You may run into a case where you are running a name server (perhaps a caching-only name server) that is not allowed to communicate with Internet name servers. The most common case for this is a local caching name server being blocked by a corporate or <acronym title="Internet Service Provider">ISP</acronym> firewall.

If you are set on using your caching name server instead of the server that is allowed through the firewall, you can force your BIND name server to forward all <acronym title="Domain Name Service">DNS</acronym> requests to the approved server(s) for you. Simply add the following configuration to the options {}; portion of your named.conf file.

options {
  forwarders { 172.16.9.9; 172.16.9.10; };
};

Remember to replace the IP addresses I've used with the IP addresses of your approved DNS servers.