Remote host schecking over on-demand VPN links?

How can I have Nagios connect a VPN client before checking a host group – and then disconnect when finished? Specifically a PPTP or IPSec connection.

I’m trying to set up a Nagios monitor at my company as a replacement for Woodstone Servers Alive.
We take care of multiple networks for clients, and some of them have overlapping address schemes. Because of this, we can’t take the easy route and just leave VPNs up.

ServersAlive has the ability to use VPN services, on-demand, to reach remote networks, run checks, then disconnect before checking the next group. I’m sure Nagios can be made to do this as well, but have had no luck finding any help to set this up.

Smack me with a Clue-by-Four!

I think you could write a script that would open VPN, do the desired checks, and submit them as passive check results to nagios. At the end of the script close the VPN.