#!/bin/sh
# munin plugin to show number of online network hosts on a subnet (needs fping)
# link with subnet name as suffix like _192.168.1
# will most likely need a custom timeout setting in /etc/munin/plugin-conf.d/munin-node
# for example:
# [net_hosts_*]
# timeout 20
#
# (c) 2011 jon@jon.bpa.nu
#%# family=manual

SUBNET=`echo $0 | cut -d'_' -f3`
TIMEOUT=50 # ms
RETRIES=0

case $1 in
	config)
	cat <<CFG
graph_title hosts on network $SUBNET.
graph_vlabel hosts
graph_category network
hosts.label hosts
CFG
	exit 0;;
esac

if [ $SUBNET != "" ]; then
	echo "hosts.value `fping -t $TIMEOUT -r $RETRIES -ga \"$SUBNET.0/24\" 2>/dev/null | wc -l`"
else
	echo "could not get subnet name ($SUBNET)"
fi