On each target server:

	1. install the nrpe "service" package:
		
		sudo apt-get install nagios-nrpe-server  // (I know, the server in the name is unfortunate)

	2. copy nrpe_local.cfg to /etc/nagios/nrpe_local.cfg

(for convenience, the text of nrpe_local.cfg (if cut and paste is easier than scp) :

##########################################################
#
#   nrpe_local.cfg
#
#   this companion cfg file to nrpe.cfg that contains all of 
#   the customized settings for dataone
#  
##########################################################


## the ip address of monitor.dataone.org
##########################################
allowed_hosts=129.24.0.12


##  the following are typical commands to be mapped
########################################################
command[check_disk]=/usr/lib/nagios/plugins/check_disk -w 20% -c 10%
command[check_users]=/usr/lib/nagios/plugins/check_users -w 20 -c 50
command[check_load]=/usr/lib/nagios/plugins/check_load -w 5,4,3 -c 10,6,4
command[check_zombie_procs]=/usr/lib/nagios/plugins/check_procs -w 5 -c 10 -s Z
command[check_total_procs]=/usr/lib/nagios/plugins/check_procs -w 250 -c 400
	
<<FILE

 
	3. restart the nrpe daemon with:
	
		sudo /etc/init.d/nagios-nrpe-server restart

	4. open up the firewall for port 5666:
		
		sudo ufw allow from 129.24.0.12 to tcp port 5666

	5. from the central monitoring server, test communication with:
		
		check_nrpe -H <target server IP> -c check_users
			GOOD: 		
				USERS OK - 1 users currently logged in...
			BAD: 
				CHECK_NRPE: Socket timeout after 10 seconds.
			(see http://www.debianclusters.org/index.php/Nagios_NRPE_Addon_Installation_and_Configuration
			 for more troubleshooting errors (toward bottom of page)