Monitoring Failover on Two Windows Machines


I have two Windows servers delivering FTP. They are set to auto failover should the primary server fail using MS Clustering. This all works fine and I have no issue with any of it. However I would like Nagios to monitor the two nodes to alert if/when a failover takes place. I can easily monitior the FTP service on the primary so that if it fails I get a critical alert out of Nagios - very basic stuff. My question is how do I monitor the 2nd node to report that it has come up and has taken over the FTP duties? It does not run the FTP service unless the cluster manager tells it to start up, so there is no service for me to monitor. I want to keep watching port 21 and have Nagios do nothing until it responds that it is running. I have tried check_tcp and the -s and -e switches to wait for anticipated responses from the secondary node, but I can’t get them to work. Does anyone have an idea how to do this?

BTW - yes I know MS Cluster uses a third IP to Identify the FTP service and I am watching that, but that will only do me any good if both servers have failed.

Any help would be greatly appreciated!!