For some weird reason secondary Simple DNS server waits too long sometimes to update DNS records changed on primary DNS server. Especially if lots of records were changed in a short time.
It takes too much time to reload all the records manually in such cases. So we recommend to run the following script on your secondary Simple DNS server. The script forces the server to make the secondary zones update.
The script is created, tested and used many times by our team and our friends. And we feel the need to share it with our website community. Use it and enjoy!