$ORIGIN <domain>.
$TTL 1D
@     IN SOA   <hostname> <hostname> (
                        <date>    ; serial
                        8H        ; refresh
                        4H        ; retry
                        4W        ; expire
                        1D )      ; minimum

                NS      <hostname>
www             CNAME   <hostname>
localhost       A       127.0.0.1
<hostname>      A       127.0.0.1

_xmpp-client._tcp.<domain>. 18000 IN SRV 0 5 <c2s_port> <hostname>.<domain>.
_xmpp-server._tcp.<domain>. 18000 IN SRV 0 5 5269       <hostname>.<domain>.