Since the IIS instances are behind load balancers, the load balancer IP is inserted as the client-ip. To work around this, an IIS module is needed that replaces the client-ip value with the correct value. This is acomplished with two changes. First, the ACE must inject a speacial header value. In this case the header value is X-Client-IP. Second, the arr_helper module has to be installed and configured to replace the client-ip value with the correct value.
The module can be found here:
The module is installed in:
%PROGRAMFILES%\IIS\ARR Helper\
The configuration is located in:
%windir%\system32\inetsrv\config\schema\arr_helper_schema.xml