setting up Passive Host Checks for host behind a firewall

[kcarpenter@soleo.com]

HI,
I'm new and need to be pointed in the correct direction.

I have been tasked with setting up a Nagios server that monitors hosts behind a firewall. The Nagious server can not get to the host but the host can SSH and SCP the Nagios server.

I Started with configuring the Host Checks ..

I set up the server to send an SSH External Command "PROCESS_HOST_CHECK_RESULTS;server;0;Server is up" every 60 seconds to the Nagios Server.
with the intent that as long as Nagois gets this message the host is "alive".

I set up the server in Nagios to be
check_interval 0 ; do not preform host checks
active_checks_enabled 0 ; disabled
passive_checks_enabled 1 ; enabled

This works until I stop sending the External Command and the Host is continued to be shown as UP.

This seems simple enough but I can not find any documention on the host checks for host behind a firewall.

Where can I find documention on setting up this type of configuration?

Thanks

[abrist]

You need to set freshness for this check, so tat when the freshness time is surpassed without an incoming passive result, the host will be marked as DOWN. See:
http://nagios.sourceforge.net/docs/3_0/freshness.html