I am struggling to create a secondary DNS zone in ISPConfig3 On the principal server, the domain is responding OK. On the secondary server it creates an entry in /etc/bind/named.conf.local, which points to a file /etc/bind/slave/sec.example.tld, but this file is not created automatically. Is this correct or was some misconfiguration?
Which distribution? Are there any errors in your logs? What's the output of Code: ls -la /etc/bind/slave ?
Ensure that you added the IP adress of the slave in the "Allow zone transfers to these IPs (comma separated list)" field of the zone settings.
I explained the setting which is missing in your server in #10 of this thread. If you dont allow zone transfers, then they will not work.
You have to add the IP of the secondary server in the primary zone settings as described in my other post. But you added them in the settings of the slave zone.