ACS 4.x does require External Database IP address when using Windows. If you want to authenticate AD with ACS 4.x you need to have the ACS software (if using Windows version) installed on a Member Server or Domain Controller on your network.
If you are using an ACS Solution Engine then the Remote Agent software must be installed on a Member Server or Domain Controller on your domain.
The ACS Software would then detect the available domain and should be able to authenticate AD accounts.
You can check the following for the Post Installation Tasks for an ACS for Windows:
BenefitsDocumentationPrerequisiteImage Download LinksLimitationsSupported PlatformsLicense RequirementsTopologyStep-By-Step ConfigurationConfigure Virtual ServiceActivate the virtual service and configure guest IPsConfiguring UTD (Service Plane)Configurin...
Login to the FXOS chassis manager.
Direct your browser to https://hostname/, and log-in using the user-name and password.
Go to Help > About and check the current version:
Check the current version availa...
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...