dnsdiff.sh

#!/bin/bash

# Based on https://stackoverflow.com/a/29079962/10955319

SOURCE_NS=$1
DEST_NS=$2
ZONE=$3

if [ "$SOURCE_NS" == "" ] || [ "$DEST_NS" == "" ] || [ "$ZONE" == "" ]
then
	echo "USAGE: $0 source_nameserver destination_nameserver zone_name_or_file"
	exit 1
fi

if [ -f $ZONE ]
then
	ZONES=$(cat $ZONE)
else
	ZONES=($ZONE)
fi

diff <(sort -u <(for host in $ZONES; do dig +nottlid +noall +answer @$SOURCE_NS $host ANY; done) ) \
	<(sort -u <(for host in $ZONES; do dig +nottlid +noall +answer @$DEST_NS $host ANY; done) )