ACS 5.3, EAP-TLS Machine Authentication with Active Directory

Question

I have ACS 5.3. I am testing EAP-TLS Machine Authentication using Active Directory as an external Identity Store. II was testing and everything was going fine until I did some failure testing.
My problem: I deleted my computer account out of Active Directory and tried to authenticate my wireless laptop and it still worked when it should have failed.
Here is some of the output of the ACS log. You can see that the computer could not be found in AD and this was returned to the ACS. However, ACS still went ahead and authenticated the computer successfully.
Evaluating Identity Policy
15006 Matched Default Rule
22037 Authentication Passed
22023 Proceed to attribute retrieval
24433 Looking up machine/host in Active Directory - LAB-PC-PB.VITS.attcst.sbc.com
24437 Machine not found in Active Directory
22016 Identity sequence completed iterating the IDStores
Evaluating Group Mapping Policy
12506 EAP-TLS authentication succeeded
11503 Prepared EAP-Success
Evaluating Exception Authorization Policy
15042 No rule was matched
Evaluating Authorization Policy
15006 Matched Default Rule
15016 Selected Authorization Profile - Permit Access
22065 Max sessions policy passed
22064 New accounting session created in Session cache
11002 Returned RADIUS Access-Accept
I was assuming that if the computer was not found, the Identity Policy would fail, so I did not configure any authorization policy. Do I need an authorization policy to tell the ACS to fail the authentication if the machine cannot be found in AD? If I need an authorization policy, how do I configure it?
Note: In my Identity Store Sequence, I did enable the option:
For Attribute Retrieval only:
If internal user/host not found or disabled then exit sequence and treat as "User Not Found"
but this only seems to work for internal identity stores (at least based on my testing)
Under my Access Policy Identity tab, I configured the following Advanced features:
Advanced Options
If authentication failed
RejectDropContinue
If user not found
RejectDropContinue
If process failed
RejectDropContinue
And that didn't do anything either.
Any ideas? Thanks in advance.

Answer 1

Can try the following. Define an attribute to be retrieved from Active Directory and that exists for all objects. When defining the attribute it can be given a default value. Assign a default value which is a value that will never be returned for a real machine entry (eg "DEFAULTVALUE") and give it a "Policy Condition Name"
Then can make a rule in the authorization policy such as
If "Policy Condition Name" equals "DEFAULTVALUE" then "DenyAccess"