#!/bin/bash
NS="delta.memory-leak.de"
NSKEY="./ddns-key.memory-leak.de"
ZONE="memory-leak.de"
HOST="murnau.memory-leak.de"
TIMEOUT=3600
OLDIP=$(dig +short @$NS $HOST A)
NEWIP=$(dig +short myip.opendns.com @resolver1.opendns.com)
echo "old: $OLDIP"
echo "new: $NEWIP"
if [ "$OLDIP" != "$NEWIP" ]; then
    echo -e "
    	 server $NS
	 zone $ZONE
    	 update delete $HOST. 
	 update add $HOST. $TIMEOUT A $NEWIP
	 show
	 send" | /usr/bin/nsupdate -k $NSKEY
else
    echo "no update required"
fi