DNS zones are not transferred from master to slave server.
Connection from slave to master server is not possible through 53 port:
# telnet 192.168.1.1 53
Firewall prevents connection on port 53.
Connection has been blocked by SElinux policy.
Disable Selinux temporary to check if connection works, check Audit logs on both servers (/var/log/audit/audit.log):
# setenforce 0
Make sure that 53 port is not blocked by iptables on both servers.
- Make sure that 53 port is listened by named service:
# netstat -ntpl | grep 53
tcp 0 0 :::53 :::* LISTEN 1164/named