Plesk server DNS zones are not synchronizing with slave DNS server: transfer failed while receiving responses: REFUSED

Symptoms

• Plesk DNS zones are not synchronizing with the slave DNS server.
• The following error can be found on the slave server at /var/log/messages for CentOS or /var/log/syslog for Debian/Ubuntu:

  CONFIG_TEXT: May 20 04:59:49 serverhost named[31742]: transfer of 'example.com/IN' from 203.0.113.2#53: failed while receiving responses: REFUSED

• The following error can be found on the master server on at /var/log/messages for CentOS or /var/log/syslog for Debian/Ubuntu:

  CONFIG_TEXT:journalctl -u bind9 --since today 
  zone transfer 'nslookup.dk/AXFR/IN' denied

Cause

IP address of the slave server is not added in Tools & Settings > DNS Template > Transfer Restrictions Template. Transfer of DNS zones is allowed if slave server IP is added there.

Resolution

1. Log into Plesk
2. Add slave DNS server IP to Tools & Settings > DNS Template > Transfer Restrictions Template.