Nagios over Tunneled connections


Hi! This is my third day at my new job and here we are using Nagios. I managed myself to reconfigure it with not many troubles, but there is the last problem, a problem that I can’t solve without a bit of helop. Nagio is reporting, that few hosts and services are down (critical) all the time. But it’s not true. Everything it’s working right, but Nagio is reporting wrong.
I repeat, It’s only on few services and hosts. Those hosts are remote and we are connecting to them through SSH tunnels that are constantly open. ( Kind of ssh VPN ). Can somebody give me an idea of how to start with it all ? Thank you so much.