"rndc: connection to remote host closed." What does this mean ?
Attempting to restart bind
Waiting for bind to restart.... . . . . . . . . . . finished.
rndc: connection to remote host closed
This may indicate that the remote server is using an older version of the command protocol, this host is not authorized to connect, or the key is invalid.
To fix this issue you may try running /scripts/fixndc.