Fix open DNS servers as reported by dnsreport.com

This seems to be a common theme for cpanel servers.

Please check your nameservers with this tool( https://dnsreport.com). If you get a red box that says Open DNS Servers, please fix it quickly by using the following instructions.

Edit /etc/named.conf and find the section that looks like this:

options {
        directory "/var/named";
        /*
         * If there is a firewall between you and nameservers you want
         * to talk to, you might need to uncomment the query-source
         * directive below.  Previous versions of BIND always asked
         * questions using port 53, but BIND 8.1 uses an unprivileged
         * port by default.
         */
        // query-source address * port 53;
};

Add this line after the directory line:

allow-recursion { 127.0.0.1; 123.123.123.123; 456.456.456.456; };

Change 123.123.123.123 and 456.456.456.456 with your dedicated server IP addresses and then restart bind.