check_rsync is a Nagios NRPE plugin for checking/displaying various rsync aspects like version, protocol, capabilities and modules. You can instruct the plugin to raise alarms if those aspects do not conform to your baseline.
check_ad version 1.4 supports Windows 2008 platforms. As you may know, check_ad requires Microsoft tools dcdiag and netdiag. A Windows 2008 DC has dcdiag as a standard component, while netdiag should be installed (Windows 2003 version works just fine).