-30.el6.x86_64
krb5-workstation-1.10.3-33.el6.x86_64

Pam was setup using " authconfig --enablesssd --enablesssdauth
--enablemkhomedir --update"

I have test users successfully authenticating against a test domain server
with both the test linux RHEL6U6 box and the Windows 2008R2 AD server on
an isolated subnet.

After I login to the RHEL6U6 box with an AD user via either ssh, or via
the console I cannot run 'su - <username>' to any other user, either AD
based or local password file based. All I get is a 'incorrect password'
error message.

In your client machine SeLinux is enabled (means enforcing)?  Most of the time that could be the problem.

Please check that.