For GTM, I don't use any CDEFs. I'm not sure how to solve the problem, except to increase your DNS hit count... For testing, you could use this script (courtesy of F5) to generate queries:
!/bin/bash
Initialize Variables
COUNT=0
LOGEVERY=10
LOGCOUNT=0
Gather Test Data
echo -n 'Enter DNS Server IP addres: '
read DNSIP
echo -n 'Enter FQDN for resolution: '
read FQDN
echo -n 'Enter number of resolution attempts: '
read LIMIT
echo -n 'Specify output file: '
read OUTFILE
Check for $OUTPUT file exists, if the file exists and IS NOT empty
clear the file with cat /dev/null to empty it out.
if [ -s $OUTFILE ]
then
echo 'Output file $OUTFILE exists and is NOT empty... Resetting file.'
sleep 1
cat /dev/null > $OUTFILE
fi
Dig Loop
while [ $COUNT -lt $LIMIT ]
do
dig +short @"$DNSIP" $FQDN A >> $OUTFILE
if [ $LOGCOUNT == $LOGEVERY ]
then
echo "DNS Requests sent: $COUNT"
LOGCOUNT=0
fi
COUNT=$(($COUNT+1))
LOGCOUNT=$((LOGCOUNT+1))
done
exit