Bind : max open files (1024) is smaller than max sockets (4096)

You may see the following notice in the system log. You need to raise the max open file in both system limit file and named configuration.

Edit /etc/security/limits.conf and add :

named soft nofile 4096

Inside the /var/named/chroot/etc/named.conf, add in the option section :

files 4096;