view "internal" {
      // This should match our internal networks.
      match-clients { 10.0.0.0/8; };
      // Provide recursive service to internal clients only.
      recursion yes;
      // Provide a complete view of the example.com zone
      // including addresses of internal hosts.
      zone "example.com" {
            type master;
            file "example-internal.db";
      };
};
view "external" {
      match-clients { any; };
      // Refuse recursive service to external clients.
      recursion no;
      // Provide a restricted view of the example.com zone
      // containing only publicly accessible hosts.
      zone "example.com" {
           type master;
           file "example-external.db";
      };
};