This client can update v4 and v6
It can update v4 and v6 simultaneously.
Set HOSTNAME to your Hostname which you want to update.
If you want to update more than one with the same ip, then
HOSTNAME="host1,host2"
Set CLIENTKEY to your Update-Key
If you want to update IPv4 AND IPv6, then let the values be true.
Change the values to false if you only want to change one IP.
Now make your script executable
chmod +x dynupdate.sh
The Script has no Daemon. You have to put it in your e.g. cronfile
crontab -e
I run this Script every 5 Minutes
*/5 * * * * /<folder where you save it>/dynupdate.sh