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Cory_50405's avatar
Cory_50405
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Sep 03, 2013

LTM attempting reverse lookups on pool members

Here's the situation I am encountering. I have a virtual server setup to listen on all ports, with a UDP profile applied to it. There's nothing special about the UDP profile except that we're doing...
availability
management
TMSH
Cory_50405's avatar
Cory_50405
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Sep 04, 2013

Here's my external monitor. Nothing in here about DNS lookups:

!/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 splunkf5@${IP} -i /config/ssh/ssh_host_dsa_key "/home/splunkf5/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

Cory_50405's avatar
Cory_50405
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Sep 04, 2013
I can't speak to the .sh file running on the remote hosts. From the LTM's perspective, we're just taking the output and determining an up/down status. Nothing that the remote hosts are doing in that script should matter to LTM, only that we're getting a response from the host to evaluate for an up/down decision. The key file that we're presenting to the remote hosts for SSH key authentication is just the LTM's host key. Nothing about the remote hosts is specified in the key.