Hide your BIND version

Any user can discover the version of bind you are running with the following command: nslookup -q=txt -class=CHAOS version.bin.remote.dns.server

To hide your version of bind, add the following value to named.conf
version "[SECURED]“
in the options section section as follows:

options {
directory "/var/named";
version "[SECURED]“;
};

and restarted named.

courtesy http://www.tech-recipes.com/rx/201/hide-your-bind-version/