options {
  // set main directory
  directory "/var/cache/bind";
  // configure dnssec
  dnssec-validation yes;
  // session update key
  session-keyfile "{{ global_dns_session_key_path }}";
  session-keyname "{{ global_dns_session_key_name }}";
  session-keyalg "{{ global_dns_session_key_algorithm }}";
  // etc
  auth-nxdomain no;
  listen-on-v6 { any; };
};