options {
  directory             "/var/cache/bind";
  recursion             yes;
  dnssec-validation     auto;
  listen-on             { 10.10.0.159; };
  listen-on-v6          { none; };
  forward               only;
  forwarders            {
                          8.8.8.8;
                          8.8.4.4;
                        };
};