$TTL    86400
@   IN  SOA  etcdns.local. root.etcdns.local. (
             100500     ; Serial
             604800     ; Refresh
              86400     ; Retry
            2419200     ; Expire
              86400 )   ; Negative Cache TTL
    IN  NS  ns.etcdns.local.
    IN  A   127.0.0.1

1 IN PTR m1.etcd.local.
1 IN PTR m2.etcd.local.
1 IN PTR m3.etcd.local.