Cisco Secure Access Control Server (ACS) for Microsoft Windows sometimes allows the wrong configuration of an Authentication, Authorization, and Accounting (AAA) client with an IP address that overlaps with an existing entry. This configuration is possible even when the same protocol is selected. Whether the ACS accepts the overlapping IP address depends on the existing AAA client hostname.
These are the affected ACS versions:
ACS 3.3(1) build 16
ACS 3.3(2) build 2
ACS 3.3(3) build 11
This issue occurs due to the presence of Cisco bug ID CSCsc62488.
In order to resolve this issue, upgrate the software version to ACS 4.0 or ACS 4.1.