DNS health probe configuration in NODE

You can set the monitor at the node level vice the pool level by specifying a node specific health monitor. This will enable you to apply a unique monitor to each node. Have you tried this?

Here's the script we have in place for the SSH/script health check. We're using it to determine the health status of Splunk forwarders for logging purposes:

!/bin/sh
 remove IPv6/IPv4 compatibility prefix (LTM passes addresses in IPv6 format)
IP=`echo ${1} | sed 's/::ffff://'`
PORT=${2}
 set the pid file location and name
PIDFILE="/var/run/`basename ${0}`.${IP}.${PORT}.pid"
 kill off the last instance of this monitor if hung and log current pid
if [ -f $PIDFILE ]
then
echo "EAV exceeded runtime needed to kill ${IP}:${PORT}" | logger -p local0.error
kill -9 `cat $PIDFILE` > /dev/null 2>&1
fi
echo "$$" > $PIDFILE
 send request & check for expected response
ssh splunk@${IP} -i /config/ssh/ssh_host_dsa_key "/home/splunk/healthcheck.sh" > /dev/null 2>&1
 mark node UP if expected response was received
if [ $? -eq 0 ]
then
echo "UP"
fi
rm -f $PIDFILE
exit